US3788224A

US3788224A - Nested wad column and method of shot shell loading

Info

Publication number: US3788224A
Application number: US00785017A
Authority: US
Inventors: E Merritt
Original assignee: Federal Cartridge Corp
Current assignee: Federal Cartridge Corp; Federal Cartridge Co
Priority date: 1966-06-24
Filing date: 1968-12-06
Publication date: 1974-01-29
Anticipated expiration: 1991-01-29

Abstract

A wad column which is adjustable to an infinite variety of lengths, during loading of the shell, to accommodate any of several different loads. Also, a method of loading shot shells in which the effective height of an overpowder wad is varied, as the wad is seated, to accomodate a particular shot and powder charge combination within the shot shell case.

Description

United States Patent 19] Merritt NESTED WAD COLUMN AND METHOD OF SHOT SHELL LOADING Edward E. Merritt, Anoka, Minn.

Federal Cartridge Corporation, Minneapolis, Minn.

Filed: Dec. 6, 1968 Appl. No.: 785,017

Related U.S. Application Data Continuation of Ser. No. 637,578, May 10, 1967, abandoned, which is a continuation-in-part of Ser. No. 560,221, June 24, 1966, abandoned.

Inventor:

Assignee:

U.S. Cl. 102/42 C, 102/95 Int. Cl. F42b 7/08 Field of Search 102/42, 42 C, 95

References Cited UNITED STATES PATENTS 2/1964 Lyon 102/95 X 9/1966 Atkins et a1 102/42 C Primary Examiner-Robert F. Stahl Attorney, Agent, or FirmSchroeder, Siegfried, Ryan & Vidas [5 7] ABSTRACT A wad column which is adjustable to an infinite variety of lengths, during loading of the shell, to accommodate any of several different loads. Also, a method of loading shot shells in which the effective height of an overpowder wad is varied, as the wad is seated, to aEEofiiodate a partTEuTar" EHEt and powder charge combination within the shot shell case.

20 Claims, 21 Drawing Figures PATENIEUJANES 1974 sum 1 0r 4 NVENTOR, EDWARD E. MERR/TT 5M, MW, M04 502 gjw lfTUP/VEVS PAIENIED JAN 2 9 m4 IIIIII/A sum 3 m a,

x N/ll/M WBW Madam/mg;

INVENTOR.

fowAlaof. MERRITT ATTORNEY;

PATENIED JAN 2 9 i974 SHEET 8 BF 4 FIE 19 FIEZO T A 5 5 W WM w m5 J A D. u m M M M NESTED WAD COLUMN AND METHOD OF SHOT SHELL LOADING CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of my co-pending application Ser. No. 637,578, filed May 10, 1967, which inturn is a continuation-in-part of my co-pending application Ser. No. 560,221, filed June 24, 1966, both applications are abandoned and assigned to the assignee of the present application.

BACKGROUND OF THIS INVENTION This invention relates to shotgun shells, and more particularly to a novel wad column and combination shot protector for a shotgun shell. The device comprises two members cooperating to provide an adjustable structure which adapts to various loads of both powder and shot.

Shot shell wad designers have strived for wad columns that, in addition to scaling the powder gases behind the shot charge, have been light compressible. Wad lightness permits the use of less propellant to obtain the same shot load velocity and reduces the amount of recoil. Compressibility is desirable to cushion the impact generated by the expanding powder gases so as to set the shot load in motion more gradually. This reduces undue deformation of the shot as well as lessening maximum pressure levels in the shell to achieve a given velocity of the shot load.

Various cushioning structures including air enclosing ones have been proposed as a means of achieving these characteristics of lightness and compressibility. These have generally involved folding or assembling paper or fibrous materials to create air pockets assembling together paper or plastic cups, or providing structures that will collapse purposely. Another approach has been to fill a flexible container with some compressible material such as cork and the like. Of those known, all have one or more serious drawbacks such as being too weak to maintain the air bubble, or if strong enough, then too heavy.

Previous collapsing devices, while evidencing some measure of success, have lacked the ability to conform to varying internal shell volumes except within comparatively narrow limits, and have been more costly to manufacture than is necessary. The problem is aggravated by the fact that large quantities of shells are manufactured in at least the three major gauges, i.e., 12 gauge, 16 gauge and 20 gauge. Even more importantly, depending upon the purpose for which the shell is manufactured, the shot size, and a number of other factors, the size of either the powder load, the shot load, and very often both, may be substantially different for the different types of shell of the same gauge. Furthermore, there are variations occurring within a given loading of powder and shot because equal charge weights of different shot sizes occupy different volumes. These variations in space demands call for variations in wad column length for best loading pressures and shell performance.

SUMMARY OF THE INVENTION This invention is a wad column that is not only adapted to easy, inexpensive manufacture in different sizes in accordance with the different gauge shells, but

more importantly, is of such a construction that a single size of wad column is readily adaptable within each gauge category in an infinite variety of lengths for the different loads and any other different space requirements. It fills a void in the wad column art, as no previously known wad column achieves all of these ends quite so thoroughly.

The device of the present invention satisfies these and other requirements and, in one form, comprises two nested members or pieces having portions spaced by a compressible air gap or bubble which varies during manufacture in accordance with the available spacing within the particular shell casing. That is, the members may be only modestly telescoped so as to fill a large area within a shell incorporating a light load or may be more heavily compressed and contracted so as to fill a smaller space in the same size shell filled with a large load, whether it be shot load, powder load, or both. This form of the wad column of the present invention may comprise a shorter plastic cup, the mouth of which telescopically receives the base of a longer plastic cup which preferably also acts as a shot protector, concentrator or pouch. Such a nested column permits the products of a pair of simple molds to be loaded in standard equipment for a large variety of loads. The need for a particular wad system for each load is eliminated and with it the need for several molds and several feed adjustments on a loader. The lower end or base of the shorter of the two cups (which acts as an overpowder or sealing wad in contact with the powder load) is preferably formed with a shallow concavity so as to define a short, relatively thick flange around the lower edge of the disc or base of the bottom cup.

An important feature of this form of the invention is its ability to alter or self-adjust to various loads of both powder and shot by means of reluctant telescoping action. Reluctance of the shot load cup to telescope into the lower overpowder wad or sealing cup results partly from increased engagement between the two cups and partly by reason of the two cups fitting so snugly with respect to each other that air is trapped and compressed between them as they are forced together. Nevertheless under the forces applied by a loading machine, the two cups may be forced more nearly together to provide an infinite variety of space occupied by the wad column (within the limits of its total potential) which is quite sufiicient for all possible variations within a given gauge of shotgun shell.

