harder primers
- Thread starter Mongo62
- Start date
TurboTapin
CGN Regular
- Location
- Saint-Joseph du lac, QC
Are you using CCI 400's ? They tend to me some of the thinness primers. You can either bump it up to CCI 450's, or any other thicker cupped primer.
Use this or any other primer cup thickness chart to give you an idea. http://www.accurateshooter.com/technical-articles/primers-and-pressure-analysis/
400's tend to work fine in AR's though... make sure your firing pin is still in good condition, and that your bolt isn't all gunked up.
Cheers.
Use this or any other primer cup thickness chart to give you an idea. http://www.accurateshooter.com/technical-articles/primers-and-pressure-analysis/
400's tend to work fine in AR's though... make sure your firing pin is still in good condition, and that your bolt isn't all gunked up.
Cheers.
CCI #41 primers are made for ARs, well 5.56 so yeah, for ARs.
I have been doing a lot of reading on this as well and many say that any primer will do, but I'm not willing to risk slamfires, so CCI #41 primers it is.
There are far more knowledgeable folks on here than me, so please don't take my word as gospel.
I have been doing a lot of reading on this as well and many say that any primer will do, but I'm not willing to risk slamfires, so CCI #41 primers it is.
There are far more knowledgeable folks on here than me, so please don't take my word as gospel.
Perfect timing. I'm pretty new to reloading and was just reading about thin/soft primers in semi's. I see on the above chart the thickness are all the same for large rifle. One of the books I was reading says there are 'military' primers that are harder? Thanks, Dan
CCI recommends M41 primers for semi-autos (M41 is for 5.56 and M34 is for 7.62):
CCI No.34 & No.41 military rifle primers
Military-style semi-auto rifles seldom have firing pin retraction springs. If care is not used in assembling ammunition, a “slam-fire” can occur before the bolt locks. The military arsenals accomplish this using different techniques and components—including different primer sensitivity specifications—from their commercial counterparts. CCI makes rifle primers for commercial sale that matches military sensitivity specs that reduce the chance of a slam-fire when other factors go out of control*. If you’re reloading for a military semi-auto, look to CCI Military primers.
*Effective slam-fire prevention requires more than special primers. Headspace, chamber condition, firing pin shape and protrusion, bolt velocity, cartridge case condition, and other factors can affect slam-fire potential.
Features:
•Initiator mix optimized for ball/spherical propellants
•Available in large (No.34) and small (No. 41) rifle
•Use the same data as CCI Magnum primers
X-reload has them in stock.
CCI No.34 & No.41 military rifle primers
Military-style semi-auto rifles seldom have firing pin retraction springs. If care is not used in assembling ammunition, a “slam-fire” can occur before the bolt locks. The military arsenals accomplish this using different techniques and components—including different primer sensitivity specifications—from their commercial counterparts. CCI makes rifle primers for commercial sale that matches military sensitivity specs that reduce the chance of a slam-fire when other factors go out of control*. If you’re reloading for a military semi-auto, look to CCI Military primers.
*Effective slam-fire prevention requires more than special primers. Headspace, chamber condition, firing pin shape and protrusion, bolt velocity, cartridge case condition, and other factors can affect slam-fire potential.
Features:
•Initiator mix optimized for ball/spherical propellants
•Available in large (No.34) and small (No. 41) rifle
•Use the same data as CCI Magnum primers
X-reload has them in stock.
Remington ran our American Lake City Army Ammunition Plant from 1941 until 1985, and then Winchester ran the plant from 1985 till 2001.
And when both Remington and Winchester ran Lake City the CCI 41 and 34 primers were never used, or even invented yet.
Meaning the thicker CCI primers were used after ATK took over the Lake City plant in 2001.
Bottom line the M16 rifle made it through the Viet Nam war using Remington's 7 1/2 primers. And the thicker CCI 41 and 34 primers are a solution for a problem that did not exist.
Both the M14 and M16 rifles had their firing pin lightened during the testing phase. And this was to prevent slam fires when loading a single round without the magazine in place. With the magazine in place it slows down the bolt velocity and firing pin inertia and no slam fires.
The biggest cause of slam fires are high primers not seated below flush with the base of the case.
It is recommended to use primers with a cup thickness of .025 with ammunition used in the M16 type rifles.
Read the link below, I had a SKS go full auto but this was caused by a binding firing pin. I'm loading for three AR15 rifles and use Remington 7 1/2 primes and never had a single problem.
