Hardest Large rifle primers
- Thread starter BoogieMan
- Start date
I don't know what number you are referring to? I don't know of any primer maker who publishes their sensitivity specs, except that the CCI sensitivity specs for their #34 (LR) and #41 (SR) primers will match the published military spec. The "hardness" of the primer cups used in those two primers are identical to CCI 250 and CCI 450 magnum primers, as is the priming mix itself, but they use a wider leg angle on the anvil inside, making it shorter, and that lessens the sensitivity of the primer.
You can also buy the Russian made Tulammo KVB762 large rifle primers that are made to NATO ignition sensitivity specs. Unlike the #34, it is not a magnum primer, but with stick powders it seems to produce smaller velocity SD's even if it may not ignite H380 and 748 quite as consistently. They are unfortunately harder to seat than domestic primers.
The way primer sensitivity is determined is with what is called an H-test. A cartridge case is primed and placed upside down in a holder with a floating firing pin resting on it. A standard weight is dropped from different measured heights (the 'H' in H-test is for 'height') straight onto the firing pin, so its kinetic energy is transferred through the pin the primer. The number of inches the weight fell is then a measure of that ignition energy. The H number for the primer is its nominal sensitivity. The portion of the primers that go off at drops below the H value is limited by a specified standard deviation multiple. The portion that can fail to fire when hit with energy above the H value are likewise limited to a minimum number by an allowed standard deviation multiple.
An example military specification is below.
You can also buy the Russian made Tulammo KVB762 large rifle primers that are made to NATO ignition sensitivity specs. Unlike the #34, it is not a magnum primer, but with stick powders it seems to produce smaller velocity SD's even if it may not ignite H380 and 748 quite as consistently. They are unfortunately harder to seat than domestic primers.
The way primer sensitivity is determined is with what is called an H-test. A cartridge case is primed and placed upside down in a holder with a floating firing pin resting on it. A standard weight is dropped from different measured heights (the 'H' in H-test is for 'height') straight onto the firing pin, so its kinetic energy is transferred through the pin the primer. The number of inches the weight fell is then a measure of that ignition energy. The H number for the primer is its nominal sensitivity. The portion of the primers that go off at drops below the H value is limited by a specified standard deviation multiple. The portion that can fail to fire when hit with energy above the H value are likewise limited to a minimum number by an allowed standard deviation multiple.
An example military specification is below.
I'm fairly new to reloading for my Garand, about 2 thousand rounds, and believe you're overthinking primer "hardness" requirements. While slam fires are a distinct possibility, I nor anyone I know have ever had one. I use CCI, Winchester, Remington, and Wolf primers and just make sure they are properly seated, below flush...
Marco Califo
New member
CCI #34. That is why they exist.
Second choice is any available LR Mag.
Second choice is any available LR Mag.
I know many people have never had an issue. Many people also have not been eaten by a shark. Doesn't mean I I will do anything I don't have to to increase my chances of a slam fire or being shark dinner. I swim in the ocean so I'm willing to assume a certain amount of risk.
Anyway,
Unclenick- the numbers I was referring to are the primer manufacturer model numbers. Like CCI# 34.
I will search out some #34 primers local because I hate paying the crazy s&h costs. Wondering if there are any others that are the equal. Federal, remington, winchester, xxxx.
Tula is never on anyone's shelf. Last time I got tula was a special from Natchez on small pistol at around $5.50 per thousand. I still have several thousand.
Anyway,
Unclenick- the numbers I was referring to are the primer manufacturer model numbers. Like CCI# 34.
I will search out some #34 primers local because I hate paying the crazy s&h costs. Wondering if there are any others that are the equal. Federal, remington, winchester, xxxx.
Tula is never on anyone's shelf. Last time I got tula was a special from Natchez on small pistol at around $5.50 per thousand. I still have several thousand.
Natchez is the last place I got a couple of slips of the Tula primers, too. I got both the 556 NATO spec, which are magnum, and the 762 NATO spec which are not. AFAIK, the CCI#34 and Tula KVB762 are the only commercially available large rifle primers that are made to the mil sensitivity spec.
In small rifle primer size there are three available mil spec primers, the CCI #41, the Tulammo KVB556M and the Federal GMM205MAR, which is a 205M primer, but Federal told me they use a thicker cup to achieve the lower sensitivity, rather than mod the anvil the way CCI does. I don't know what Tula does differently as I don't have any of their standard sensitivity spec primers to compare them to.
I obviously agree with your decision to minimize risk. I've been present for at least half a dozen slamfires at matches over the years, and those are just the ones I heard because they occurred when the command to load was given. Ones that occurred in the middle of a string would have been masked by other firing. So I think the guys who have never seen one just aren't getting out into that larger volume shooting environment.
In small rifle primer size there are three available mil spec primers, the CCI #41, the Tulammo KVB556M and the Federal GMM205MAR, which is a 205M primer, but Federal told me they use a thicker cup to achieve the lower sensitivity, rather than mod the anvil the way CCI does. I don't know what Tula does differently as I don't have any of their standard sensitivity spec primers to compare them to.
I obviously agree with your decision to minimize risk. I've been present for at least half a dozen slamfires at matches over the years, and those are just the ones I heard because they occurred when the command to load was given. Ones that occurred in the middle of a string would have been masked by other firing. So I think the guys who have never seen one just aren't getting out into that larger volume shooting environment.
Having and seeing a slamfire sure changes one's attitude towards the whole thing. I attended a regional recently and talked to a 78 year old Marine (once a Marine always a Marine!) and he shot Garands at Camp Perry during late 1950's through the transition to the M14. He never had or saw a slamfire. But understand, shooters were issued ball ammunition or NM ammunition. The Army made its own ammunition, it understood both the characteristics of the weapon and the ammunition.
