For some time, I wanted to see how different #41 primers acted compared to 450’s. In my previous chronograph testing, it seemed the #41’s tended to give higher SD’s, but none of my data was actually apples to apples.
So, I decided to load some up – identical, except for the primers. And since I also had some CCI 400’s laying around, I said what the heck, I’ll throw them into the test too.
The Bullet: Sierra’s 65gn SBT, product #1395. This is my chosen zombie apocalypse bullet (not being a rifle guy, I don't really know if it's a good choice for that application; but, it's the one I've chosen) and the only one I intend to use the #41’s with. So, it seemed the logical choice. Seated to 2.240” OAL.
The Brass: Lake City, vintage “21,” and “22.” Trimmed to 1.750.” Primer pockets swaged, of course. Processed with RCBS Small Base dies. No flair (it’s a boat tail) and no crimp.
The propellant: Accurate Arms 2230. 24.0 grains. I did not weigh each charge individually. They were all dropped from an RCBS Uniflow hopper with the small drum (presumably more accurate than the large) and the same setting for all rounds.
The firearm: An AR-15 with a 556 upper, 16” barrel. 1:7 twist.
I tested 10 rounds of the 400, 10 of the 450, and 10 of the #41's. Then repeated, for 20 rounds each total.
CCI-400: 2743 f/s, 46.01 SD.
CCI-450: 2723 f/s, 21.50 SD.
CCI-#41: 2822 f/s, 45.96 SD.
I guess the first eyebrow raiser is the fact that the “non-magnum” CCI 400 produced a higher velocity than the “magnum” CCI 450. The other eyebrow raiser was that the CCI #41 delivered 99 f/s more than the 450 when they’re presumably the same mixture, with a different anvil. That’s a big difference. I did expect the SD to go up with the #41’s, but it didn't go up as much as I thought.
No slam-fires, btw.
This is just data I’ve wanted to know for some time, and now I have it. Just thought I’d share. Feel free to chime in with your thoughts.
So, I decided to load some up – identical, except for the primers. And since I also had some CCI 400’s laying around, I said what the heck, I’ll throw them into the test too.
The Bullet: Sierra’s 65gn SBT, product #1395. This is my chosen zombie apocalypse bullet (not being a rifle guy, I don't really know if it's a good choice for that application; but, it's the one I've chosen) and the only one I intend to use the #41’s with. So, it seemed the logical choice. Seated to 2.240” OAL.
The Brass: Lake City, vintage “21,” and “22.” Trimmed to 1.750.” Primer pockets swaged, of course. Processed with RCBS Small Base dies. No flair (it’s a boat tail) and no crimp.
The propellant: Accurate Arms 2230. 24.0 grains. I did not weigh each charge individually. They were all dropped from an RCBS Uniflow hopper with the small drum (presumably more accurate than the large) and the same setting for all rounds.
The firearm: An AR-15 with a 556 upper, 16” barrel. 1:7 twist.
I tested 10 rounds of the 400, 10 of the 450, and 10 of the #41's. Then repeated, for 20 rounds each total.
CCI-400: 2743 f/s, 46.01 SD.
CCI-450: 2723 f/s, 21.50 SD.
CCI-#41: 2822 f/s, 45.96 SD.
I guess the first eyebrow raiser is the fact that the “non-magnum” CCI 400 produced a higher velocity than the “magnum” CCI 450. The other eyebrow raiser was that the CCI #41 delivered 99 f/s more than the 450 when they’re presumably the same mixture, with a different anvil. That’s a big difference. I did expect the SD to go up with the #41’s, but it didn't go up as much as I thought.
No slam-fires, btw.
This is just data I’ve wanted to know for some time, and now I have it. Just thought I’d share. Feel free to chime in with your thoughts.