CHOOSING THE RIGHT PRIMER - A PRIMER ON PRIMERS
http://www.sksboards.com/smf/?topic=56422.0
Below is a No.41 primer drawing, the cup is thicker in its base and the anvil is shorter. Meaning it takes more force to set off the primer, BUT this type primer was never used before 2001.
Bottom line, the CCI 41 and 34 primers were nothing more than a way to charge the U.S. Government more money for primers and ammunition made at Lake City. And were never used until after 2001 when ATK took over the contract to produce ammunition at Lake City.
And primer sensitivity is governed by cup thickness, the hardness of the brass cup and the height of the primers anvil.
And when both Remington and Winchester ran Lake City the CCI 41 and 34 primers were never used, or even invented yet.
Meaning the thicker CCI primers were used after ATK took over the Lake City plant in 2001.
Bottom line the M16 rifle made it through the Viet Nam war using Remington's 7 1/2 primers. And the thicker CCI 41 and 34 primers are a solution for a problem that did not exist.
Both the M14 and M16 rifles had their firing pin lightened during the testing phase. And this was to prevent slam fires when loading a single round without the magazine in place. With the magazine in place it slows down the bolt velocity and firing pin inertia and no slam fires.
The biggest cause of slam fires are high primers not seated below flush with the base of the case.
It is recommended to use primers with a cup thickness of .025 with ammunition used in the M16 type rifles.
Read the link below, I had a SKS go full auto but this was caused by a binding firing pin. I'm loading for three AR15 rifles and use Remington 7 1/2 primes and never had a single problem.
CHOOSING THE RIGHT PRIMER - A PRIMER ON PRIMERS
http://www.sksboards.com/smf/?topic=56422.0
Below is a No.41 primer drawing, the cup is thicker in its base and the anvil is shorter. Meaning it takes more force to set off the primer, BUT this type primer was never used before 2001.
Bottom line, the CCI 41 and 34 primers were nothing more than a way to charge the U.S. Government more money for primers and ammunition made at Lake City. And were never used until after 2001 when ATK took over the contract to produce ammunition at Lake City.
And primer sensitivity is governed by cup thickness, the hardness of the brass cup and the height of the primers anvil.
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It's like you're saying "Lake City didn't use M41 primers 20 years ago, so you shouldn't have a slamfire with your 2018 AR, also, don't use M41, use a 0.025'' primer instead, it's recommended for an AR".
Not only is it irrelevant that some M16 of 20 years ago didn't have slamfires with ammos produced in a particular plant compared to the OP's AR15 of unknown origin with his own reloads, then you actually recommend using 0.025'' cup thickness primers, which is exactly what M41 primers are. Did you copy/paste the right post?
Not only is it irrelevant that some M16 of 20 years ago didn't have slamfires with ammos produced in a particular plant compared to the OP's AR15 of unknown origin with his own reloads, then you actually recommend using 0.025'' cup thickness primers, which is exactly what M41 primers are. Did you copy/paste the right post?
The only .223/5.56 ammunition that uses the CCI 41 and 34 primers are made by Lake City and possibly Federal who is owned by ATK.
And the base of the #41 primer is thicker than .025 so look at the mil-spec drawing again. And try not to get bent out of shape, do you think that the Canadian military 5.56 ammunition uses CCI #41 primers.
There is no other ammunition company that uses CCI 41 and 34 primers with their commercial contact ammunition for the military.
Bottom line, the OP had slam fires with the thinner CCI 400 primers with a cup thickness of .020 and now understands why the thicker .025 primer cups are recommended.
And instead of getting hot under the collar and being insulting why don't you do some research like I did on the subject
NOTE, the first ammunition made by Remington for M16 rifle trials testing had the thinner 6 1/2 primers. And there were some slam fire problems, the primers were changed to the 7 1/2 primer and the firing pin was lightened and this fixed the problem.
And the book below which I have covers the development of the M16 rifle and its changes to date. And a few wars and millions of rounds of ammunition were fired "WITHOUT" the CCI #41 primers.
