US2076868A - Ammunition - Google Patents

Description

- Patented Apr. 13, 1937 UNITED STATES PATENT OFFICE Conn, a corporation of Maryland No Drawing. Application December- 29, 1933,

Serial No. 704,512

18 Claims. C1. 102-31) J This invention relates to ammunition and more particularly to a lubricating projectile or sing for use in the manufacture of cartridges for small arms. 1

6 In the use of cartridges having bullets formed of lead or lead. alloys it is necessary to provide some means to prevent metal fouling of the gun barrel. Unless some precaution is taken the bullets, when projected through the barrel, build up 10 a coating of lead in the interior of the barrel.

This coating interferes -with the ballistics of the gun and requires vigorous'use of a wire brush to remove it. 1 p The simplest expedient, for overcoming this 15 difl'iculty is to lubricate the exterior of the bullets with grease. This practice is still employed in connection with ammunitionwhere the greatest accuracy is required. No other method of overcoming metal ,foulingof the gun barrel has yet been deyise which provides the accuracy of the greased bullet. It, however, is subject to the disadvantages that the cartridges are greasy and are therefore unpleasant to handle.

Another means of preventing metal fouling of A 25 the gun barrel is toelectro-plate the exterior of a bullet with. another metal, such as copper. Plated bullets are also open to objection, where the greatest accuracy is desired, because they have never attained the accuracy of the greased 30 bullet. Plated bullets are also more expensive than the unplated bullet. r

The present invention comprises a projectile or of the lubricant is normally present on the outside of the bullet so that the bullet can be handled without the grease or lubrication coming off, but under the influence 'of heat or pressure the lubricant exudes or oozes out to the surface. When the bullet is passing through the gun bar 40 rel, the heat and pressure created causes the oil to come to the surface of the bullet and it, therefore, satisfactorily performs its. function in lubricating the barrel. I am aware that it has been proposed to provide' metal for use in bearings and 45 the like containing a lubricant in the interior of the metal which will exude to the surface upon the application of heat and pressure. Such bearing metals are formed from finely divided metal under high pressure producing a more -or less 50 porous product. The metal is then heated and plunged into cold oil. The cooling of the metal to the temperature of the oildraws the oil into the pores of the metals. Such a process, however, can 7 i not be applied to the manufacture of projectiles or bullets formed of lead or lead alloys. The

siderably lower temperature. being taken up by the pores or voids and due plastic nature-oi lead prevents the application of this process to the manufacture of lead bullets. I have ound that lead or'lead alloys from which projectiles-or bullets are to be formed can be conditioned to take up suiiicient'oil in the-in terior of the bullet or slug by adding a small amount of adry powdered substance which is convertible into a gas at a temperature below the melting point of lead. In this way a lead product is obtained which will retain all the desirable characteristics for use as a projectile or bullet, but at the same time it will have the property of taking up oil in its interior and releasing the oil upon the application of heat or pressure. Various substances can be used for this purpose. As examples, sawdust, naphthalene, ammonium carbonate and the like, may be employed. The

. -least amount that will properly function and 7 under some conditions less than .5% may beused.

In forming the projectiles, the dry powdery substance. which is convertible into a gas at a temperature below the melting point of lead is added, in the proper amount, to finely divided lead. It is mixed with the lead to form a homogeneous mixture. When the material is to be extruded into a wire for the'formation of slugs, a small amount of alubricant is added to the mixture. This mixture is then extruded through a die into a wire or rod of the proper size. The 35 wire is cut into slugs and the slugs swaged into bullet form. The bullets are heated to a temperature below the melting point of lead but high enough to convert the powdered material into a gas. The gas thus formed is expelled, leaving the bullet in a porous condition. While heated. the bullets are dropped into lubricating oil at a con- This results in oil throughout the bullet'by capillary actionand by the partial vacuum formed when theheatedbullet is cooled by the body of oil. The exact procedure as outlined above may be altered. The slugs may be heated and placed in the oil before swaging and then swaged after they have been removed from the oil and the excess oil removed from the surface of the slugs. As a further alternative procedure, the extruding step 'may be eliminated and the bullets may be swaged to form directly from the powdered mixture and then submitted to the oil impregnating treatment.

As set forth above, the addition of a powdery substance that will be converted into a gas at a lower temperature than the melting point of lead to lead or lead alloys which are to be used in the manufacture of projectiles or bullets produces a material that retains the desirable characteristics of lead for use in bullet manufacture but at the same time permits a lubricant to be taken up by the metal in the mannerset forth above. This produces a bullet or slug that is free from any oil on its exterior so that the cartridges may be handled without soiling the hands or clothing but upon the application of heat or pressure the oil seeps to the surface of the bullet and therefore properly lubricates the barrel when the bullet is passing through it.

