Small Pistol Primer

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Effect of carcless seating of primers, and use of primers in wrong case or pocket. Left, Remington primer carelessly seated in Remington primer pocket, thus distorting anvil and crumpling charge. Notice how paper disc has buckled and the pellet mixture has broken beneath it. Right: Remington primer seated in Winchester primer pocket. Note crimping effcct of Winchester pocket on this primer. Distortion of the pellet and paper disc is certain to result in faulty ignition the hammer and struck it down a wide conical touch-hole communicating with the chamber. In 1818, Manton developed a slender copper tube about the diameter of a match stick and half-an-inch long, said tube being filled with fulminate. This was laid lengthwise in a horizontal vent in the barrel where it was struck by the hammer, the explosion igniting the charge and usually blowing away the tube. Other copper-cap ideas occasionally necessitated the operator to scrapc the mutilated cap from the nipple. The Manton idea was used in the famous Merrill guns, of which more than 14,500 were bought by the British Government during that period.

In 1823, the American physician, Dr. Samuel Guthrie, hit upon the unique idea of rolling the fulminate into little pills or pellets which were dropped into a cup 011 the lock, where they were struck by the hammer, transmitting the flash through the tube or nipple to the charge. For several years these were widely manufactured, and many government and sporting arms were constructed to use r^em. These pills, although origi nated 111 this country by Guthrie, were introduced by an unknown inventor 111 England, and in 1821 Westley Richards produced high-grade arms with a lock capable of using all the new forms of ignition, such as loose detonating powder, paper caps or pills. Arms using pills were made as late as 1851, of which the curious and now rare Porter wheel-chamber repeating rifles and revolvers are an example.

The Percussion Cap. Who, therefore, invented the percussion cap? Great Britain heads the list with claimants as follows: Hawker, Manton, Durrs Egg (one of the eleven of the Egg family of gunsmiths between 1750 and 1880), lloantree, Lancaster, Lang and Westley Richards. France and Switzerland claim it for the Swiss Parisian, Captain Pauly, and for Baron Heurtcloupe. Belgium and Germany also have long lists.

In 1825, in the fifth edition of his Instructions to Young Sportsmen, Captain Peter Hawker, the famous British sportsman, naively comments that he "docs not say" that he "was the inventor of the copper cap," but only that in 1818 the idea of a "perforated nipple" and detonating powder in the crown of a small cap occurrcd to him, and he thereupon suggested it to Joe Manton, who made such caps. Note the date. This was at least four years alter such caps were already in use in America. Even Greener of England gives credit to the United States for this development and takes his hat off to Joshua Shaw, a British-born but Americanized artist and sportsman.

Joshua Shaw was born in Belingeborough, Lincolnshire, in 1776, and in 1814 settled in Borden-town, New Jersey, soon removing to Philadelphia, where he lived until his death in i860. He made his name as an artist before coming to Amcrica. The best account of his invention states that Shaw first had the copper-cap idea before he left England but kept his discovery secret until he arrived in America. (Sec "Origin of Breech-Loading Firearms," by Capt. Philip Reed, 3rd Infantry, U.S.V., published in The Army Magazine, Chicago, April 1894.) Soon after arriving in the United States he applied for a patent, which was refused him on the ground of his being an alien; the law at that time denying a patent to aliens unless they had resided two years in this country. This was Shaw's own statement. In 1814 he made percussion caps with steel cups, changing to pewter in 1815 and to copper in 1816. England copied some of his caps as late as 1820 by using thin tinned iron. In 1822 he patented a lock action to use his caps.

Shaw had used fx>tassium chlorate, but, as he wrote, this was "too sensitive and liable to acci dental explosions," and so a mixture of fulminate of mercury, chlorate of potash and powdered glass was finally employed. In 1846, at the age of seventy years, on special recommendation of the Government's Congressional Committee of Patents, Shaw was awarded an honorarium of $25,000 for his discovery and improvements. It is a matter of record that petty politicians stepped in and effected a reduction of this sum to $17,000.

