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THE PRIMER IS THE HOT HEART OF ANY LOAD,
IN A FLASH of white-hot fire, a primer expends its working life. The time is measured in micro-seconds. Dormant until a trigger is touched, primers set off an explosion-combustion sequence that starts a bullet on its way to a target. produced by the billions, each composed of a trifling amount of copper and chemicals, they are so cheap we seldom give them a second thought. But in some countries. primers are more precious than gold -- as, for instance, in Bangkok, Thailand, where wages average $1 a day. According to rifleman Amphel Iddhikasam: "One must pay 'tea money' (a bribe) amounting to about $100 to the police for a license to purchase a gun. It's payable in advance, with no guarantee the license will be issued. Guns themselves are very expensive. And, finally, a license to purchase ammo must be obtained from the police every 90 days. It allows the purchase of only 15 rifle, 25 shotgun, or 12 pistol rounds. Shotshells cost 60c to 80c each, and large rifle cartridges cost $1.00 to $1.20 each. This situation causes me to handload all of my ammunition. "I recharge fired primers for my friends and myself, using an old corrosive formula. I am very lucky, as the mixture has only exploded twice. One accident put me flat in bed for some weeks. I couldn't move and my fingers became a white color from the heat of the explosion. I am also very lucky to own some Ideal dies from the U.S. I turn bullets on a lathe, using a copper tube filled with lead. Powder is salvaged from old artillery shells and ground up." Fortunately, Americans don't have to spend six months wages to buy a gun, plus half that figure to bribe the police for a permit, although some people would like to have it that way. Nor do we have to attempt the extremely dangerous job of making priming compound. Just what happens when you bag a buck making a fast getaway? A clean kill means that you, your gun, and the cartridge were working as an efficient team. When the firing pin hit the primer, it pinched some impact-sensitive compound against a tiny anvil. The explosion spewed fire through a flash hole .08" in diameter, to ignite some of the powder, which started making a large amount of hot gas under pressure. As more powder burned in the confined chamber, it created more heat and gas until a of perhaps 55,000 pounds per square inch developed. You were holding a hand grenade, except for the fact that the pressure drove the bullet out the bore, thus offering a safe outlet for the gas. All this happened in thousandths of a second. Yet the components were selected by the factory, or by you as a handloader, to insure predetermined results. Clever, wasn't it? But not so clever if the primer gave punk ignition, or misfired, which sometimes happens. Except for oil or moisture, ignition was no problem with the old 1-2-7 mix of sulphur, charcoal, and saltpeter used in black powder. A spark from a cat's whisker would ignite it. Came smokeless powder, and ignition troubles reared their ugly heads. These troubles are still present to some extent. Primers must make a lot of heat in a hurry to ignite slow burning rifle powders quickly; and with the heat they produce gas. The less gas produced by the primer the more uniform will be the velocity and pressure. Modern primers are hotter than a firecracker. Snap an amply primed rifle case in the dark and note the loud report and flash a couple of feet beyond the muzzle. But the long flash is not necessarily an indication of perfect ignition, which may be slow, erratic, or productive of high pressure. You'll never notice such faults until you shoot for groups. Slow ignition won't be noticed except by the grouping until it may be 1/10 second or more. I had one factory cartridge hang fire for almost 30 seconds. Under-ignition is most often caused when only a part of the priming compound fires. When the powder is not fully ignited, accuracy is terrible. This sometimes is a great alibi, in a match. Over-ignition is most often caused by too-sensitive primers. It's difficult to make a uniform composition of all ingredients in each primer, with the exact amount of compound needed. The result is, different lots and makes of primers exposed to high temperatures may have pressure variations as great as 20,000 pounds per square inch. One make of primer in .30-30 cartridges was stored a month at 140°F. The pressure increased an average of 10,000 psi, which wasn't considered abnormal in that make. Velocity increased 200 feet per second. Throughout the world, most ammunition makers fabricate their own primers. Frequently they supply primers to smaller specialty loaders, either as empty primed cases or separate primers. The European-style Berdan primer is made without an anvil -- this is formed in the case head. American primers are "Boxer" type, containing the anvil and usually firing through a single central flash hole. Boxer primers are made abroad for export, and are the only style made in the U. S. Strangely, Colonel Boxer was a European (British), while Colonel Berdan was an American. American factories turn out ammunition by the millions, but shooters consume primers by the billions. So great has been the demand for good primers that new firms manufacturing and distributing, have sprung up since 1946!
