magnum primers ?
- Thread starter rebs
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In so far as primer characteristics primer manufacturers can vary primer cake sensitivity, cup thickness, and anvil characteristics.
Picatinny Arsenal document, PATR 2700, says this about primer sensitivity:
So, here Picatinny is telling us the primer manufacturer can change cup thickness, anvil tip shape, and anvil/primer cup distance, given a fixed primer cake composition. Generally speaking, primer cake composition is kept constant by the manufacturer. It was hard enough for these guys to come up with a good primer mix and they don't like to monkey around with something that works.
FA 956 is a small arms primer composition that came out of a joint industry and military cooperation program in the 1950's.
PATR 2700 Encyclopedia of Explosives gives the composition
FA 956
Lead Styphanate 37.7 +/- 5%
Tetracene 4.0 +/- 1%
Barium Nitrate 32.0 +/- 5%
Antimony Sulfide 15.0 +/- 2%
Aluminum Powder 7.0 +/- 1%
PETN 5.0 +/- 1%
Gum Arabic 0.2%
There are plenty of primer compositions for there are many applications for primers other than small arms. This is a list of military priming mixtures, FA 70 is the old corrosive 30 cal primer, FA 90 was the corrosive 50 cal primer. I was able to identify PA101 as a fuse primer composition. All of the compositions to the right of FA90 are more sensitive than rifle primer compositions, so these are probably used on a variety of explosive or propellant devices.
Commercial manufacturers are free to vary what ever they like, but they try to stay within SAAMI boundaries for sensitivity. When they are making military ammunition, they have to meet contract requirements. It is likely military primer characteristics are still as what Unclenick has posted. If the military ammunition maker creates ammunition where the primers are so sensitive that it causes doubling, slamfires, or out of battery slamfires, the Military has the resources to pursue legal penalties. I have never heard of a civil suit by a civilian brought against an ammunition maker for damages caused by overly sensitive primers. Individuals don't have the money to sue a multi-billion dollar Corporate entity, such as ATK, and win.
In the book, "Ammunition Making", by Frost, the author provides cup thicknesses for pistol and rifle ammunition, and Frost provides dimensions that show the military cup is thicker. So whatever manufacturer he was working for, they were making the cup thicker, and maybe there were some other manufacturer's doing the same thing.
Information on primer characteristics has been very hard to acquire. American corporations don't make money educating us, in fact, they like to keep us stupid, as our ignorance becomes their strength. Ignorant people are easily swayed by superstition, emotional appeals, and misinformation. Educated people are harder to manipulate. So what you find is very little information in the public domain, and what is there, is either advertising, which is unreliable, or very old military technical data, which may not be current or relevant. The absolute best book I have found on primers is George Frost's book Ammunition Making. The author even tells you how to make you own primer cake, and he provides all sorts of primer sensitivity data. I am glad I bought that book when it first came out, as it is out of print and prices on Amazon are ridiculous. Knowledge is not cheap, but ignorance is free.
Picatinny Arsenal document, PATR 2700, says this about primer sensitivity:
So, here Picatinny is telling us the primer manufacturer can change cup thickness, anvil tip shape, and anvil/primer cup distance, given a fixed primer cake composition. Generally speaking, primer cake composition is kept constant by the manufacturer. It was hard enough for these guys to come up with a good primer mix and they don't like to monkey around with something that works.
FA 956 is a small arms primer composition that came out of a joint industry and military cooperation program in the 1950's.
PATR 2700 Encyclopedia of Explosives gives the composition
FA 956
Lead Styphanate 37.7 +/- 5%
Tetracene 4.0 +/- 1%
Barium Nitrate 32.0 +/- 5%
Antimony Sulfide 15.0 +/- 2%
Aluminum Powder 7.0 +/- 1%
PETN 5.0 +/- 1%
Gum Arabic 0.2%
There are plenty of primer compositions for there are many applications for primers other than small arms. This is a list of military priming mixtures, FA 70 is the old corrosive 30 cal primer, FA 90 was the corrosive 50 cal primer. I was able to identify PA101 as a fuse primer composition. All of the compositions to the right of FA90 are more sensitive than rifle primer compositions, so these are probably used on a variety of explosive or propellant devices.
Commercial manufacturers are free to vary what ever they like, but they try to stay within SAAMI boundaries for sensitivity. When they are making military ammunition, they have to meet contract requirements. It is likely military primer characteristics are still as what Unclenick has posted. If the military ammunition maker creates ammunition where the primers are so sensitive that it causes doubling, slamfires, or out of battery slamfires, the Military has the resources to pursue legal penalties. I have never heard of a civil suit by a civilian brought against an ammunition maker for damages caused by overly sensitive primers. Individuals don't have the money to sue a multi-billion dollar Corporate entity, such as ATK, and win.
In the book, "Ammunition Making", by Frost, the author provides cup thicknesses for pistol and rifle ammunition, and Frost provides dimensions that show the military cup is thicker. So whatever manufacturer he was working for, they were making the cup thicker, and maybe there were some other manufacturer's doing the same thing.
Information on primer characteristics has been very hard to acquire. American corporations don't make money educating us, in fact, they like to keep us stupid, as our ignorance becomes their strength. Ignorant people are easily swayed by superstition, emotional appeals, and misinformation. Educated people are harder to manipulate. So what you find is very little information in the public domain, and what is there, is either advertising, which is unreliable, or very old military technical data, which may not be current or relevant. The absolute best book I have found on primers is George Frost's book Ammunition Making. The author even tells you how to make you own primer cake, and he provides all sorts of primer sensitivity data. I am glad I bought that book when it first came out, as it is out of print and prices on Amazon are ridiculous. Knowledge is not cheap, but ignorance is free.