In 1828, Charles Eley, who founded the famous British ammunition firm of this name, was blown to pieces in handling priming composition in his shop. Shortly thereafter the British Government stepped in and regulated by law both the method >f manufacture and the formula to eliminate accidents.

In the United States, between 1812 and 1825, seventy-two patents were issued to American inventors for various forms of primers. The May-nard tape primer described in Chapter III was one of the most satisfactory of the entire line, although it came out during a time when the copper cap was thoroughly established. The famous Sharps rifles were made from 1848 to 1852 with a Maynard primer magazine on both military and hunting weapons. In 1855 the British Government contracted with Christian Sharps for 6500 .52-caliber carbines designed for the Sharps linen cartridge with Maynard tape primer magazines. This despite the fact that the Sharps arms were, from the first, put out in the common nipple-and-cap ignition system. Chapter III gives still further information on these developments. Percussion caps were in such demand throughout the Civil War, that Southern spies were sent into the North and instructed to obtain, at any price, large quantities of caps which they secretcd on their persons and smuggled back into the Confederacy.

Even today laws regulate the manufacture of primers in some countries. The latest (1929) edition of the British Tcxtboo\ of Small Arms, on pages 233 to 235, gives a digest of the formula and manufacturing methods established by law.

Some day a worthy historian will record the true facts of the primer, and in doing so he will write an entire book on the subject. Nothing short of a full volume would do this tremendous subject full justice.

The Centerfire Cartridge. With the modern centerfirc cartridge came the true beginning of the handloading era. All manufacturers of ammunition sold not only factory loads bur also all components from cartridge cases to primers and bullets. The cartridge case was at that time of folded-head construction, although the solid-head type followed along shortly thereafter. In addition, the Ideal Manufacturing Company brought out a line of "Everlasting' shells which were not only made in solid head our also of much sturdier brass. With standard .38/55 empty cases selling at about $1.80

Guide Handloading

Method of removing primers from cartridge cases where it is desired to analyze them for photographs. Punching the primers out would mutilate the pellet. Shell is chucked in a lathe and the head turned off as in figures 2 and 3 so the primers can be picked out with the fingers. The method used on such shells as figure 4 of the old foldcd-hcad type is to saw through the head as illustrated in figure 5. Anvils are removed by means of special cutters as in figure 6. This is extremely dangerous without proper equipment, and must not be attempted by a handloader. Figure 7 shows a primer which has been sawed in half. These and other micro-photos in this chapter were taken by Professor E. M.

Chamot of Cornell University

Method of removing primers from cartridge cases where it is desired to analyze them for photographs. Punching the primers out would mutilate the pellet. Shell is chucked in a lathe and the head turned off as in figures 2 and 3 so the primers can be picked out with the fingers. The method used on such shells as figure 4 of the old foldcd-hcad type is to saw through the head as illustrated in figure 5. Anvils are removed by means of special cutters as in figure 6. This is extremely dangerous without proper equipment, and must not be attempted by a handloader. Figure 7 shows a primer which has been sawed in half. These and other micro-photos in this chapter were taken by Professor E. M.

Chamot of Cornell University per hundred, the Ideal "Everlasting" cases were priced at six cents each—three times as much. They did have a great deal longer life and were much in demand by reloaders. "Everlasting" shells, because of their stiff brass and thicker walls, did not hold as great a charge of powder and could not be crimped, the latter point eliminating them from practical use in repeating rifles.