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ive never used anything but standard 400 or usually WW primers before and never had a prob. allways a first time right. the gun was clean and pin fine and free from oils and grease and carbon. this is not my first barn dance ether in the loading department. have loaded for 30 plus years and this is the first time ive ever had a problem like this. one round was put in the mag, mag inserted into the rifle. bolt was locked back. hit the release dropped the bolt and boom. it did not kick out the empty which was weird. after I got my whits about me I dumped the mag and pulled back the bolt and dumped the empty. only the tinyest pin imprint in the primer. stripped the gun, checked it over, all well. loaded another mag full of factory rounds and all was well. so all I can see is I had a sensitive primer? not wishing to have this happen again I thought id see who makes thicker ones
You used a CCI 400 primer with a .020 cup thickness and had a slam fire. Look at the chart I posted with cup thicknesses and pick a thicker .025 cup.
And read the link I posted from sksboards on choosing the right primer.
My choice of primer was simple for the AR15, I used the 7 1/2 Remington primer that was used by Remington when they developed the 5.56 ammunition at Lake City.
You are not the first person to have a slam fire when using the CCI 400 primer or any other primer with a .020 cup thickness.
If you want the added insurance and peace of mind then switch to the CCI #41 primer if you want to.
Bottom line, the point of my postings is there were millions of rounds fired in the M1 Garand, M14 and M16 rifles long before the CCI 41 and 34 primers were even invented.
NOTE, you loaded a single round in your magazine and had a slam fire. And if you had loaded a full magazine the added drag and pressure of the stacked cartridges would have slowed down the bolt velocity. Meaning greatly reducing the chance of a slam fire with lower bolt velocity and firing pin inertia. And this is the reason why the thinner .020 cup primer went off causing the slam fire.
And read the link I posted from sksboards on choosing the right primer.
My choice of primer was simple for the AR15, I used the 7 1/2 Remington primer that was used by Remington when they developed the 5.56 ammunition at Lake City.
You are not the first person to have a slam fire when using the CCI 400 primer or any other primer with a .020 cup thickness.
If you want the added insurance and peace of mind then switch to the CCI #41 primer if you want to.
Bottom line, the point of my postings is there were millions of rounds fired in the M1 Garand, M14 and M16 rifles long before the CCI 41 and 34 primers were even invented.
NOTE, you loaded a single round in your magazine and had a slam fire. And if you had loaded a full magazine the added drag and pressure of the stacked cartridges would have slowed down the bolt velocity. Meaning greatly reducing the chance of a slam fire with lower bolt velocity and firing pin inertia. And this is the reason why the thinner .020 cup primer went off causing the slam fire.
Below photos of thinner cup CCI 400 primers fired in a AR15 rifle, and you can see from the rounded edges of the primer these were not hot loads.
This problem was caused by pushing the case shoulder back too far during sizing and creating too much head clearance.
When the cartridge fired the chamber pressure pushed the primer back over the firing pin and it punched the hole in the primer like a cookie cutter.
Bottom line, there is a reason why the military crimps their primers and uses primers with thicker cups.
Below the chamber pressure forced the anvil out of the hole in the thinner CCI 400 primer.
Below the thinner CCI 400 primers caused high pressure gas leakage and the tip of the firing pin was eroded.
And as I stated before you are not the first person to have problems with CCI 400 primers in the AR15 rifle.
This problem was caused by pushing the case shoulder back too far during sizing and creating too much head clearance.
When the cartridge fired the chamber pressure pushed the primer back over the firing pin and it punched the hole in the primer like a cookie cutter.
Bottom line, there is a reason why the military crimps their primers and uses primers with thicker cups.
Below the chamber pressure forced the anvil out of the hole in the thinner CCI 400 primer.
Below the thinner CCI 400 primers caused high pressure gas leakage and the tip of the firing pin was eroded.
And as I stated before you are not the first person to have problems with CCI 400 primers in the AR15 rifle.
you know I thought bout that, the single round in the mag, letting the bolt travel faster, but then I thought, its no different than the last round in any magfull. part of the prob also may be that the AR is pretty new, return spring is fresh and has lots power in it
If you do not change primers to a cup thickness of .025 after reading all this information and have another slam fire it will be your own fault.
Remington makes the 6 1/2 primer with a cup thickness of .020 and has a warning to not use them with high pressure cartridges like the .223.
PRIMERS AND PRESSURE
http://www.jamescalhoon.com/primers_and_pressure.php
In the course of talking to many shooters, it has become clear to me that the manufacturers of primers have done a less than adequate job of educating reloaders on the application of their primers. Everybody seems to realize that some primers are "hotter" than others and some seem to shoot better for them than others, but few reloaders know that primers have different pressure tolerances.
