US2002960A - Priming mixture - Google Patents

Description

Patented May 28, 1935 PATENT OFFICE PRIMING mxruan Joseph D. McNutt, New Haven, Coma, assignor to Winchester Repeating Arms Company, New Haven, Conn., a corporation of Maryland I No Drawing. Application November 18, 1933,

Serial N0. 698,688

6 Claims.

.This invention relates to priming mixtures for small arms ammunition and more particularly to a non-mercuric priming mixture.

Heretofore mercury fulminate has been generally used as the initiator in priming mixtures for small arms ammunition. It possesses many advantages and it has been difllcult to find other materials to be used in place of mercury fulminate which wouldproduce as satisfactory results,

' even though considerable efiorthas been made to eliminate mercury fulminate from priming mixtures. While it possesses certain advantages, it also possesses certain disadvantages. Amalgamation of the cartridge cases caused by the free mercury produced by the decomposition of the mercury fulminate when the cartridge is exploded prevents reloading of center fire cartridges. By employing a priming mixture in which no mercury fulminate is present, this' sesses advantages for use in rim fire primers. It

has greater stability on storing and therefore permits the ammunition to be used and better results obtained after it has been stored for long periodsof time.

In the present invention I employ an initiator consisting of basic lead trinitroresorcinol and lead dinitrophenylazide. The lead dinitrophenylazide may be prepared by the method disclosed in my prior Patent No. 1,906,394, granted May 2, 1933. The basic lead trinitroresorcinolmay be prepared by the method disclosed in the Tauson application, Serial No. 690,777, filed September 23, 1933.

I am aware that normal lead trinitroresorcinol has been proposed for use as an'ingredient of priming mixtures for small arms ammunition. So far as I know, basic lead trinitroresorcinol has not been used in priming mixtures for small arms ammunition because of its relatively low sensitivity. It is, of course, less hazardous to manufacture basic lead trinitroresorcinol than normal lead trinitroresorcinol because of its lower sensitivlty;

I have found that basic lead trinitroresorcinol may be used in combination with lead dinitrophenylazide as the initiator of a priming mixture, in certain proportions, without materially impairing the sensitivity of the lead dinitrophenylazide. At the same time, it produces an improved priming mixture because of the greater density of basic lead trinitroresorcinol. The density of lead dinitrophenylazide is so low that dimculties in loading the priming mixture into primer cups or cartridge cases would be encountered if it were used alone as the initiator. By mixing it in certain proportions with' basic lead trinitroresorcinol a more workable density is obtained and at the same time thesensitivity of the priming mixture approximates the sensitivity that would result if lead dinitrophenylazide were used alone. I

In carrying out my invention the combination 10. of initiators set forth above may be used with the common oxidizers, fuels and abrasives. As examples of priming mixtures which I have found satisfactory I may prepare a priming mixture for rim fire ammunition by mixing the foll lowing ingredients in substantially the following proportions:

' Percent Basic-lead trinitroresorcinol 2'7 Lead dinitrophenylazide 13 Double salt of barium and potassium nitrate" Antimony sulphide e 7 Ground glass 23 Likewise, a center fire mixture may be pre- Double salt of barium and potassium nitrate" 40 30 A imony sulphide 23 Calcium silir'ide 7 The proportions of these ingredients may, of course, be varied depending upon the commercial strength of the ingredients and to meet the requirements of various uses of the mixtures. Likewise, known equivalents may be substitutedfor the oxygen supplying elements and fuels without departing from the spirit of the invention. As an 40 example, barium nitrate may be substituted for the double salt of barium and potassium nitrate given in the formula, the quantity of barium nitrate to be employed varying slightly from the quantity of the double salt of barium and potassium nitrate given above to obtain substantially the same qualities in the resulting mixtures.

The rim fire mixture is prepared in the usual way, poured into individual pellets of the proper size for the individual charges by means of a charge plate in the usual manner and then translferred to empty rim fire cartridge shells. The priming mixture is then forced to distribute itself in the hollow rim of the cartridge shell by spinning the shell in the customary machine.

the priming mixture set forth above, the ingredients are first thoroughly and homogeneously mixed. The mixture is then poured into individual pellets of the proper size for the individual charges in the customary way by means of a charge plate provided with perforations adapted to mold pellets of the proper size. These pellets are then loaded into primer cups in the usual way and the primer cups then assembled in. the cartridge cases.

I claim:

1. A priming mixture comprising basic lead trinitroresorcinol and lead dinitrophenylazide.

2. A priming mixture comprising basic lead trinitroresorcinol, lead dinitrophenylazide and the double salt of barium and potassium nitrate.

3. A priming mixture comprising basic lead trinitroresorcinol, lead dinitrophenylazide, the

double salt of barium and potassium nitrate and antimony sulphide.

4. A priming mixture comprising basic lead trinitroresorcinol, lead dinitrophenylazide, the double salt of barium and potassium nitrate, antimony sulphide and calcium silicide.

5. A priming mixture comprising basic lead trinitroresorcinol substantially 27 percent, lead dinitrophenylazide substantially I 13 percent, double salt of barium and potassium nitrate substantially 30 percent, antimony sulphide substantially '7 percent and ground glass substantially 23 percent.

6. A priming mixture comprising basic lead trinitroresorcinol substantially 22 percent, lead dinitrophenylazide substantially 8 percent, double salt of barium and potassium nitrate substantially 40 percent, antimony sulphide substantially 23 percent and calcium silicide substantially 7 percent.

JOSEPH D. McNU'I'I.