And so wc get to the period of the 1890^. Up to this time, metallic ammunition and handloading had, generally speaking, meant exclusive use of black powder; therefore the primers had been a fulminate-of-mercury cap designed to ignite black powder efficiently. In the early (jo's, when smokeless powder entered the scene, ignition troubles were immediately noticed, as the black-powder

Perfect example of what careless primer seating can do. Primer on the left was slammed home in a slipshod manner. Note the distortion of the anvil. On the right is seen the same primer with paper disc and anvil removed. Notice liow die primer pellet is broken up. This primer would give extremely faulty ignition, possibly a misfire or hangfire primer was insufficiently "hot" to ignite the new propellent. Accordingly, ammunition manufacturers set to work on the problem and designed a primer sufficiently strong to ignite the smokeless. They still manufactured the black-powder primer, which was widely sold up to about the time of the

Inspect your primer; carefully. At the left is a primer which has been discharged but failed to burn up the paper disc. On the right is a primer just as it was removed from the box. Note the very fine excelsior crimped between the anvil and the primer cup. Inspectors don't always catch these flaws. It will do you no harm to inspect primers for match ammunition beneath a magnifying glass

World War, despite the fact that the smokeless primer performed as efficiently with black powder as the old primer. Smokeless primers immediately brought forth a great many problems which hitherto had gone unnoticed among the handloading claa

Magazines and catalogs of about the 1900 period waxed loud in their discussions of the good and bad points of various smokeless powders and the problems crcatcd by their use. By 1905 there were two distinct types of smokeless powder available to handloaders—the bulk and the dense. The former was known as low-pressure; the dense powders were classed as high-pressure, in the former we had such powders as Du Pont $1 and #2 rille, Bulk Shotgun, Oriental. King Smokeless, £1, $2, J 3 and #4, E. C., Schultz, and so forth.

In the same dense-powder family was the Laflin ¿c Rand, Lightning, Sharpshooter, Unique. Infallible, W.A., Du Pont .30-Caliber Annular Government, and so forth, in the Du Pont tribe, and a number of German importations widely sold on

Cross-sect ions of live primers. Figure 1 shows a tipped anvil. Inspection would disclose this. Do not attempt to use it. Figure 2, extremely irregular poor-quality priming mixture, not properly distributed through the cup. Figure 3, cross-sections of a primer which started to decompose. This was located in examining a batch of defective primers. Note cloudy white color of priming mixture below anvil. Figure 4, a Berdan primer, cross-section. Note that primer pellet is slightly compressed in the cup. Disc o£ tinfoil over the pellet may be seen the American market. Both types were occasionally used by handloaders with black-powder primers, when a small priming charge of black powder was first inserted into the bottom of the shell.

Primers available in 1900 included the UMC r'O," adapted to UMC shells only; and the UMC #1» 11/4, 6, 6l/z and the corresponding sizes in Winchester to fit the same pockets bearing the numbers 1, iW, il/lf UMC primers #2, iiVzy #7, #7Vi would interchange with Winchester J2, and #3. UMC primer <8Vi was also the same size as Winchester 85. The Bcrdan-type primer was also sold (still available on special order). These were made by both UMC and Winchester bearing numbers 1, \}/i and 2; $1 only for sporting and military cartridges; iiVi for brass shot shells and #2 used for small rifle and handgun

Mvroptiotos by K. M. Charit at

Small Pistol Primer Mixture

\iivrvjihol<jb by E. If. Chamot

JJ icrophoto* by E. M. Chu mot cartridges. Winchestei and UMC }i were both made of brass drawn to a heavier cup than the black-powder copper-cup primers adapted to the black-powder load. Number iV2 Winchester was

ilivroitholos by E. M. Ghnmot

More primer abnormalities, l'hese illustrations also show clearly the difference between Remington and Winchester types of construction. Figures 1, 2, 3 arc Winchester products in which the primer is seated on the anvil at the bottom of the primer pocket. The others arc of Remington type, in which the primer is supposed to seat on the mouth of the cup rather than on the anvil itself. In figure 1 note cocked angle. In figure 2 note uneven sides to the cup. In figure 3 one side of the cup is much bigger than the other. Figure 4 shows a slightly cocked angle. Figure 5, a normal primer. Figure 6, poor quality of pellet improperly inserted and anvil improperly punched and projecting too far out of cup; this primer is quite likely to explode when being seated. Figure 7, insufficient and poor quality of pellet. Figure 8, improperly shaped anvil projecting too far out of case, coupled with insufficient and poor quality of pellet low-pressure rifle cartridges running from .22 WCF up to .45/70; the Jfi/a UMC and fiW Winchester were adapted to the similar line of cartridges, but for smokeless powders, and were the same size as $1 Winchester but designed £01 black-powder revolver cartridges, while iil/2\\\ also a copjxrr primer, was designed for smokeless powders. List price on primers in 1900 was $1.70