A firm making more than a flash in the primer field is Cascade Cartridge, Inc., Lewiston, Idaho, headed by Richard A. Speer. After giving C.C.I. primers every test I know, which they passed with flying colors, I believe they are superior to any other make, for handloading. Our tests indicate extreme uniformity in the compound and cup dimensions, with anvils perfectly seated. A top bench-rest shooter told me primers were the major variable in such shooting, and I fully agree. Ralph Pride, the barrel maker in Portland, Oregon, used Dick Speer's primers to set a new world record at Johnstown, N.Y., in 1955. His five, 10-shot groups at 100 yards averaged only .343", with one group .244". Since then, C.C.I. primers have made many wins in rifle and handgun competition. The cup and anvil thickness, hardness and dimensions will effect ignition and accuracy. The formula has much to do with accuracy, ignition, stability and barrel life. The old G.I. FA70 mix gave good ignition but was very corrosive. It used 25% Lead Sulfa Sulphocyenate and 17% Antimony Sulfide as fuels. The 53% Potassium Chlorate provided oxygen and was the corrosive salt. 5% T.N.T. helped control the rate of burning. A cheap non-corrosive non-mercuric (N/C-N/M) compound is Red Phosphorus 25% and Barium Nitrate 75%. The disadvantage is it has a high affinity for moisture and a short shelf life. It's best when used within eight months. All modern American primers use Lead Styphnate as the sensitizing ingredient, with other chemicals to liberate oxygen or fuels to supply heat. Some European primers still use Mercury Fulminate and some use Lead Styphnate with Ground Glass as a sensitizing agent. Neither type is desirable for the American handloader. C.C.I. uses various compositions with Lead Styphnate which makes the best primers, because the ingredients can be non-hygrosaopic, have a very long shelf life, are non-corrosive and non-mercuric, and the flame, heat, and duration of flame can be controlled for the purpose intended. The disadvantages are, it is about ten times as costly as the FA70 mix and is much more hazardous to make. Let's take a look at a complex and costly mix C.C.I. developed especially for their excellent pistol primers. Comparatively speaking, it burns rather than explodes, and provides the right amount of heat over the right length of time to uniformly ignite every particle of powder in the case:
Ingredients from one to four are the source of heat and flame. Ingredients five through eight are stabilizers and control heat and flame similar to that of Tetraethyl Lead in motor fuel. Each type of C.C.I. primer has a mix best suited for the purpose, rather than varying the amount of compound in different primers. All ingredients are combustible, with no ground glass or other non-combustibles added. Our own drop tests show a high uniform sensitivity, which is necessary for a uniform velocity and pressure. C.C.I. President Dick Speer adds some interesting facts: "In addition to other qualities, primers must yield uniform velocity, provide adequate ignition for all suitable powders without creating high pressure, have uniform operation through a wide temperature range, and have a long, stable shelf life. If the perfect primer could be made, it would ignite the powder without creating any pressure. Then bullet velocity would depend only on the powder to produce the least possible available variation. To achieve this condition as nearly as possible, C.C.I. has developed mixtures that could be called progressive burning as compared to an explosion. We reduce gas volume to a minimum by inducing heat to the powder in the form of flaming particles. In other words, part of the primer compound actually burns within the charge, and is not all flame and gas sguirted through the flash hole. The pressure build up is uniform with C.C.I. primers. "We have exposed our primers to artificial weather conditions of extreme humidity, cold and heat. Lab tests indicate they have a shelf life under average conditions of more than 35 years. A 30-06 hunting grade rifle has been fired more than 60,000 rounds with heavy loads and still has hunting accuracy. The test loads were 150 grain bullets ahead of 50 grains 4198. From thousands of test mixtures we have selected the ones best suited for handloading with the type of tools available. All of our primers are N/C-N/M, with no non-combustible abrasives. "C.C.I. primers are very carefully made with high quality control. Samples are checked hourly to determine pellet weight uniformity. Every primer must pass a 200% optical inspection under a luminous magnifier. One inspection checks for defects and the other is a double inspection." The Cascade plant is composed of seven buildings on six acres, with a fully equipped Tool & Die Shop, a Metal Parts Fabrication, Chemical & Physical Research, and other departments. Dr. Victor Jasaitis, famed munition chemistry specialist for 26 years, is director of the Chemical Division. When C.C.I. was awarded a $288.000 government contract. Speer was proud it required primers to be made to Cascade specifications, rather than government specifications. Uncle can do a whale of a lot of shooting with that many primers. The firm has filled other G.I. orders and has prospects for more. They require tremendous production, but Dick's first love is still the individual handloader. When an ammo factory changes lot numbers of primers they adjust the charge to stay within certain limits of pressure and velocity. If you sight-in your rifle with one lot number, then hunt with another lot, or another brand, that may account for some misses. This lack of uniformity is why it's good business for those who use commercial ammo to test various makes to see which performs best in their rifle. Then it's good business to buy a supply of that particular lot number, generally stamped on the inside of the box flap. It also accounts for the fact that careful handloads are more accurate and uniform than factory fodder; otherwise the "stool" shooters could never consistently group 10 shots in less than ½" at 100 yards. I do not consider handloading any more dangerous than a score of other hobbies that are considered "safe." Making primer compound is extremely hazardous, and unless you live in a place like Thailand, it is absolutely unnecessary. You can not hope to equal the inexpensive factory primers, and even skilled workers have accidents. Dick Speer said, "A heavy wooden table 6 feet long was turned into toothpicks when 4 ounces of compound detonated. It simply disintegrated. The wall was cracked and windows shattered. A person not far from the table was injured, but did survive." To sum up, just a tiny bit of priming compound makes a TNTerrific explosion. | ||||||||||||||||||||||||