Another form of the invention comprises a cup shaped overpowder wad with short, thick, downwardly extending flanges and a flexible center support post which contacts the bottom of a shot cup. The shot cup has an exterior diameter approximately equal to the interior diameter of the overpowder wad cup so that it is supported by the collapsible post. The post structure is such that it can be partially collapsed during the load- 7 ing process to accommodate the predetermined load,

powder, thereby eliminating telescoping of the pouch and wad portions during loading of the shell. Such telescoping is sometimes undesirable because the upper edges of the overpowder wad are forced outwardly as the shot cup is pressed down thereby creating a bulge in the shell casing which is visible from the exterior. This form of the invention provides a stable wad column structure because a broad support platform is created by rolling back the center post. The tapered post further provides an increasing resistance to increasing amounts of rollback. This structure provides .a

smoothly collapsing cushioning structure upon shell fir- 7 able during the loading process to accommodate any of several different powder and shot loads.

Another object of the present invention is to provide an improved wad column or shot shell that is lightweight and cushions the shocks of firing in a controlled manner.

Another object of the present invention is to provide a nested wad column which greatly simplifies the cost of loading a shell since the column is infinitely adjustable in length within its potential, thus eliminating the need for several different wad columns for each gauge v shell.

Another object of the present invention is to provide an improved shotgun shell and wad column which evidences all the desirable features of prior constructions including lightweight and optimum cushioning, and which at the same time improves the desired flight characteristics of the shot leaving the barrel of a gun.

Another object of the present invention is to provide.

a two piece wad column easily molded from inexpensive material in simple inexpensive molds, loadable as separate pieces or assembled, and yet which will contribute minimally to recoil and have relatively short travel of the wad column beyond the gun barrel.

A further object of the present invention is to provide a method of loading shot shells whereby any chosen laod can be ac-commodated by simply varying the effective height of the overpowder wad after seating it in the shell.

A still further object of the present invention is to provide a method of loading shot shells in which a variety of loads can be accommodated by rolling down, by various amounts, the center post of an overpowder wad, thereby reducing the wad inventory signif-icantly and reducing the number of wads which need be loaded into the shell.

BRIEF DESCRIPTION OF THE DRAwiuos These'".na"f..si;ersa s and 'ad'vassg sf the invention will be more apparent upon reference to the following specification, claims and appended drawings wherein:

FIG. 1 is an exploded view of one form of the novel nested wad column of the present invention showing the lower and shorter sealing cup and the upper and longer shot protecting cup;

FIG. 2 is a vertical section through the sealing cup of FIG. 1;

FIG. 3 is a vertical section through the shot protecting cup or shot pouch of FIG. 1;

FIG. 4 is a vertical cross section through the assembled cup forming a wad column for a shell having light powder and/or shot loads;

FIG. 5 is a view similar to FIG. 4 except that the cups are shown telescoped or nested in a relationship they assume in a shell having moderate powder and/or shot loads;

FIG. 6 is a vertical section through a loaded shot shell corresponding to approximately a maximum load of shot and powder for the wad column of FIG. 1;

FIG. 7 is a vertical section through a modified form of the cup shaped sealing wad of the present invention illustrating one arrangement for increasing the resistance or reluctance of the overpowder sealing wad to receive the shot pouch;

FIG. 8 is a plan view of the cup wad of FIG. 7;

FIG. 9 is a vertical section through a shot retaining cup or shot pouch of modified construction having a supporting structure on its bottom offering added resistance to nesting or telescoping of the shot pouch into an overpowder cup beyond a certain depth;

FIG. 10 is a bottom view of the shot pouch illustrated in FIG. 9;

FIG. 11 is still a further modified form of the shot protector cup according to the present invention providing structure for increasing the rapidity with which the shot is disbursed upon the shot pouch leaving the gun barrel;

FIG. 12 is a top plan view of the shot pouch illustrated in FIG. 11;

FIG. 13 is an illustration of the wad column of the present invention as it appears after having been fired from a shotgun and recovered after use;

FIG. 14 is a cross sectional view of a modification of the wad column of the invention utilizing a collapsible center post to provide increasing resistance to increasing telescoping of the wad and shot pouch;

FIG..15 is a top view of the cup wad structure and center post of FIG. 14;

FIG. 16 is a vertical section through a further modification of a telescoping shot pouch and wad wherein the wad has a chamfered exterior at its upper edge to eliminate bulges in the shell casing upon partial telescoping of the wad and pouch;

FIG. 17 is a vertical section through the presently preferred overpowder wad with a center post adapted to be rolled back;

FIG. 18 is a top view of the wad of FIG. 17;

FIG. 19 is a vertical section through a shell in a loading machine illustrating how rollback of the center post is accomplished;

FIG. 20 is a bottom view of the tool, also shown in FIG. l9 v hich i s used to rollback the center post; and

FIG. 21 is a vertical section through a loaded shell contain-ing the overpowder wad of FIG. 17 rolled back to approximately the position it would assume under a maximum load of shot and powder.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, in FIG. 1 a first form of the wad column of the present invention generally indicated at 14 includes a shot pouch or longer upper cup 15 illustrated as provided with slits such as the ones shown at 16 which, in this case, divide the wall of the cup into quadrants. These slits need not extend the entire depth of the cup and in any event stop some short of the base 26 for reasons which will be obvious from the discussion below. Also forming a part of the overall wad column generally indicated at 141, in addition to the longer cup or shot protector 15, is a lower or shorter cup 17 which receives through its mouth 18 the bottom or base 26 of the shot pouch 15. The shorter sealing cup 17 resists any substantial insertion of the pouch 15 into the sealing overpowder cup, and this resistance is particularly evident when the lower cup is confined within a shell case. The resistance to insertion results from the combination of the wedging or frictional engagement between the walls of the two cups (which increases by reason of the tapered construction of the walls of the lower cup 17) and the fact that the two cups tend to trap air between them further resisting nesting or telescoping. The overpowder wad in the form of sealing cup 17 is provided with a disc shaped base or web 19 which acts very much like a familiar air pump or water pump piston leathers to seal the gases of combustion generated by the burning powder behind it. It is preferably provided with a short, thick annular flange 20 defining a shallow concavity somewhat in the nature of a dish adapted to overlie and engage the powder load in the shot shell.

In FIG. 2 is shown the overpowder wad portion of the wad column 14 by itself. This portion 17 of the wad column serves the function of sealing the gases of combustion in the usual manner and also importantly cooperates with the cup 15 to provide a variable volume within the shell. Below are given some specific dimensions that have been found satisfactory for wad columns for use in 12 gauge shotgun shells. These figures are for an overpowder wad 17 and cup wad 15, both made from low density polyethylene. By low density polyethylene is meant a polyethylene having a density of from 0.912 to 0.925. Densities of 0.925 and 0.940 are usually called intermediate densities and densities of 0.940 to 0.965 are called high densities although there is some overlapping of the groups as commonly defined. Medium and high density polyethylenes will work as well and may be more readily available than the low density material.