Back to the main topic: pressure tolerance. I was getting primer piercing before I reached case overloading. I don’t know what prompted me to try CCI 450’s instead of the 400’s which I had been using, but I did. Presto! No more piercing! Interesting!? A primer that has a hotter ignition and yet withstands more pressure! That’s when I decided that it was time to do a dissection of all primers concerned. The chart above shows my results.
By studying the numbers, one can readily see which primers in the small rifle sections will withstand heavy loads. Primer cup diameters are all similar and appear to follow a specification, but check out the cup thickness in the small rifle primers (Dimension "A"). It is obvious that the thicker cups will withstand more pressure. Large rifle primers all appear to have the same cup thickness, no matter what the type. (As a note of interest, small pistol primers are .017" thick and large pistol primers are .020" thick.)
If you are shooting a 22 Cooper, Hornet, or a Bee, the .020" cup will perform admirably. But try using the .020" cup in a 17 Remington and you’ll pierce primers, even with moderate loads.
Considering that cup thickness varies in the small rifle primers, it is obvious that primer "flatness" cannot solely be used as a pressure indicator.
Another factor which determines the strength of a primer cup is the work hardened state of the brass used to make the primer cup. They are made with cartridge brass (70% copper, 30% zinc), which can vary from 46,000 psi, soft, to 76,000 psi tensile strength when fully hardened. Manufacturers specify to their brass suppliers the hardness of brass desired. I was not able to test primer hardness, but an educated guess says that a primer manufacturer would choose a harder brass iIn the course of talking to many shooters, it has become clear to me that the manufacturers of primers have done a less than adequate job of educating reloaders on the application of their primers. Everybody seems to realize that some primers are "hotter" than others and some seem to shoot better for them than others, but few reloaders know that primers have different pressure tolerances.
Back to the main topic: pressure tolerance. I was getting primer piercing before I reached case overloading. I don’t know what prompted me to try CCI 450’s instead of the 400’s which I had been using, but I did. Presto! No more piercing! Interesting!? A primer that has a hotter ignition and yet withstands more pressure! That’s when I decided that it was time to do a dissection of all primers concerned. The chart above shows my results.
By studying the numbers, one can readily see which primers in the small rifle sections will withstand heavy loads. Primer cup diameters are all similar and appear to follow a specification, but check out the cup thickness in the small rifle primers (Dimension "A"). It is obvious that the thicker cups will withstand more pressure. Large rifle primers all appear to have the same cup thickness, no matter what the type. (As a note of interest, small pistol primers are .017" thick and large pistol primers are .020" thick.)
If you are shooting a 22 Cooper, Hornet, or a Bee, the .020" cup will perform admirably. But try using the .020" cup in a 17 Remington and you’ll pierce primers, even with moderate loads.
Considering that cup thickness varies in the small rifle primers, it is obvious that primer "flatness" cannot solely be used as a pressure indicator.
Another factor which determines the strength of a primer cup is the work hardened state of the brass used to make the primer cup. They are made with cartridge brass (70% copper, 30% zinc), which can vary from 46,000 psi, soft, to 76,000 psi tensile strength when fully hardened. Manufacturers specify to their brass suppliers the hardness of brass desired. I was not able to test primer hardness, but an educated guess says that a primer manufacturer would choose a harder brass in order to keep material thickness down and reduce costs.
I have not run into primer piercing with large rifle primers. They are all the same thickness and therefore are not subject to the same misapplication problems. Exceptions can be created if too fast a powder is used in a magnum type case. The
22 Cheetah is a primer piercer with fast powders as Barry and I found out!
What does all this mean to the reloader?
- Cases that utilize small rifle primers and operate at moderate pressures(40,000 psi) should use CCI 400, Federal 200, Rem 6 1/2, or Win SR. Such cases include 22 CCM, 22 Hornet and the 218 Bee. These primers are also used in heavy handguns such as the 9mm., 357, etc. Other cases that use the small rifle primer can use the above primers only if moderate loads are used. Keep to the lower end of reloading recommendations.
- Cases that utilize Small Rifle primers and operate at higher pressures (55,000 psi) should use CCI 450, CCI BR4, Fed 205 and Rem 7 1/2.
- With large rifle primers all being the same thickness, choose a primer that makes the most accurate group, is the shiniest, cheapest or whatever, as they all have similar pressure capabilities.
http://www.jamescalhoon.com/primers_and_pressure.php
In the course of talking to many shooters, it has become clear to me that the manufacturers of primers have done a less than adequate job of educating reloaders on the application of their primers. Everybody seems to realize that some primers are "hotter" than others and some seem to shoot better for them than others, but few reloaders know that primers have different pressure tolerances.
