Shavox,
Your loads should be easy shooting. The common 47 grain charge of modern canister grade IMR4895 produces about the ballistics of the old M72 National Match ammo, which used a 173 grain bullet and which the Garand handles just fine. With your 150 grain bullet, you are treating the old girl pretty gently. M2 Ball was loaded to 2740 fps at 26 yards (78 feet), which translates to about 2802 fps actual muzzle velocity out of the pressure test barrel. You should get there with about 48 grains of modern canister grade IMR 4895. It's a pretty close match to the average performance over the years of the bulk grade 4895 used in NM ammunition.
As is often the case with this member, he states things as fact without doing his homework, resulting in a mix of true and untrue things.
From a phone conversation I had with CCI: the CCI #34 primer uses the same cup and priming mix charge as their #250 large rifle magnum primer, but, as mentioned earlier, the anvil is different. It's tripod legs are spread at a wider included angle than the anvils used in the #250 have, so the anvil is less rigid and requires a higher energy firing pin strike to ignite. They chose how much harder to make the firing pin strike based on the military primer sensitivity specification shown below. This is a table for an H (height) test in which a weight (110 grams, IIRC) is dropped onto a firing pin to act as its hammer. The primers are seated in an empty case held in an upside down shell holder. The percent failures to fire and successes in firing are recorded at half S intervals and the skewness calculated and it is not allowed to exceed a certain number (±0.787 IIRC). But the bottom line idea behind this is they should not fire when the weight is dropped at the lowest height and should always fire when it is dropped from the top height.
![attachment.php](https://thefiringline.com/forums/attachment.php?attachmentid=105182&stc=1&d=1496930186"]https://thefiringline.com/forums/attachment.php?attachmentid=105182&stc=1&d=1496930186)
Note that CCI boasts its #250 primer is more sensitive than some others on the market, so this is probably why they decided to issue one with the sensitivity reduced to that of military #34 primers. Note, however, that other than the sensitivity, it is not a military primer. The same methods apply to their #41 small rifle primer, which is, other than the anvil, like a #450.
Federal makes a military sensitivity version of their 205M small rifle standard strength primer called the 205MAR. In their case, they told me the anvil and mix are the same, but the cup is thicker to achieve the desired sensitivity.
The Russian Tula plant makes what they call a NATO spec primer. I don't know what sensitivity control method they use.
Your loads should be easy shooting. The common 47 grain charge of modern canister grade IMR4895 produces about the ballistics of the old M72 National Match ammo, which used a 173 grain bullet and which the Garand handles just fine. With your 150 grain bullet, you are treating the old girl pretty gently. M2 Ball was loaded to 2740 fps at 26 yards (78 feet), which translates to about 2802 fps actual muzzle velocity out of the pressure test barrel. You should get there with about 48 grains of modern canister grade IMR 4895. It's a pretty close match to the average performance over the years of the bulk grade 4895 used in NM ammunition.
T. O'Hier said:
As is often the case with this member, he states things as fact without doing his homework, resulting in a mix of true and untrue things.
From a phone conversation I had with CCI: the CCI #34 primer uses the same cup and priming mix charge as their #250 large rifle magnum primer, but, as mentioned earlier, the anvil is different. It's tripod legs are spread at a wider included angle than the anvils used in the #250 have, so the anvil is less rigid and requires a higher energy firing pin strike to ignite. They chose how much harder to make the firing pin strike based on the military primer sensitivity specification shown below. This is a table for an H (height) test in which a weight (110 grams, IIRC) is dropped onto a firing pin to act as its hammer. The primers are seated in an empty case held in an upside down shell holder. The percent failures to fire and successes in firing are recorded at half S intervals and the skewness calculated and it is not allowed to exceed a certain number (±0.787 IIRC). But the bottom line idea behind this is they should not fire when the weight is dropped at the lowest height and should always fire when it is dropped from the top height.
Note that CCI boasts its #250 primer is more sensitive than some others on the market, so this is probably why they decided to issue one with the sensitivity reduced to that of military #34 primers. Note, however, that other than the sensitivity, it is not a military primer. The same methods apply to their #41 small rifle primer, which is, other than the anvil, like a #450.
Federal makes a military sensitivity version of their 205M small rifle standard strength primer called the 205MAR. In their case, they told me the anvil and mix are the same, but the cup is thicker to achieve the desired sensitivity.
The Russian Tula plant makes what they call a NATO spec primer. I don't know what sensitivity control method they use.