In one embodiment constructed in accordance with the present invention, both the

cups

15 and 17 were made from a commercially available polyethylene material sold under the trade name DYNII rated as 0.917 density and 1.5 melt index. Polyethylene having densities from 0.915 to 0.965 can be used with melt indices from 6 to 0. In addition, any of the related polyolefins such as polypropylene and the like can be used for forming one or both of the cups of the present invention as well as a wide variety of other materials. While all of the materials mentioned are commercially available, it is understood that the densities and melt indices given are by way of example only, since available information is limited and the molecular weight figures for plastic material of different manufacture are not always in complete agreement.

The thickness of the base or web 19 for the polyethylene materials described above varies in accordance with the material used and the particular application. In general, disc shaped base or web 19 must be thick enough and strong enough to resist blowing inwardly upon the application of the force of the expanding gases generated by the burning powder. For a 12 gauge shell, the web is usually in the neighborhood of from 0.062 to 0.068 of an inch thick. The flange 20 may have a thickness of from 0.30 to 0.35 of an inch and a length on the order of the thickness of web 119, i.e., a flange length projecting downwardly from the web of from 0.067 to 0.073 of an inch. The flange is long enough to reach the barrel of the gun after the wad is shot from the shotgun shell but must be short and thick enough not to ring out easily, i.e., leave rings of plastic, at a choke if one is used on the gun. In general, a relatively short, thick flange is less: likely to leave rings of material at the choke than along thin flange, or the short thick flange leaves less bulky rings if it does.

The annular walls of the upper portion of the sealing cup 17 as they extend away from the base 19 preferably gradually thin so that the inside of the cup beginning at the mouth 18 and extending down to the base or web 19 gets progressively smaller. This taper is not essential to the operation of the wad column since by a suitable variation in dimensions or otherwise adequate friction between the telescoping or nesting walls may be obtained, i.e., such as by making the outer diameter of cup 15 slightly larger than the inner diameter of cup 17.

When the taper is used, it is not great. For example, in the same 12 gauge shell wad column as described above when the wall at mouth 18 was 0.020 to 0.025 of an inch thick, just above the web the wall is from 0.025 of an inch to 0.030. The larger figures go together. In the form of the invention in FIGS. 1 6, there is approximately 0.005 of an inch difference in the thickness of the wall at the mouth 18 as compared to the thickness near the web 19. In inside diameter, therefore, the sealing cup 17 reduces from mouth 18 to web 19 by 0.010 of an inch. Where the wall joins the web 19, there is a radius 22 comparable to the similar radius 21 except that radius 22 is about twice as great (being approximately one-sixteenth of an inch). The reluctance or resistance to telescoping is provided if the walls of the lower nesting cup .17 are tapered, must stretch, or are otherwise manufactured so as to resist with progressive vigor the telescoping together of the two parts.

In FIG. 3 is shown one configuration for the cup 15. Cup 15 is of such dimensions that it will just fit inside the top of mouth 10 of the overpowder wad cup 17. The shot retaining cup is most easily manufactured without slits and if the slits are put into the cup, this is usually done during the loading process. For certain rather limited purposes, the shot retaining cup could be inserted without slitting. In general, however, it is provided with the slits 16.

Desirably, the upper cup is relatively thin at the top, for example, 0.015 to 0.020 of an inch at the open end 2 1. The wall may be as much as 0.25 to 0.30 of an inch at the elevation indicated at 25 in FIG. 3. The base or web portions 26 of the cup 15, however, is substantially thicker and is more on the order of thickness of the web in the overpowder wad 17. In other words, base 26 ranges from 0.062 to 0.068 of an inch thick.

The outside diameter of the shot cup or pouch as actually used very satisfactorily by the assignee of this invention, ranges from 0.005 to 0.018 of an inch larger than the largest inside diameter of the overpowder cup 17. Because of the curvature or outside radius of the cup at 25a in FIG. 3, cup 15 will enter the mouth 18 of the lower cup 17 and is frictionally held there near the mouth in the manner illustrated in FIG. 4. By the application of force the shot cup or pouch 15 can be forced further down into the overpowder wad 17 as shown in FIG, 5.

This type of action occurs whenever a shell shown in FIG. 6 is loaded and crimped closed. The hull or case, including tube 27, head 28, base wad 29, and primer 30 is fully assembled before it is loaded. After powder load 31 is placed in the hull or case, overpowder wad 17 is inserted into the hull and followed by the shot pouch or cup 15. After shot cup 15 is dropped into the hull, it is forced downwardly into cup 17 the desired distance by a ram. The shot 32 is next poured through the still open mouth of the hull. Thereafter, crimping tools engage the shell case mouth, first giving the indentations and then pushing the entire mouth down to form the crimped closure for the shell as seen at 34 in FIG. 6. Between the web 19 of the overpowder wad and the base or bottom 26 of the shot pouch or cup, is the air space or bubble 35. The closing force applied to the crimp 34 automatically assures that shot filled cup 15 remains telescoped into cup 17 the desired distance so that the hull is properly crimped over the edge 24 as illustrated in FIG. 6.

Variations in shot loads of the shell usually result in some alteration in the quantity of powder 31, or a variation in kind of powder, i.e., fast or slower burning, requires more or less space for the same shot load. The result in either case is a change in the amount of space within the hull 27 that is occupied by the shot and powder. If the wad column is expected to fill more space, then the pouch and wad are forced less far together by the ram. On the other hand, when a change in shot load, or powder load, or both, requires more space in the shell case or hull, the two parts of the wad column are forced more closely together as shown in FIG. 5. In the case of smaller loads the air bubble is much larger than is illustrated in FIG. 6. In the case of larger loads, the inner bubble is reduced to the size illustrated in FIG. 6 showing a maximum load. In no case, however, is there a total elimination of the air bubble 35 in the loaded shell. When the shell is fired, the inertia of the shot pellets in cup 15 cause it to tend to remain stationary until the overpowder wad 17 has been driven toward the cup 15 and the air bubble 35 is compressed sufficiently to begin to move the shot load. In this way air bubble 35 serves as a cushioning arrangement between the overpowder wad l7 and the shot pouch 15. For the smaller shot loads, the flexible ends 24 of the pouch cup 15 may be slightly turned over against the shot when the hull 27 is crimped as at 34.