per thousand for the Berdan type and $2.00 per thousand for all others.

Smokeless Powder Problems. In the late 1890's, some of the ammunition makers who had for years sold components to reloaders and advocated reloading, began to publish notes on their smokeless to set two or three days, clean or unclean, wet or dry, loaded or unloaded . . . the metal becomes brittle and rupture of the shells at the next discharge is probable. Various proportions and kinds of material used in the manufacture of the brass have been tried. . . . Chemists have examined

Miaropkotos by E. M. Ch-tonot

Fitting primers to pockets. Figure 1 shows a normal Remington primer. Figure 2, a Winchester primer with anvil slightly cockcd. Figure 3 shows a Remington shell head and cross-section. Figure 4 is one of Winchester's make. Incidentally, in this particular shell the primer was crimpcd and one may sec the crimping groove. Note the difference in primer-pocket shapes at A and C. Figure 5, a Remington primer fired in a Remington primer pocket. Figure 6, Remington primer fired in Winchester pocket powder shell boxes, saying: "These shells cannot be reloaded." At about this time, Winchester released a circular entitled, "Reloading Smokeless Powder Cartridges Impracticable." The chief remark of importance in these circulars, as we look back at them, was just this: "All smokeless powders arc injurious to brass shells. . . . Experiment shows that after the first firing with smokeless powder, the metal of the shell undergoes a slow but decided change, the exact nature of which the best experts have as yet failed to determine. No immediate deterioration attends the using of smokeless powder. . , . If fired shells are allowed shells before and after firing to determine the exact corrosive effect of the gases. . . . Experiments show that these problems arc characteristic of all smokeless powders and are in no way due to the material used in the shells, the proccss of manufacture or the kind of gun used. . . This circular continues to quote reports of tests made at Frankford Arsenal in 1896, said reports being still available to the curious handloader in the reports of the Chief of Ordnance for that year.

And yet the annual report of the Chief of Ordnance for the year ended June 30, 1897, solves the problem well. An extract from page 26 runs as

follows: "The principal cause of brittleness in the present shell, which is made of brass composed of 70 copper and 30 zinc, has been traced to the action of mercury in the primer in conjunction, possibly, with the use of an alloy of copper for the metal case containing a reduced percentage of zinc."

Guide Handloading

of the mercury in the primer composition reacting on the metal of the case, particularly on the zinc. . . . At a distant stage of the investigation it is expected that a serviceable reloadable cartridge will be produced by reducing the amount of fulminate

Micraphntofi by E. M. Chainot

Berdan type of primer showing foil disc. Figure 2, same primer with disc removed. Figures 3, 4 and 5, primer pellet mixtures as seen through the microscope. Note difference in those of various makes. Figure 5 is a mercuric primer. Notice tiny globules of free mercury in the mixture as evidenced by the round dots

In running down this extremely important problem, J. M. Barlow of Ideal wrote various manufacturers. Under date of March 22, 1898, Du Pont wrote that all primers contained fulminate of mercury, and that the larger amount necessary to ignite smokeless powders created the brittle cartridge-case problem, but that since smokeless fli and tte ignited fairly well with black-powder primers, they had much less trouble than when using the new .30-caliber high-pressure loads.

The King Powder Company, on March 18, 1898, practically supported the Du Pont statement with a similar letter, pointing out that their bulk powders had given very little trouble with the split-case problem.

