@Zero333 if you have chance, could you run the same comparison for the PRC case? Thank you in advance! Appreciate your help on this
Yes the 284 parent case and 6.5 PRC case is so close, it's hardly noticeable. I load for both and these are nearly twins. Considering a 25-284 in the near future over a 25 CM. I believe it will certainly outperform the CM performance in a 28" barrel.The two cases; 6.5x284 and the 6.5 PRC have very similar case capacities. The handicap is the barrel length related to the powders needed for the velocity allowing the 6.5 Creedmoor to look nearly as good. You can adjust the powders for those shorter barrels but the difference is magnified when the barrels are longer. Yes, the Creedmoor is efficient but it will not keep up with either of the other cartridges with longer barrels.
I have a 22” barrel on a 25-06. It does hurt the velocity and it has a TON on muzzle blast. I wouldn’t think the 25-284 would be much different.
I'm not doubting your data as I'm sure it's very accurate but we know velocity means nothing without accuracy. For the 25 CM, the accuracy node seems to be around 2940-2970. Push it faster and groups seem to diminish. Two local range shooters here at my private range shoot a 25-284. One with a 24" and the other a 28" barrel. Both guns built for different purposes. Their best accuracy is in the 3125-3150 range. This is with the 131 grain Ace. Looking at their info, it puts those numbers between the two at a very different place. Talking to a few other guys on forums that shoot the 284 parent see their best accuracy near 3200 fps. All using H4831sc powder. This appears to put the two at around 200 fps different. While it may not be huge, it's certainly why the guys going to an ackley version of a cartridge do it. I'm undecided which way I'll go. May wait for the 257 Blackjack reamers or may go with a 25-284. It'll basically come down to which size action I want. It will definitely be one of the two tho.I just compared the 25 CM vs 25-284 with the same 120 gr bullet, at the same 60,000 psi and the same amount of bearing surface inside the case neck...
25 Creedmoor compared to 25-284 is...
20" is 90 fps slower
22" is 90 fps slower
24" is 95 fps slower
26" is 110 fps slower
28" is 115 fps slower
30" is 115 fps slower
That's kind of a general average.
This is all in line with my findings as well. I have nodes at 3080ish, 3150-3160, and 3200. This is from a 257AI not a 25-284, but same bullet and powder capacity. Norma MRP, H100V, 4000-MR, H4350 all work great. And yes, with heavier bullets, a longer action and correct throat length the 257AI is considerably more powerful that the standard ‘Bob.I'm not doubting your data as I'm sure it's very accurate but we know velocity means nothing without accuracy. For the 25 CM, the accuracy node seems to be around 2940-2970. Push it faster and groups seem to diminish. Two local range shooters here at my private range shoot a 25-284. One with a 24" and the other a 28" barrel. Both guns built for different purposes. Their best accuracy is in the 3125-3150 range. This is with the 131 grain Ace. Looking at their info, it puts those numbers between the two at a very different place. Talking to a few other guys on forums that shoot the 284 parent see their best accuracy near 3200 fps. All using H4831sc powder. This appears to put the two at around 200 fps different. While it may not be huge, it's certainly why the guys going to an ackley version of a cartridge do it. I'm undecided which way I'll go. May wait for the 257 Blackjack reamers or may go with a 25-284. It'll basically come down to which size action I want. It will definitely be one of the two tho.
What twist did you end up going with?Decided on the 25-284. I have pounds of lapua 6.5-284 brass. Can't see buying new brass. 24" Bartlein CFW barrel. Rem LA, Iota Kremlin stock, Leupold VX5 HD 3-15 firedot. Getting close. Everything here waiting on gunsmith to greenlight the project. I'll post results.
7.5. Hoping the 24 inch barrel won't handicap me muchThis is all in line with my findings as well. I have nodes at 3080ish, 3150-3160, and 3200. This is from a 257AI not a 25-284, but same bullet and powder capacity. Norma MRP, H100V, 4000-MR, H4350 all work great. And yes, with heavier bullets, a longer action and correct throat length the 257AI is considerably more powerful that the standard ‘Bob.
What twist did you end up going with?
It shouldn’t. I’m running a 25” barrel for my speed data. I will probably go 27” next time to bring pressure down a little bit for the same velocities. That will put me at ~30” with a brake.7.5. Hoping the 24 inch barrel won't handicap me much
Interesting!This is all in line with my findings as well. I have nodes at 3080ish, 3150-3160, and 3200. This is from a 257AI not a 25-284, but same bullet and powder capacity. Norma MRP, H100V, 4000-MR, H4350 all work great. And yes, with heavier bullets, a longer action and correct throat length the 257AI is considerably more powerful that the standard ‘Bob.
What twist did you end up going with?