It is possible under some circumstances that the pressure required to crimp the shell closed or for otherwise closing the shell demands greater resistance to telescoping of the nested type shot pouch and wad column illustrated in FIGS. l- 6 than can be achieved with the wedging and air bubble 35 as illustrated. When additional resistance elements are required, these may be incorporated either into the overpowder wad 17 or into the shot pouch wad 15. In FIG. 7, there is shown a modification in the overpowder wad. As shown there, the overpowder wad which is given a separate numeral 36 to distinguish it from the form previously described, is provided with the usual bottom web 37 and flange 38 as in the case of the overpowder wad 17. However, wad 36 also incorporates tapered buttress like projections at the inside of its walls as shown at 39 which projections increase in cross sectional dimensions as the web 37 is approached. This more rapidly increases the amount of resistance offered to telescoping of the shot pouch into the overpowder wad after the pouch reaches the tops of tapered projections 39.

FIG. 8 is a top plan view of the cup of FIG. 7 and here it can be seen clearly that there are four buttresses 39 arranged symmetrically around the wad. While four or more are preferred, the wad 36 can be manufactured with only three buttress elements 39 symmetrically spaced a greater angular distance around the inner wall of the wad 36.

FIG. 9 shows as alternative construction for a shot cup in accordance with the invention having additional support promoting greater reluctance or resistance to telescoping action. As illustrated in FIGS. 9 and 10, the bottom of the cup 41 is provided with a member 40 in the form ofa cross as best seen in FIG. 10. The four individual webs 40a-40d forming the cross 40 are sufficiently weak so that the force generated in loading the shell can cause partial collapse of these webs. On firing there is complete nesting of the cup for shot within the overpowder cup 17 or 36 as the case may be.

As is apparent, either type of overpowder wad can be combined with either type of shot cup shown and described herein. So may any two modified cups be nested together to produce between them the maximum resistance to telescoping beyond a certain point. Even with both the reinforced or buttressed overpowder wad and the web supported shot pouch or cup, however, firing produces sufficient force to cause total nesting or telescoping of the two units, one within the other. The type of shot cup or pouch shown in FIG. 9 may also be provided with slits or not as in the case of pouch 15.

In FIG. 11 there is shown still another embodiment of the shot cup or pouch which is numbered 45 to distinguish clearly from the two previous embodiments. The principal difference between this unit and those previously described is that it has a central cone 46 which is preferably hollow as shown herein. The cone is made hollow so as to maintain as light a weight as possible. The purpose of cone 46 is to produce a more rapid scattering of the shot once the shot pouch or cup is outside the barrel of the gun. Since the shot pouch or cup is often thought of as a shot concentrator and used to produce tighter patterns and longer ranges, the introduction of the cone 46 into this shot pouch 45 appears at first glance to be something of an anachronism. lnfact, however, shot

pouch

15 or 45 as the case may be is primarily for the purpose of preventing engagement between the walls of the gun barrel and the shot. This is for the dual purpose of preventing deformation of the shot and also the rubbing off of lead onto the barrel of the gun.

FIG. 12 shows the same shot cup as shown in FIG. 11 except that it is viewed from the top. Again cup 45 is seen to have a central cone 46 which will distribute the shot more widely and more quickly than if the pouch did not have the cone. In the structure shown in FIGS. 11 and 12, web portion 47 is comparable to the web portion of the other shot pouch embodiments. The thickness of the base or web 47 of the cup 45 should be about 0.065 inches with the walls of the shot cone 46 varying between 0.025 and 0.075 inches thick.

FIG. 13 illustrates the appearance of the type of wad column illustrated in FIG. ll after it has been fired from a gun. Note that the segments between slits I6 have a tendency to extend out away from the center of the unit. While they have recovered partially, they still show the effects of having been bent back by air pressure as the unit was fired whereby the segments act as an air brake."

The combined overall length of the wad column of the present invention when the cups are barely engaged as illustrated in FIG. 4 is approximately 1 7/16 inches for a 12 gauge shotgun shell. This can be reduced by about A of an inch, still leaving a substantial air cushion 35 as shown in FIGS. and 6. This A inch reduc tion or variation in size is ample to provide for all the variations encountered in one gauge of shell.

As can be seen in FIG. 6, when cup 115 is fully engaged in the overpowder wad, only the portion of the segments that extend above the edge of the overpowder wad 117 can bend to act as an air brake. For this reason, there is no particular merit in slitting the pouch to its bottom. On the other hand, there is no harm in slitting the pouch more deeply than the foregoing would suggest, providing the integrity of the air bubble 35 is not destroyed.

As can be seen from the above, this form of the invention provides a novel nested wad column which may be formed simply from two molded cups. These cups may be made to telescope to a greater or lesser extent in accordance with the shell load and are adjusted to the right length in an automatic manner by the time the end of the hull or tubular casing of the shell is crimped closed. The wad column allows the product of a pair of simple molds to be loaded in standard equipment for a large variety of loads. The need for a particular wad system for each load is eliminated and with it the need for several molds and several feed adjustments on a loader.

' Both cups have been made of a flexible and at least slightly resilient plastic such as a suitable polyethylene having a density in the neighborhood of 0.918 and a molecular weight in the neighborhood of 20,000. However, almost any polyolefin of any density and having molecular weight averages between 10,000 to 300,000 can be used for one or both of the cup wads of this invention.

FIGS. I l and I5 disclose another modification of the nested wad structure. Shot cup has a structure identical to that shown in FIG. 3. An overpowder wad cup is generally designated 50 to differentiate it from the modifications shown in earlier figures. Wad cup 50 has a short thick downwardly extending peripheral flange 511 connected to a web 52 which forms the bottom of the cup. Flange 511 and the bottom side of web 52 are adapted to immediately overlie the powder in a loaded shot shell. Wad cup 50 also contains a tubular center post 53 which has a thickness that decreases from a maximum at the point at which center post 53 meets web 52 to a minimum at the remote extremity of post 53. The remote extremity of post 53 has a first flattened or crimped section 54 and a second flattened or crimped section 55. These two flattened sections give the center post an elliptical annular cross section at each of the flattened areas with the major axes at the two ellipses at substantially right angles to one another. Flattened or crimped sections 54l and 55 provide a readily collapsible portion of center post 53 and provide a stable support platform for shot cup 15 to prevent it from tipping as it is pressed down onto center post 53. When shot cup is placed in contact with wad cup 50 as shown in FIG. I4, an air pocket 56 is formed inside of wad cup 50. Also, some air is trapped in the hollow center 57 of post 53. The air trapped in pockets 56 and 57 as well as tapered center post 53 cooperate to provide a custioned telescoping of cups 115 and 50 upon firing of a shell in which they are loaded.

