I have just swapped to 6CM on my new build and I have 1400 400s on hand and 3k 41s on hand. I should be running LRP since I have several of those and use these in my ARs but want to give srp a try. Out of the 2 what would you suggest? I'm leaning towards the 400s but haven't really tried the 41s much at all just found them when the scare started. If more info is needed I shoot long range out to a mile and will be using H4350 and Berger 105 hybrids and Hornady 108 elb-m.
- Thread starter Andrew863
- Start date
My vote would be 450s/41s for the thicker cup if you are trying to push pressure.
400s are for low pressure rounds, 22 hornet etc. Some use them in 223 but they are more prone to excessive cratering and puncturing.
Youre going to want to use the thicker cupped 450 or 41 primers to deal with the high pressures.
What action? With a large .078 firing pin commonly found in rem700 its too big of a hole in the bolt face for the small primer material to adequately support and youll find you get popped primers which is no bueno. The large primers are to go to there. If you have a bushed bolt or a custom action with a small .062 pin then the small primers will do well.
Youre going to want to use the thicker cupped 450 or 41 primers to deal with the high pressures.
What action? With a large .078 firing pin commonly found in rem700 its too big of a hole in the bolt face for the small primer material to adequately support and youll find you get popped primers which is no bueno. The large primers are to go to there. If you have a bushed bolt or a custom action with a small .062 pin then the small primers will do well.
This. I'm having issues with the 400s cratering/flowing with hotter loads. No problems thus far with 41s, 450s, or Fed 205s.
ETA: the load in had issues with is 40.2gr RL16 & 112gr MatchBurners. I didn't have a problem with 41.4gr H4350 & 110gr A-Tips. Rifle is a 24" & 27" 6CRD AI.
40.2gr RL16, 112 gr MatchBurner, Lapua SRP brass, CBOL: 2.205" 0.040" off the lands. Primer test produced the following:
CCI 400 AVG: 3046 ES: 16 SD: 8.1
CCI 41 AVG: 3048 ES: 30 SD: 10.3
CCI 450 AVG: 3057 ES: 46 SD: 16.7
FED 205 AVG: 3048 ES: 24 SD: 8.8
Had I reworked the load with each different Primer, I'm sure I could've gotten these numbers down. It was just a quick test as I was in a rush to find a replacement for the 400s.
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Zermatt arms origin. Seems like most people agree to run the 41s.
The origin will handle small primers just fine (but 400s are still thin and can pop) so yeah, the consensus will be 41s
Ive got an origin 6 creed, youll like it.
I use 400 in pistol ammo. I'd use the 450s if forced to but I would have bought LRP 6CM brass to start with.
I actually went the other direction, and converted to all SRP a few years back. I’ve shot both 450s and 41s in Lapua 6.5 CM brass with no issues, other than an overlarge firing pin hole on my original Bergara B14 bolt. A drop-in Premier bolt fixed that.
Yes, an issue that is well-known in the industry already, has already been addressed as a non-concern for OP in this thread, and has even been addressed by Bergara too; their newer standard B14 bolts have a smaller firing pin for this exact reason, I just have an older one from back when, before they and everyone else figured it out.
Why are you sharing this information with me? I don't care what you do.