The Marl in Firearms Company also came through with remarks on a particular test which ended after seventeen reloads.

UMC cases were used with #6^4 UMC smokeless primers; six shells being tested with Du Pont .30-caliber military and the other six with King's £1, Smokeless. After seventeen reloads, only two of the shells loaded with dense powder survived, while five remained from the King series.

The Laflin & Rand Powder Company reported that while damage to shells had been found in the small bores such as 6 mm. Lee, 7 mm., .30/40 Krag, .25/35, .25/36, and .30/30, they had found no damage with big-bore .45/70 cases; they reported a group of .45/70/500 shells loaded with smokeless powder, which they had reloaded more than fifty times without a single failure. The shells were not cleaned during the test. They also mentioned that Dr. A. A. Stillman of Syracuse, N. Y., had used one .32 Ideal necked down to a .28 caliber more than 175 times before it finally split lengthwise. Smokeless powder was used for all loads.

The general run of opinion, however, clearly indicates that smokeless powder and smokeless-powder primers were extremely tough 011 shells. Today we know the answer, as it was suspected by the Ordnance Department in 1897: The mixture developed by Alexander John Forsyth was poisonous to brass, particularly when smokeless powders were used.

Why with smokeless powders? The old-time writers neglected to point out a very significant fact. Black powder left a very serious residue, not only in the bore of the gun but also in the brass case. Riflemen soon learned that it was necessary to clean their brass eases to prevent corrosion. This black-powder fouling absorbs a large quantity of the free mercury released by the act of firing, thus negating the effect on brass. Smokeless powders left no such residue and therefore did not coat the brass with a heavy protective covering. They also burned at a higher pressure. Certain ballistic engineers to the contrary notwithstanding, the effect of a mercuric primer on a brass cartridge case is in direct proportion to the pressure within the case at the time of firing.

Early Primers. The problem of early-day primer manufacture did not necessarily mean the manufacture of a certain composition to ignite powder. It had to consider the working pressure and the guns to handle them. Early primers were made of copper, since they were designed for black-powder cartridges operating at a pressure of ten thousand pounds or lower. A soft copper cup was very necessary, since many of the early guns had weak hammers or firing-pin blows. Early repeating weapons were great oiTcnders in this. If the primer cup was too hard, it would fail to dent sufficiently to permit discharge under impact of the firing pin.

The two sizes of primers designed in the early days for rifle and handgun cartridges were very similar to the two sizes in use today. Their diameters run about .175 and .210 to accommodate various cartridges. A slight change was made in al! these primers, but it ran to length, with corresponding primer-pocket depth, more than to diameter. This is true even today. Generally speaking, the early handgun and rifle primers differed chiefly in material of the primer cup and its corresponding hardness, much as they do today.

The UMC #6 primer was one of the first to be made for the so-called ''sporting and military" sizes appearing in the early 1890'$. It did not work so well in the Krag cartridge, but was all right for such cartridges as the .30/30 and the UMC J8, which was also made of copper. This UMC jf8 proved to be sufficiently strong for high-pressure loads, although the UMC #Sl/2, practically the same primer in a brass cup, proved to be more popular for the .30/40, 6-mm. Lee, and similar sizes.

The first really successful smokeless-powder primer was the famous government primer "H-48," designed at the Frankford Arsenal for use in the .30/40 Krag cartridge. This primer appeared around 1898 and was the standard government primer for many years. It was similar to the UMC J8y2 except that it had a non-mercuric priming mixture and was widely copied by commercial ammunition makers almost from its introduction. A few boxes of sealed Winchester and UMC shells loaded commercially in 1901 were primed with a non-mercuric mixture, quite possibly the H-48. Two groups of these 1901 Winchester loadings are in the author's collection—one of them powered with Peyton (picric acid) powder manufactured by the California Powder Works, and the other with Du Pont .30-caliber Atl-

nular Smokeless. The latter used a brass cup, while the former has a brass cup containing a thin copper inner cup to hold the mixture. These ap-

in Bcrdan primers manufactured by the Western Cartridge Company for use in the French Lebel cartridge, but here the idea was to stiffen the cup