Tapered center post 53 provides increasing resistance to increasing telescoping of shot cup I5 into wad cup 50 so that various loads can be accommodated, but sufficient resistance is provided so that the shell can be properly crimped closed over the load. In the modifications shown in FIGS. I4 and IS, the exterior diameter of shot cup 15 can be chosen to be: equal to, or slightly less than the interior diameter of wad cup 50. In that manner, telescoping of the two cup members can occur without excessively forcing the side wall of wad cup 50 outwardly. Such outward forcing causes undesirable bulges in the shell casing which are visible from the exterior. In the modification shown in FIGS. M and 15, the major resistance to telescoping is contributed by a center post 53 rather than by compression of air in pocket 56. This provides an advantage because it is much simpler to control the collapse of the center post than to achieve repeatable compressed air pressures in pocket 56. Also the tolerances of the diameters of cups I5 and 50 need not be controlled as tightly as in the embodiment shown in FIG. 4.

A further modification of the nested wad structure is shown in FIG. 16. The structure of shot cup 115 is identical to that shown in FIG. 3. The structure of the wad cup is substantially similar to that shown in FIG. 2, and is therefore numbered with'the same numbers as the parts in FIG. 2, but with primes added to indicate that it is a modified structure. The only significant difference appears at the upper exterior edge of cup 117'. At that point, the outside rim 23, is chamfered. Chamfered rim 23 is provided so that as shot cup 15 is forced into lower cup 17, forcing chamfered edge 23 outwardly slightly, edge 23 has no sharp edge to cause a pronounced ring shaped bulge in the shell casing as would the wad cup 17 shown in FIG. 2. Elimination of such a ring is desirable because it improves the exterior appearance of the shell, it reduces the possibility of some mid-portion of the shell catching in the gun chamber, and it reduces the likelihood of damage to the shell interior during firing. Such interior shell damage might cause difficulty in reloading shells.

FIGS. 17 through 211 illustrate the newly developed and presently preferred nested wad structure and the method of shell loading which utilizes that structure. The overpowder obturating wad portion is generally designated 60 and is shown separately in FIGS. I7 and t0. Wad 60 has a short, thick downwardly extending peripheral flange 611 and a circular web 62. Wad 60 also has a relatively low tubular side wall 63 which extends from web 62 in a direction opposite that of flange 6L An important feature of wad 60 is a tubular center post, generally designated 64 which extends upwardly from the center of web 62 in a direction opposite that of peripheral flange 61. Center post 64 has a thickness which tapers from a maximum immediately adjacent web 62 to a minimum at the extremity 65 remote from web 62. Center post 64 is adapted to be rolled back outwardly upon itself to form a platform upon which a shot cup sets. The amount of rollback is infinitely variable and is accomplished after wad 60 has been inserted into the shell case.

In order to obtain a wad 60 which is usable in all loads for a particular gauge shell, several dimensions have been determined to be important. The preferred height of the wad, from the bottom of flange 61 to remote extremity 65 of center post 64 is 1.050 inches, although it may be as little as 1.000 inches and as great as 1.200 inches. If the height of the wad is less than 1.000 inches it is not possible to load light loads such as a 3 dram-one ounce load. If the height exceeds 1.200 inches, the amount of roolback with heavy loads is so great as to interfere with the rollback formation because of doubling up of the rolled back material. The exterior diameter of center post 64 is preferred to be 0.310 inches although it may lie within the range from 0.250 inches to 0.450 inches. When the diameter is less than 0.250 inches there is an increased tendency for center post 64 to be pushed off center in loading thereby allowing the wad column to tip. When the post diameter is greater than 0.450 inches the rolled back portion interferes with the side of the wad when rolled back far enough for a heavy load. The preferred diameter is the best compromise between uniform load distribution and maximum stability against tipping.

Center post 64 is tapered in thickness, increasing toward the web, to prevent sudden collapse instead of a uniform progressive rollback.

The height of side wall 63 also contributes to the performance of wad 60. Preferred side wall height, from the bottom of flange 61 to the top of side wall 63 is 0.380 inches, although side wall heights as low as 0.175 inches and as great as 0.450 inches are workable. Side wall heights less than 0.175 inches allow wad 60 to tip excessively during the loading process and walls longer than 0.450 inches interfere with the bottom of the shot pouch on maximum loads.

Several materials are usable in manufacturing wads 60, although polyolefinic materials such as polyethylene are presently the most suitable. In general, theoverpowder wad must possess enough web strength between F. and 150 F. to prevent blow through or shattering when fired. It has been found that polyethylenes with a density greater than 0.925 grams/cc and a melt index of less than 3.0 are suitable for this purpose. The melt index referred to is determined according to 1964 ASTM Standard D1238-62T, Condition E. The presently preferred materials have a molecular weight. in the range of approximately 238,000-300,000, a melt index of not greater than 0.25, and a density of at least; 0.945 grams/cc.

The method of loading a shot shell with an overpowder wad 60 can best be described by reference to FIG.- 19. The rollback tool used in this method is shown in FIGS. 19 and 20. Referring now to FIG. 19, a cylindrical shell tube 70 is connected to a shell head 71 anda base wad 72. Inserted in a central aperture in shell head 71 is a battery cup 73 containing the primer. The basic shell casing structure may be any of a number of well known structures including those having paper tubes and those having plastic tubes. In FIG. 19, the shell is shown as having a plastic tube and a plastic base wad 72. Head 71 can be metal, as shown, or can be a plastic head integral with tube 70 and base wad 72. Shell tube 70 contains a powder charge 74 immediately above base wad 72. Immediately atop powder charge 74 is a rollback wad 60. Flanges 61 and the bottom of web 62 are in immediate contact with powder charge 74.

FIG. 19 shows the shot shell in an intermediate stage of loading. The loading machine is standard with one exception which is described below. As shown in FIG. 19, a powder charge has been placed in the shell and the overpowder wad 60 dropped in on top of the powder. At this point in the loading process, the shell tube 70 is confined within a shell receiving aperture 81 of a loading machine drum 80. Shell head 71 rests on a shell supporting plate 82. At the loading station shown in FIG. 19, a loading ram 83 is lowered into the mouth of tube 70 to seat wad 60 on powder charge 74 and to rollback upper extremity 65 of tapered post 64.

The structure of the lower face of ram 83 is shown in FIG. 20. The lower face consists of an outer annulus 84, a hemi-toroidal depression 85 and a central circular portion 86. These three portions of the lower face are constructed so that as the ram comes downward, the central portion fits into the interior of tubular post 64 and the hemi-toroidal depression rolls upper extremity 65 outwardly and downwardly back upon itself to form a support platform of a predetermined height above the top of powder charge 74.