There was also a certain liability associated with accidents. I don't know when the no liability period ended, but I am aware in the 1920's, costs for rehabilitation of Service members was paid for by an Agency outside the Services. So, blowing up Army, Navy, Marine service men, with single heat treat Springfields, for example, cost the services the use of a rifle and the price of patching up the injured and sending them off to the other Government Agency. So, giving Service members dangerous equipment did not expose Military Agencies to any long term costs or obligations. That must have ended, and the services became aware that injuries and long term care was expensive. So during the Garand period, the Army had a real monetary reason to produce the safest ammunition possible. I am sure the Army scrapped lots of primers that were too sensitive. Someone got yelled at for certain, but sensitive primers would have been rare.
Then came commercial primers and civilians. Ammunition companies have zero liability if a civilian blows himself or his rifle up with their primers. The number of slamfire incidents with commercial primers exceeds by an order of magnitude reports of slamfires with military ammunition.
As for primers not to use, I don't recommend Federals. They are too sensitive, though many shooters loved them because they could buy a box of primers with the name "Match" beside the name Federal. Names sell primers and people think match primers are better, even though we don't know how much better they are over those nasty "standard" primers. Since standard primers shoot very well, I doubt there is much of a significant difference between "Match" and "standard".
For Garands, M1a's, I recommend using the mil spec primers as that is the primer type the military used.
Marco Califo
New member
CCI #34 are the one and only U.S. 7.62mm milspec primer.
CCI#41 are the one and only U.S. 5.56mm milspec primer.
Not so coincidentally, CCI is a subsidiary of ATK, which is the current contracted operator of the U.S. Lake City Army Ammunition Plant since 2001.
I grew up in So. CA, swam in the ocean, scuba dove, snorkled, boated, sailed to Catalina many, many times, surfed, and fished for sharks and in 62 years never got bit. I have fired nearly 1800 reloads in my Garand using various primers, but no 34s, with no slam fires. Am I just Blessed? 
CCI #34 and #41 primers are nothing more than magnum primers. Totally unnecessary for reloading for any battle rifle. Brilliant marketing plan though.
The term "mil spec" is a marketing term only. Everything the military uses from paper clips to socks is milspec.
Regular large rifle primers, seated properly, will be fine.
Primer manufacturer model numbers mean nothing except to their inventory and marketing people.
The term "mil spec" is a marketing term only. Everything the military uses from paper clips to socks is milspec.
Regular large rifle primers, seated properly, will be fine.
Primer manufacturer model numbers mean nothing except to their inventory and marketing people.
I have been a DOD contractor for years so I am familiar with mil spec. It means that it adheres to the specification set forth by the DOD. In somr cases the comercial equivelant also would, however the paper work hasnt been completed to prove it. The question in this case is if that differs from the comercial specification. All the evidence that others have provided leads me to believe that they are in fact different parts. I have a link that someone sent me that shows the difference clearly. Unfortunately I can't link it from my phone. I will post it later or tomorrow.
condor bravo
New member
Well I usually get the CCI 200s, standard LR, for the Garand but yesterday the LGS was out of 200s so gave in to marketing and got the 34s. Usually they don't have the 34s. At one time could only get the 41 SR primer but these were definitely too hard or overly insensitive for use with an older Winchester lever action in .25-20.
This is a great article that was sent to me from SKS boards. Very informative on primers.
http://www.sksboards.com/smf/index.php?topic=56422.0
This is the chart for Tula primers- http://www.mpzflame.ru/production/primers/
http://www.sksboards.com/smf/index.php?topic=56422.0
This is the chart for Tula primers- http://www.mpzflame.ru/production/primers/
T. O'Heir said:
That is a gratuitous assertion of personal opinion as if it were a fact. It contradicts part of the design difference information provided to me directly by CCI. Readers acting on that statement as if it were true assume some degree of risk. It is small, especially if you don't shoot much, but very real, as board member Slamfire has documented extensively in other threads.
Marco Califo said:
Have to be a little careful about the terminology here. The CCI versions of the #34 and #41 are commercial grade primers with their sensitivity reduced by redesign of the anvil. Otherwise, they are identical in cup dimensions and priming mix formula and quantity to the CCI #250 and CCI #450 primers. I have this directly from horse's mouth.
To qualify for mil-spec, a primer has to undergo far more rigorous lot validation testing than a commercial primer does. I have a copy of the protocol somewhere, and it involves firing thousands of primers for things like reliability at temperatures down to -65°. Civilian primers don't normally requires that degree of ignition reliability proof. CCI does make mil spec primers under contract. The easiest way to spot them is the don't have the nickel plating their commercial grade primers do.
Swimming in the ocean once and getting bit by a shark is prolly a million to one occurrence, but life threatening. A slam fire even if its only 1,000 to one chance isn't normally life threatening (scary, yep, and rough on the underwear). There's a chance of getting in an accident within 5 miles of home, do you wear your helmet in your car? There's a chance of getting struck by lightening, have you ever gone out in the rain? I heard of "blue ice" falling from the sky from air planes, should I stay indoors?
Precautions are great, but paranoia is debilitating...
I just ordered a new aluminum foil hat, I read somebody was had their brain downloaded into a monster computer by aliens. Yep it's true, I read it in the Enquirer...
Precautions are great, but paranoia is debilitating...
I just ordered a new aluminum foil hat, I read somebody was had their brain downloaded into a monster computer by aliens. Yep it's true, I read it in the Enquirer...