Components of primers as seen nnder the microscope. Figures 1 and 2, potassium chloride. Note variation in grain size. Figure 3, Tetryl (Trinitrothenyhnethylnitramine). Figure 4, T.N.T. Figure 5, fulminate of mercury. Figure 6, lead thiocyanate. All photos same magnification parently were swaged together before the insertion of the priming mixture, and the job was so well done that we discovered it only when dissecting primers for a chemical test in the laboratory. The double cup idea was used during the World War and prevent accidental discharge through contact of the pointed full-jacketed bullet in the tubular magazine of that rifle. It will be seen, therefore, that the double cup idea was not new—it had been tried at least fifteen years earlier.

Non-mercuric primers bccame items of importance to all ammunition makers at the turn of the century. A box of UMC 7-mm. cartridges loaded in 1900 used a primer which laboratory tests very clearly show to be non-mercuric. The idea apparently spread early and Frankford Arsenal developed its now famous #70 mixture in a non-mercuric and improved on the H-48 mixture. This primer, introduced in September 1919, is the accepted formula used at Frankford Arsenal today, since the Armory has not found a non-corrosive mixture with the necessary characteristics of reliability, life in storage and similar features required of military ammunition components.

The handloader today should watch his primers extremely carefully regardless of the type of gun they have been shot in. If they flatten too badly, regardless of the pressures of the load in question, he should either tone down the load or discard it entirely, as the primer, if it becomes pierced, will pour gas back through the mechanism in the direction of the shooter's eye. This is particularly true of old types of gun actions such as Ballard, Stevens and Winchester single shots, in which the primers arc only two or three inchcs from the shooters eye during the process of shooting. He should watch for too large firing-pin holes in the breech face or sharp-pointed firing pins which might puncture his primers. This is true even of bolt-action guns, in which the primer is three or four inchcs farther from the eye.

A good caution worth mentioning here is the recommendation that the handloader wear a pair of shooting glasses. A pierced or punctured primer may spit gas into the face and slightly scorch the cheek if glasses are worn, but it cannot damage the eyesight. Years ago, we had a punctured primer in a Winchester 54 and the resulting spit of hot gas into the face showed the author the importance of using shooting glasses at all times. It is better to be safe than sorry.

Primer Manufacture. How arc primers manufactured? The Peters Cartridge Company have listed a full seventeen distinctive steps in their manufacturing methods. Primers, like cartridge cases, begin life as sheet metal, either brass or copper, according to specifications. They arc first cut; then given a washing and cleaning; third, drawn to shape; fourth, assembled into steel plates, the drawings dropping into small pockets, cup side upright to receive the priming mixture. The fifth operation includes the charging of an entire perforated steel plate with wet priming mixture. This highly explosive dough is dropped 011 die steel plate very gently, and the operator, by means of a rubber squeegee, wipes it over the plate, completely filling the tiny pockets, each of which constitutes an individual primer charge. This plate is dropped into position over another plate containing the empty cups, and by means of a special punch arrangement the pellets are pressed through the plate into the waiting copper cups. The plates are then fed into a machine and the wet mixture packed into position, whereupon they are set aside for inspection.

After feminine operators weed out cups which appear to have an irregular amount of priming mixture, the approved cups go back into a machine which punches out a small disc of shellacked or waterproofed paper, inserts it over the primer mixture, and cements it in position with a tiny drop of shellac or varnish. The primers then appear like the Berdan style (without anvils), and are again inspected.