Hemi-toroidal depression 85 in ram 83 has a profile which is adapted to roll upper extremity 65 back outwardly over an intermediate region 66 thereof while maintaining the maximum exterior diameter of the rolled back region not greater than the exterior diameter of tubular side wall portion 63. Preferably the rolled back portion is turned in such a manner that it forms a hollow ring which closes upon itself with the rolled back extremity 65 touching the outside of intermediate region 66. This condition, of course, does not occur when the lightest loads are used because the post is not rolled back a sufficient amount.

Loading ram 83 is spring loaded in a standard loading machine. The finished height of the wad is controlled by adjusting the effective length of ram 83 between the lower face and the point of attachment to the remainder of the machine. The effective length of ram 83 is infinitely adjustable. Such adjustability is achieved with any of a number of connecting means between ram 83 and the remainder of the machine, not shown. For example, ram 83 may be positioned in a cylindrical opening and held in position by tightening a screw bearing against the exterior of ram 83.

After overpowder wad 60 has been rolled back the proper amount, ram 83 is removed from tube 70, loading machine drum moves to the next station, and a shot cup is dropped in and seated atop rolled back post 64. The remaining loading steps are unchanged from standard loading procedures. That is, the shot cup is filled with shot and the end is crimped over the top of the filled shot cup to close the shell, making it ready for firing.

A cross section of a completed shell using the rollback nested wad configuration is shown in FIG. 21. The

shell casing structure is identical with that described with reference to FIG. 119. A slitted shot pouch 90 is positioned atop the rolled back portion of tubular center post 64. Shot cup 90, as shown, has a short thick downwardly extending flange 9ll which performs a secondary gas sealing function upon firing the shell. Flange 911 meets a circular web 92 which forms the bottom of shot cup 90. Downwardly extending flange 91 and web 92 cooperate with the platform formed by part of the rolled back region of tubular center post 64 to provide a stable wad column structure. Shot pouch 90 also has several longitudinal slits 93 extending from the open end of cup 90 toward web 92. Disposed within shot cup 90 is a shot load 94. Slits 93 are for the purpose of stripping shot cup 90 away from shot 94 as it leaves the barrel of the gun. Finally, the upper end of tube 70 is crimped down over the top of shot 94 at 95 to close the shell and retain shot 94 within it for storage purposes and loading into the gun. It should be noted that a flanged shot cup, such as cup 90, is not required with rollback wad 60 but it is preferred because of the stability of the combination. Shot cups like that shown in FIG. 3 can be used if desired.

In general, the support platform formed by the rolled back region of post 64 is made as large as possible without exceeding the interior diameter of the shell tube in which it is disposed or the interior diameter of flange 9i ifa shot cup like 90 of FIG. 21 is used. For example, in the case of 12 gauge shells using a flanged shot cup 90, the point of deepest recess above the lower surface of ram 93 in hemi-toroidal depression 95 lies on a circle having about a 0.392 inch diameter and the outside half of the recess is a circular arc with about a 0.125 inch radius. Therefore, when center post 64 is rolled back to its final position, the highest area of rolled back center post 64 lies on a circle having about a 0.392 inch diameter and the maximum diameter of the rolled back region is 0.642 t 0.003 inches. That maximum diameter normally is intermediate remote extremity 65 and intermediate region 66 except on the lightest loads.

Several things should be noted about the improved shell shown in FIG. 21. The shell is as it would appear with a maximum shot and powder load. That is, center post 64 is rolled back the maximum amount and very little space remains between the top of side wall 63 and the bottom of peripheral flange 91. Also, it can be seen that the rolled back extremity 69 curls back inwardly so that its inner surface contacts the exterior of intermediate region 66. Thus the exterior diameter of the rolled back region increases from remote extremity 65 to a point intermediate it and the juncture of the rolled back region with intermediate region 66, then decreases from the intermediate point to the juncture. This structure provides a good, broad support platform, provides increased strength and stability to prevent tipping of post 64, and helps to control the collapse of post 64 upon firing. It should be further noted that this modification of the nested wad structure does not re quire that tight tolerances be kept between the relative structure which may be used for all loads of aparticular ture which achieves a good force transfer from the burning powder and expanding gases to the shot thereby yielding pattern and shot string characteristics competitive with, or better than, prior wad structures utilizing more parts which demand greater inventory capability and more complicated loading procedures.

It is readily apparent that modifications may be made to rollback wad 60 without departing from the scope of the invention. For example, center post 64 can be con structed with an exterior diameter equal to, or slightly smaller than that of tubular side wall 63 and the rollback can be done inwardly rather than outwardly as shown.

Tests have shown that the patterns for nested wad type shells constructed in accordance with the present invention are superior. This is probably because of the better cushioning provided by the air bubble between

bases

26 and 19 as illustrated in FIG. 4 or by the collapsing post structures shown in FIG. 14 and FIG. 21. Patterns were tired under standard conditions, i.e., a 40 yard range with a full choked gun. Using the lighter and more efficient nested wads, more than adequate velocities with less variation was attained at standard pressures with a saving of two grains of powder per shell. Better patterns were also obtained].

Thus, the present invention provides an improved shot shell wad column that:

a. Is auto or self-adjusting in an infinite variety of a wide range of loads in standard shot shell cases.

b. Is easily molded from inexpensive material in simple inexpensive molds.

c. Is light in weight and consequently will contribute minimumally to recoil and has relatively short travel beyond the gun barrel.

d. Is fully effective in both sealing the combustion gases and cushioning the initial shock of firing in overcoming the inertia of the shot load.

e. And is substantially foolproof for use in either production or hand loading.

This invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the forc going description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What l claim is:

11. A method of loading shot shells which comprises: providing an empty primed shell casing; charging the 'casing with a predetermined amount of powder; seating an overpowder, obturating wad having an upwardly extending hollow post on top of the powder; rolling down the upper extremity of the hollow post by a predetermined amount; seating a shot cup on top of the rolled down wad post; loading a shot charge into the cup; and crimping an upper extremity of the case over the shot charge.

2. A wad column for use in shot shells loadable with a variety of powder and shot loads, the column comprising;

an obturating member;

a shot contacting member; and

spacing means, adjustable to an infinite variety of stable lengths by shell loading forces, for changing the overall length of the wad column sufficiently to accommodate all load variations in a single gauge of shell, and disposed between the shot contacting member and the obturating member, said spacing means comprising a permanently deformed projection having a base integral with the obturating member and having a remote extremity.

3. A wad column according to claim 2 wherein the shot contacting member is a shot protector cup having a bottom portion pressively engaging the projection.

4. A wad column according to claim 2 wherein the projection is hollow and has a thickness which decreases from the base to the remote extremity.