I claim:

1. A projectile for small arms ammunition comprising a lead slug having lubricating oil distributed substantially uniformly throughout the slug.

2. A projectile for small arms ammunition comprising a slug formed of a mixture of lead'and a powdered material that gasifies at a temperature below the melting point of lead.

3. A projectile for small arms ammunition comprising a slug formed of a mixture of lead and naphthalene.

4. A projectile for small arms ammunition comprising a slug formed of a mixture of lead and ammonium carbonate.

5. The process which comprises forming a mixture of lead and a powdered material that gasifies at a temperature below the melting point of lead,

6. The process which comprises forming a mix-' ture of lead and a powdered material that gasifies at a temperature below the melting point of lead, extruding the mixture through a die to form arod, cutting the rod into slugs, heating the slugs,

5 and immersing the heated slugs in oil at a tem- 'perature below the temperature of the slugs.

'7. The process which comprises forming a mixture of lead and saw-dust, compacting'the mixture to form a substantially solid metal product,

50 heating the product and immersing the' heated product in a body of oil at a lower temperature than the temperature of the product.

8. The process which comprises forming a mixture of lead and sawdust, extruding the mixture -through a die to form arod, cutting the rod into slugs, heating the slugs, and immersing the heated slugs in oil at a temperature below the temperature of the slugs.

9. The process which comprises forming a mixture of lead and naphthalene, compacting the mixture to form a substantially solid metal product, heating the product, and immersing the heated product in a body of oil at a lower temperature than the temperature of the product.

10. The process which comprises forming -a mixture-of lead and naphthalene, extruding the mixture through a die to form a rod, cutting the rod into slugs, heating the sings, and immersing the heated sings in oil ata temperature below the temperature of the slugs.

11. The process which comprises forming a mixture of lead and ammonium carbonate, compacting the mixture to form a substantially solid metal product, heating the product, and immersing the heated product in a body of oil at a lower temperature than the temperature of the product.

12. The process which comprises forming a mixture of lead and ammonium carbonate, extruding the mixture through a die to form a rod, cutting the rod into slugs, heating the slugs, and immersing the heated slugs in oil at a temperature below the temperature of the slugs.

13. A projectile for small arms ammunition comprising a lead slug having pores distributed substantially uniformly throughout said slug and a lubricant in said pores. I

14. The process which comprises forming a mixture of lead and a powdered material that gasifies at a temperature below the melting point of lead, compacting the mixture to form a substantially solid metal product, and then heating theproduct. x

15. A projectile for small arms ammunition comprising a bullet formed by heating a mixture of lead and a powdered material that gasifies at a temperature below the melting point of lead to gasify said material and form pores throughout the bullet, and a lubricant distributed throughout said pores.

16. A projectile for small arms ammunition comprising a bullet formed by heating a mixture of lead and sawdust to a temperature sufiicient to gasif the sawdust and form pores throughout the lead bullet, and a lubricant distributed throughout said pores.

17. A projectile for small arms ammunition comprising a bullet formed by heating a mixture of lead and naphthalene to a temperature sufficient to gasify said naphthalene and form pores throughoutothe lead bullet, and a lubricant distributed throughout said pores.

18. A projectile for small arms ammunition comprising a bullet formed by heating a mixture of lead and ammonium carbonate to a temperature sufiicient to gasify said ammonium carbonate and form pores throughout the lead bullet, and a lubricant distributed throughout said pores.

PHILIP A. SMITH.

CERTIFICATE OF CORRECTION. Patent No. 2,076,868. April 13, 1937.

PHILIP A. SMITH.

It is hereby certified that error appears in the printed specification of the above numbered patent vrequiring correction as follows: Page 1, second column, "line 4'7, after oil insert the Words I preferably employ a light mineral oil althcugh other kinds of oil may be used. I The bullets are removed from the oil and the excess oil removed. This can be done by rumbling in sawdust or by centrifuging. If the size or the shape of the bullet has been chan ed by the oil treatment, the bullets may again be swaged. and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office. I

Signed and sealed this 8th day of June, A. D. 1937.

Henry Van Arsdale (Seal) Actin Commissioner of Patents.

CERTIFICATE OF CORRECTION. Patent No. 2,076,868. April 15, 1937.

PHILIP A. SMITH.

. It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, second column, line 47, after "oil insert the words I preferably employ a light mineral oil, although other kinds of oil may be used. I The bullets are removed from oil and the excess oil removed. This can be done by rumbling in sawdust or by centrifuging. If the size or the shape of the bullet has been changed by the oil treatment, the bullets may again be swaged. and that the said. Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office. y

Signed and sealed this 8th day of June, A. D. 1957.

Henry Van Arsdale (Seal) v Acting Commissioner of Patents.