Anvils also begin life as sheet metal, the initial process being known as blanking and consisting of punching out sheet metal to the proper size and shape of anvil, so that a single operation completes the job. Anvils are then washed and dried to free them of oil, grease and debris. The primers, still charged into pockets of the plates, are now ready for the anvils. These are similarly charged into plates which are placed over the plates holding the primer cups. Anvils fit into a special plate in such a way that upside-down anvils in a properly operated factory are really a thing of the past, although mistakes occasionally occur. The two plates are placed together with the anvils on top and inserted into a special multiple punch press, the operation of a lever forcing the anvil from the assembling plate into the primer cups, whereupon the primers are completed and ready for the final inspection. Up to this time the priming mixture must be kept moist, otherwise serious explosions might occur. After being dried in special ovens the primers arc ready for ballistic tests.

All through the manufacture of primers, there is a rigid series of inspections, and the priming department is one from which visitors are usually barred. It is the one dangerous department in modern ammunition manufacture. Even today accidents occur occasionally. It has even been a practice of certain companies to pay an increasing weekly bonus to employees of the priming department if there has been no injurious accident or explosion within that department. The bonus increase ceases after reaching a certain point and remains at that figure until an accident occurs, whereupon all employees of that department go back to their former salaries. This system has helped to reduce accidcnts.

The above description of primer manufacture is only approximate. While this system is used in some factories and for some sizes and types, certain operations are varied in other factories. Modern machinery is rapidly reducing the so-called "plate methods" of charging primers and seating anvils and some of these operations are now strictly automatic with modern machinery. The system of inspection between stages, however, always has remained in force and probably always will, since the primer is the heart of the cartridge and a defective primer at a wrong time will totally cripple a gun and may cost the life of a hunter, soldier or law-cnforccmcnt officcr, should a misfire occur at a critical moment.

A GREAT many handloaders will recall the announcement less than ten years ago by Remington of the so-called "Klcanborc" primer— the "first" non-corrosive primer on the market. It is true dial Remington introduced the non-corrosive primer into this country, that is, as far as the average shooter's conception of their popularity is concerned. On the other hand non-corrosive primers are by no means new and date back to a period before the World War.

Since the author had the privilege of gaining advance information on a visit to the Remington laboratories where the Kleanbore primer was developed, he bccame extremely interested in this subject. For many years he made a study of the formulas and practices throughout the world. It may be a wild guess, but it is quite possible that mure than 100 formulas of non-corrosive primers have been patented throughout the world. Nearly one-half that number have been patented in the United States in the past twenty-five years.

In the assembling of data on primers, the author is greatly indebted to Professor Emile M. Chamot, of the Department of Chemistry of Cornell University. Professor Chamot is probably one of our greatest primer authorities of today. During the World War he was very active on behalf of the United States Government in developing numerous forms of tests of primers, and in this work has probably handled half a million of the little pellets merely in laboratory examination with the aid of his able corps of assistants.

To understand the action of the non-corrosive primer, one must first understand the performance of the old-style corrosive mixture. As previously stated, the old formulas are essentially of the non-mercuric type, a combination of potassium chlorate and antimony sulphide. When these two elements are mixed together they have a tendency to combine chemically under the influence of heat such as that produced by a blow or friction. The result of this chcmical action is three separate chemical combinations—potassium chloride, antimony oxide and sulphur dioxide, the latter, of course, a gas. This is a highly explosive mixture—a gas generated at high temperature in an extremely short time. The temperature resulting from this reaction is about 3500° centigrade—nearly 6400° Fahrenheit.

Technically, this reaction, leaving out all the chemical symbols, is: Potassium chlorate plus antimony sulphide equals potassium chloride plus antimony oxide, plus sulphur dioxide. Similarly fulminate of mcrcury and potassium chlorate change into free mercury, nitrogen, potassium chloridc and carbon dioxide. These combinations of chcmicals with potassium chlorate omitted are by no means as sensitive as is desired for primer use. Accordingly it is necessary to add some form of abrasive such as powdered glass to produce the necessary friction to cause it to respond to a hammer blow. The so-callcd non-fulminate primers have the mercury fulminate replaced entirely by sulphur, lead or coppcr sulphocyanide with small additions of such substances as T.N.T. and tetryl.