5.. A wad column according to claim 2 wherein the projection is tubular and has a rolled back region adjacent the remote extremity with the remote extremity disposed closer to the base than at least part of the projection connecting the extremity to the base.

6. A wad column according to claim 5 wherein the remote extremity tightly encircles an intermediate region of the projection and the exterior diameter of the deformed projection increases from the remote extremity to a juncture between the rolled back region and the intermediate region thereby providing a relatively' large stable support platform for the shot contacting member.

' 7. A wad for use in shot shells loadable with a variety of powder and shot loads, the wad comprising:

an obturating portion having a predetermined exterior diameter and adapted to lie between powder and shot charges; and permanently deformable projection means, integral with the obturating portion, for reducing the overall length of the wad to one of an infinate variety of stable lengths upon application of shell loading forces while maintaining the maximum dimension of the projection means in a direction parallel to the obturating portion no greater than the exterior diameter thereof.

8. A wad according to claim 7 wherein the projection means comprises a hollow tube having a wall thickness which decreases from one extremity integral with the obturating portion to an extremity remote from the obturating portion.

9. A wad according to claim 8 wherein the tube portion adjacent the remote extremity is rollable outwardly and downwardly toward the integral extremity.

I l). A wad according to claim 8 whereinthe obturating portion and the hollow tube are polyethylene having a melt index of less than 3.0 and a density greater than 0.925 grams/cc.

11. A shot shell comprising;

a shell case;

a powder charge in the case;

a wad according to claim 7 positioned in the case with the obturating portion immediately over the powder; I

a shot protector cup having a bottom contacting the projection means;

a shot load in the shot cup; and

closure means closing off the top of the case over the shot.

12. A wad column for use in shot shells loadable in a column with a variety of powder and a variety of shot loads, comprising:

a. a shot contacting member;

b. a separate cup-shaped obturating member opening towards said shot contacting member and having an annular flange extending outwardly therefrom and away from said shot contacting member; and

. compressible and permanently deformable tubular spacing means extending between said obturating member and said shot contacting member for changing the overall length of the wad column sufficiently to accommodate all load variations in a single gauge of shell;

d. said spacing means being formed of a compressible material and being constructed and arranged to be permanently compressible in its tubular portions by shell loading forces to an infinite variety of stable shorter lengths, including substantially shorter lengths, each of said shorter lengths being stable irrespective of whether said spacing means is in or out of a shot shell whereby in a loaded shell said shot contacting member and said obturating member are held apart by said means without any force tending to separate them further being exerted thereby.

13. A shot shell comprising;

a. a shell case;

b. a primer in said shell case;

0. a powder charge in said case adjacent said primer;

d. a shot load; 1

e. a compressible wad column separating said powder charge and said shot load;

s dsslumfiinssamsfis l. a shot contacting member,

2. a cup-shaped obturating member disposed over said powder charge and opening towards said shot contacting member and having an annular flange extending outwardly therefrom toward and around said powder charge, and

3. compressible tubular spacing means extending between said obturating means and said shot contacting member, said spacing means being compressed to one of an infinite number of degrees to accommodate the particular load of the shell and permanently deformed thereat, said means holding said shot contacting member and said obturating member apart without exerting thereon any force tending to separate them further, and

g. closure means closing off the top of the casing over the shot.

14. A wad column for use in shot shells loadable in a column with a variety of powder and a variety of shot loads, comprising:

a. an obturating member;

b. a shot contacting member; and

c. compressible and permanently deformable spacing means extending between said obturating member and said shot contacting member for changing the overall length of the wad column sufficiently to accommodate all load variations in a single gauge of shell;

d. said spacing means being formed of compressible material and being constructed and arranged to be permanently deformed by shell loading forces to an infinite variety of fixed stable shorter lengths, in-

cluding substantially shorter lengths, each of said shorter lengths being stable irrespective of whether 16. A method of loading shot shells which comprisesz a. providing an empty primed shell casing,

b. charging the casing with a predetermined amount of powder,

c. seating an overpowder, obturating member on top of the powder,

(1. seating a shot cup member above the obturating member in supported relation thereto,

e. rolling back by a predetermined amount the outer extremity of a hollow tubular element carried by one of the members and positioning the latter to extend the tubular element to the other member in support of the shot cup member,

I". loading a shot charge into the cup, and

g. crimping an upper extremity of the case over the shot charge.

17. A wad column for use in shot shells loadable in a column with a variety of shot loads, comprising:

a. a shot contacting member;

b. a separate cup-shaped obturating member opening toward said shot contacting member and having an annular flange extending outwardly therefrom and away from said shot contacting member;

c. each of said members having substantially cylindrical wall structure extending axially therefrom;

. compressible and permanently deformable spacing means other than said wall structure extending between said obturating member and said shot contacting member for changing the overall length of the wad column sufficiently to accommodate all load variations in a single gauge of shell; and

e. said spacing means being formed of a compressible material and being constructed and arranged to be permanently deformed and compressed in an axial direction relative to said members by shell loading forces to an infinite variety of fixed stable shorter lengths, including substantially shorter lengths, each of said shorter lengths being stable irrespective of whether said spacing means is in or out of a shot shell whereby in a loaded shell said shot contacting member and said obturating member are held apart by said means without any force tending to separate them further being exerted thereby.

18. The structure defined in claim 14 wherein said spacing means is carried by one of said members and extends toward the other of said members.

19. In a method of loading a shot shell which includes providing an empty primed shell casing; loading predetermined shot and powder charges in the casing; separating the shot and powder charges by a wad column within the casing; and closing off the top of the casing, the improvement comprising:

permanently deforming portions of said wad column after inserting at least part thereof in the shell casing before closing off the latter and thereby varying the overall length of the wad column to one of an infinite variety of fixed stable lengths, the length of said wad column resulting from such deformation being determined by the length of the particular predetermined charges while under shell loading forces within the shell casing.

20. In a method of loading a shot shell which includes providing an empty prime shell casing; loading predetermined shot and powder charges in the casing; separating the shot and powder charges by a wad column within the casing; and closing off the top of the casing, the improvement comprising:

permanently varying, after inserting at least part of the wad column in the shell casing and before closing off the shell casing, the overall length of the wad column to one of an infinite variety of fixed stable lengths, said wad column overall length being determined by the length of the particular predetermined charges while under shell loading forces within the shell casing, the overall wad column length being varied by permanently deforming a tubular projection on an overpowder wad, and then seating a shot cup in contact with the deformed projection.

i *l #l l

Claims

1. A method of loading shot shells which comprises: providing an empty primed shell casing; charging the casing with a predetermined amount of powder; seating an overpowder, obturating wad having an upwardly extending hollow post on top of the powder; rolling down the upper extremity of the hollow post by a predetermined amount; seating a shot cup on top of the rolled down wad post; loading a shot charge into the cup; and crimping an upper extremity of the case over the shot charge.