Back to the main topic: pressure tolerance. I was getting primer piercing before I reached case overloading. I don’t know what prompted me to try CCI 450’s instead of the 400’s which I had been using, but I did. Presto! No more piercing! Interesting!? A primer that has a hotter ignition and yet withstands more pressure! That’s when I decided that it was time to do a dissection of all primers concerned. The chart above shows my results.
By studying the numbers, one can readily see which primers in the small rifle sections will withstand heavy loads. Primer cup diameters are all similar and appear to follow a specification, but check out the cup thickness in the small rifle primers (Dimension "A"). It is obvious that the thicker cups will withstand more pressure. Large rifle primers all appear to have the same cup thickness, no matter what the type. (As a note of interest, small pistol primers are .017" thick and large pistol primers are .020" thick.)
If you are shooting a 22 Cooper, Hornet, or a Bee, the .020" cup will perform admirably. But try using the .020" cup in a 17 Remington and you’ll pierce primers, even with moderate loads.
Considering that cup thickness varies in the small rifle primers, it is obvious that primer "flatness" cannot solely be used as a pressure indicator.
Another factor which determines the strength of a primer cup is the work hardened state of the brass used to make the primer cup. They are made with cartridge brass (70% copper, 30% zinc), which can vary from 46,000 psi, soft, to 76,000 psi tensile strength when fully hardened. Manufacturers specify to their brass suppliers the hardness of brass desired. I was not able to test primer hardness, but an educated guess says that a primer manufacturer would choose a harder brass iIn the course of talking to many shooters, it has become clear to me that the manufacturers of primers have done a less than adequate job of educating reloaders on the application of their primers. Everybody seems to realize that some primers are "hotter" than others and some seem to shoot better for them than others, but few reloaders know that primers have different pressure tolerances.
Back to the main topic: pressure tolerance. I was getting primer piercing before I reached case overloading. I don’t know what prompted me to try CCI 450’s instead of the 400’s which I had been using, but I did. Presto! No more piercing! Interesting!? A primer that has a hotter ignition and yet withstands more pressure! That’s when I decided that it was time to do a dissection of all primers concerned. The chart above shows my results.
By studying the numbers, one can readily see which primers in the small rifle sections will withstand heavy loads. Primer cup diameters are all similar and appear to follow a specification, but check out the cup thickness in the small rifle primers (Dimension "A"). It is obvious that the thicker cups will withstand more pressure. Large rifle primers all appear to have the same cup thickness, no matter what the type. (As a note of interest, small pistol primers are .017" thick and large pistol primers are .020" thick.)
If you are shooting a 22 Cooper, Hornet, or a Bee, the .020" cup will perform admirably. But try using the .020" cup in a 17 Remington and you’ll pierce primers, even with moderate loads.
Considering that cup thickness varies in the small rifle primers, it is obvious that primer "flatness" cannot solely be used as a pressure indicator.
Another factor which determines the strength of a primer cup is the work hardened state of the brass used to make the primer cup. They are made with cartridge brass (70% copper, 30% zinc), which can vary from 46,000 psi, soft, to 76,000 psi tensile strength when fully hardened. Manufacturers specify to their brass suppliers the hardness of brass desired. I was not able to test primer hardness, but an educated guess says that a primer manufacturer would choose a harder brass in order to keep material thickness down and reduce costs.
I have not run into primer piercing with large rifle primers. They are all the same thickness and therefore are not subject to the same misapplication problems. Exceptions can be created if too fast a powder is used in a magnum type case. The
22 Cheetah is a primer piercer with fast powders as Barry and I found out!
What does all this mean to the reloader?
- Cases that utilize small rifle primers and operate at moderate pressures(40,000 psi) should use CCI 400, Federal 200, Rem 6 1/2, or Win SR. Such cases include 22 CCM, 22 Hornet and the 218 Bee. These primers are also used in heavy handguns such as the 9mm., 357, etc. Other cases that use the small rifle primer can use the above primers only if moderate loads are used. Keep to the lower end of reloading recommendations.
- Cases that utilize Small Rifle primers and operate at higher pressures (55,000 psi) should use CCI 450, CCI BR4, Fed 205 and Rem 7 1/2.
- With large rifle primers all being the same thickness, choose a primer that makes the most accurate group, is the shiniest, cheapest or whatever, as they all have similar pressure capabilities.