In the non-corrosive types of primers the potassium chloride is replaced wholly or almost wholly by the barium peroxide, barium nitrate and lead peroxide. It has been definitely proved many times that potassium chlorate, which produces potassium chloride, is responsible for the rusting or corrosion of gun barrels. Thus the necessity for eliminating it from the formula.

The first practical non-rusting rimfire priming was the German .22 "R" cartridge which was very popular from 1910 to 1913. This cartridge was widely sold, not only on the Continent but in England. It was a smokeless cartridge and the powder did not give an alkaline residue, so the non-corrosive primer was a distinct advantage. The composition of the famous "R" priming was as follows: Mcrcury fulminate 55%, stibnitc 11%, barium peroxide 27%, T.N.T. 7%.

Since this formula is very similar to those in use today, it is well to analyze it to determine exactly what happens. Barium peroxide gives up oxygen and becomes barium oxide. The latter combines with the carbon dioxide, also a product of combustion, and becomes barium carbonate. The latter is a hard, flinty substance. The fine particles form on the combustion and act as a very effective abrasive when the bullet travels down the bore. Thus, this particular type of priming mixture crcatcs severe erosion, which is frequently far more serious than rusting or corrosion. Thus in the .22-caliber line, the Lesmoke cartridge when introduced soon superseded the German "R" cartridge. Bccausc of the Lesmoke powder, which gave an alkaline residue, the ordinary primer could he used, thus elimi-

1822 6mm Pistol

Microphoto by E. M. Chamot

Hornet cartridge case which had been primed with a mercuric primer of the non-corrosive type (new case) and fired once. Head pulled off in resizing die. Note crystalline structure of the break around the edge. This is an excellent example of what mercury docs to brass nating both erosion and corrosion with reasonable cleaning of the bore.

Although the Remington Company announced the non-corrosive or "Kleanbore" primer in the .22-long rifle as their first development, this actually

Microphoto
Microphoto by E. M. Chamot

Winchester #225 non-mercuric, non-corrosive primer was developed for experimental work in the .25/20 repeater cartridge. Analysis of this so-called great development shows that it is by no means original. It is very similar to the so-called non-corrosive or non-rusting shotgun primer composition used 011 the Continent many long years before Kleanbore primers were invented. The only major change was the increase of ground glass.

Microphoto by E. M. Chamot

Winchester #111 non-mercuric, non-corrosive revolver primer

In primers there arc two poisonous ingredients that are by no means satisfactory and the loss of which would be no great hardship for the shooter. These ingredients are barium nitrate and glass. The barium nitrate has, as a product of its combustion, barium carbonate, a severe abrasive, and of course powdered glass is wicked on anything.

Guide Handloading

Microphoto by E. M. Chamot Remington UMC #39 rifle primer (now known as

Priming mixtures have been greatly improved however, within the last ten years. As a mattet of fact, more than thirty patents have been taken out on American priming formulas. Most of these patents really indicate that the person responsible for the development is by no means a practical shooter, as he docs not understand the problems of barrel length. Many of these patented formulas been thoroughly stabilized and are reliable under all service conditions, they will not recommend them or seriously consider their adoption.

On the other hand, the non-corrosive primer is here to slay. Improvements arc continually taking

Guide Handloading

Microphoto by B. M. Cha mot

Remington #Wi non-corrosive revolver primer have never been used commercially because they are highly impractical. The author has had analyses made by reputable laboratories to determine the primer ingredients in modern non-corrosive primers of all makes. He has found a great varia-

A primer of a German .22 rimiirc cartridge as viewed under the microscope. This is of the non-mercuric non-corrosive type. Notice how much more uniform the pellet is than that used in the American primers place, and one will not go far astray if he uses the commercial brand exclusively for his handloading. The formulas arc being approved so rapidly that

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    How to make 3855 brass from 3030 brass?
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    What are the composition of priming mixture developed by alexander john forsyth?
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