2. A wad column for use in shot shells loadable with a variety of powder and shot loads, the column comprising; an obturating member; a shot contacting member; and spacing means, adjustable to an infinite variety of stable lengths by shell loading forces, for changing the overall length of the wad column sufficiently to accommodate all load variations in a single gauge of shell, and disposed between the shot contacting member and the obturating member, said spacing means comprising a permanently deformed projection having a base integral with the obturating member and having a remote extremity.

3. compressible tubular spacing means extending between said obturating means and said shot contacting member, said spacing means being compressed to one of an infinite number of degrees to accommodate the particular load of the shell and permanently deformed thereat, said means holding said shot contacting member and said obturating member apart without exerting thereon any force tending to separate them further, and g. closure means closing off the top of the casing over the shot.

5. A wad column according to claim 2 wherein the projection is tubular and has a rolled back region adjacent the remote extremity with the remote extremity disposed closer to the base than at least part of the projection connecting the extremity to the base.

6. A wad column according to claim 5 wherein the remote extremity tightly encircles an intermediate region of the projection and the exterior diameter of the deformed projection increases from the remote extremity to a juncture between the rolled back region and the intermediate region thereby providing a relatively large stable support platform for the shot contacting member.

7. A wad for use in shot shells loadable with a variety of powder and shot loads, the wad comprising: an obturating portion having a predetermined exterior diameter and adapted to lie between powder and shot charges; and permanently deformable projection means, integral with the obturating portion, for reducing the overall length of the wad to one of an infinate variety of stable lengths upon application of shell loading forces while maintaining the maximum dimension of the projection means in a direction parallel to the obturating portion no greater than the exterior diameter thereof.

10. A wad according to claim 8 wherein the obturating portion and the hollow tube are polyethylene having a melt index of less than 3.0 and a density greater than 0.925 grams/cc.

11. A shot shell comprising; a shell case; a powder charge in the case; a wad according to claim 7 positioned in the case with the obturating portion immediately over the powder; a shot protector cup having a bottom coNtacting the projection means; a shot load in the shot cup; and closure means closing off the top of the case over the shot.

12. A wad column for use in shot shells loadable in a column with a variety of powder and a variety of shot loads, comprising: a. a shot contacting member; b. a separate cup-shaped obturating member opening towards said shot contacting member and having an annular flange extending outwardly therefrom and away from said shot contacting member; and c. compressible and permanently deformable tubular spacing means extending between said obturating member and said shot contacting member for changing the overall length of the wad column sufficiently to accommodate all load variations in a single gauge of shell; d. said spacing means being formed of a compressible material and being constructed and arranged to be permanently compressible in its tubular portions by shell loading forces to an infinite variety of stable shorter lengths, including substantially shorter lengths, each of said shorter lengths being stable irrespective of whether said spacing means is in or out of a shot shell whereby in a loaded shell said shot contacting member and said obturating member are held apart by said means without any force tending to separate them further being exerted thereby.

13. A shot shell comprising; a. a shell case; b. a primer in said shell case; c. a powder charge in said case adjacent said primer; d. a shot load; e. a compressible wad column separating said powder charge and said shot load; f. said wad column being comprised of;

14. A wad column for use in shot shells loadable in a column with a variety of powder and a variety of shot loads, comprising: a. an obturating member; b. a shot contacting member; and c. compressible and permanently deformable spacing means extending between said obturating member and said shot contacting member for changing the overall length of the wad column sufficiently to accommodate all load variations in a single gauge of shell; d. said spacing means being formed of compressible material and being constructed and arranged to be permanently deformed by shell loading forces to an infinite variety of fixed stable shorter lengths, including substantially shorter lengths, each of said shorter lengths being stable irrespective of whether said spacing means is in or out of a shot shell whereby in a loaded shell said shot contacting member and said obturating member are held apart by said means without any force tending to separate them further being exerted thereby.

15. The structure defined in claim 14 wherein said spacing means is constructed and arranged to provide a range of variation in length of the wad column ranging up to 1/4 inches.

16. A method of loading shot shells which comprises: a. providing an empty primed shell casing, b. charging the casing with a predetermined amount of powder, c. seating an overpowder, obturating member on top of the powder, d. seating a shot cup member above the obturating member in supported relation thereto, e. rolling back by a predetermined amount the outer extremity of a hollow tubular element carried by one of the members and positiOning the latter to extend the tubular element to the other member in support of the shot cup member, f. loading a shot charge into the cup, and g. crimping an upper extremity of the case over the shot charge.

17. A wad column for use in shot shells loadable in a column with a variety of shot loads, comprising: a. a shot contacting member; b. a separate cup-shaped obturating member opening toward said shot contacting member and having an annular flange extending outwardly therefrom and away from said shot contacting member; c. each of said members having substantially cylindrical wall structure extending axially therefrom; d. compressible and permanently deformable spacing means other than said wall structure extending between said obturating member and said shot contacting member for changing the overall length of the wad column sufficiently to accommodate all load variations in a single gauge of shell; and e. said spacing means being formed of a compressible material and being constructed and arranged to be permanently deformed and compressed in an axial direction relative to said members by shell loading forces to an infinite variety of fixed stable shorter lengths, including substantially shorter lengths, each of said shorter lengths being stable irrespective of whether said spacing means is in or out of a shot shell whereby in a loaded shell said shot contacting member and said obturating member are held apart by said means without any force tending to separate them further being exerted thereby.

19. In a method of loading a shot shell which includes providing an empty primed shell casing; loading predetermined shot and powder charges in the casing; separating the shot and powder charges by a wad column within the casing; and closing off the top of the casing, the improvement comprising: permanently deforming portions of said wad column after inserting at least part thereof in the shell casing before closing off the latter and thereby varying the overall length of the wad column to one of an infinite variety of fixed stable lengths, the length of said wad column resulting from such deformation being determined by the length of the particular predetermined charges while under shell loading forces within the shell casing.

20. In a method of loading a shot shell which includes providing an empty prime shell casing; loading predetermined shot and powder charges in the casing; separating the shot and powder charges by a wad column within the casing; and closing off the top of the casing, the improvement comprising: permanently varying, after inserting at least part of the wad column in the shell casing and before closing off the shell casing, the overall length of the wad column to one of an infinite variety of fixed stable lengths, said wad column overall length being determined by the length of the particular predetermined charges while under shell loading forces within the shell casing, the overall wad column length being varied by permanently deforming a tubular projection on an overpowder wad, and then seating a shot cup in contact with the deformed projection.