6.5 PRC slow powders and light bullets?

The performance of "Swiss" Nitrochemie powders is amazing. That is why General Dynamics got their chemist to come to North America, temporarily, and improve the performance of their powders. The 2000MR and 4000MR are examples. Reloader 26, manufactured in Switzerland by Nitrochemie, is imported by Vista Outdoors, under the Alliant brand. From the Quickload data provided by IHFarmer07, note that the second powder on the list that you might actually get enough in the case, Swiss 70, is also a top performer but has a faster burn rate than R-26. When selecting a powder using quickload, you want to get enough in the case to reach the pressure you selected. 64K is likely the maximum and I might choose 63K or 62K in the program, for longer case life, but I reload and shoot a lot. Second, look to see that you burned all of the powder, or nearly all, in the barrel. Work up slowly, Quickload is a computer program, primers are not a variable you can choose, so expect that you reach unfavorable pressures before the program predicts.
 
The performance of "Swiss" Nitrochemie powders is amazing. That is why General Dynamics got their chemist to come to North America, temporarily, and improve the performance of their powders. The 2000MR and 4000MR are examples. Reloader 26, manufactured in Switzerland by Nitrochemie, is imported by Vista Outdoors, under the Alliant brand. From the Quickload data provided by IHFarmer07, note that the second powder on the list that you might actually get enough in the case, Swiss 70, is also a top performer but has a faster burn rate than R-26. When selecting a powder using quickload, you want to get enough in the case to reach the pressure you selected. 64K is likely the maximum and I might choose 63K or 62K in the program, for longer case life, but I reload and shoot a lot. Second, look to see that you burned all of the powder, or nearly all, in the barrel. Work up slowly, Quickload is a computer program, primers are not a variable you can choose, so expect that you reach unfavorable pressures before the program predicts.
Thank you for enlightening us on some of these powders and expanding on my posts!
 
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@IHFarmer07 : I'm curious as to whether these powder rankings hold for an 18" barrel.

I think common internet lore (potentially erroneously) suggests that faster powders should be used in shorter barrels, but I have heard from others that the same powders are relevant for a given projectile weight regardless of whether longer or shorter barrels.
 
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So it is the same powders providing best velocity for a given projectile, regardless of barrel length.

I can't count the number of times someone has chimed in that a faster powder should be used for the same bullet due to a shorter barrel (eg thinking that more of the "faster" powder will be burned) ?

This is really interesting!
Lol 🤷🏻‍♂️🤷🏻‍♂️. It sure is, I'm in your boat thinking the same.
 
I went out today with two rifles in 6.5 PRC using ADG brass, a case I picked at random was 67gr of h2o.

Temp was 52*, and 3 round average velocities at the muzzle with 123gr eldm, imr4350, 210gm primer and COAL 2.863" no pressure signs from 50-52.5gr in my rifles.

---------M18----Bergara
50gr----2720-----2812
50.5gr--2732-------**
51gr----2765------2845
51.5gr ---**-------2922
52.5----2868------2949

Nothing extraordinary in sd or groups, some were sub .5 moa but most were between .6 and .9moa at 100 yards. Not the velocities I want, both barrels are 24" and have 60 or so rounds through them so still breaking in. I'll see what I can get to when I start to see pressure signs, and maybe work up some loads with RL23.
 
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Lol 🤷🏻‍♂️🤷🏻‍♂️. It sure is, I'm in your boat thinking the same.

@IHFarmer07 — would you humor me and rerun the 18" data using 69grain h2o capacity?

It just isn't making sense to me why R26, with nearly the same burn rate as H1000 (and slower than some of the others) would produce such runaway results even against the faster powders. I'm wondering if limited case capacity is skewing the results, and QL is having to compromise the results due to powder density.
 
@IHFarmer07 — would you humor me and rerun the 18" data using 69grain h2o capacity?

It just isn't making sense to me why R26, with nearly the same burn rate as H1000 (and slower than some of the others) would produce such runaway results even against the faster powders. I'm wondering if limited case capacity is skewing the results, and QL is having to compromise the results due to powder density.
I sure can, it'll have to be later tonight?.....I'm at work now and don't have my computer or time. I'll do @alaskan9974's updated figures too.

You all have 8 twist barrels? I'm pretty sure there is an option for twist also......I'm thinking those figures above was based on 7 twist(it's what I have)........I think, not 100% sure. Sorry if I'm right in it being set for 7 twist. I'll look in to it tonight
 
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I sure can, it'll have to be later tonight?.....I'm at work now and don't have my computer or time. I'll do @alaskan9974's updated figures too.

You all have 8 twist barrels? I'm pretty sure there is an option for twist also......I'm thinking those figures above was based on 7 twist(it's what I have)........I think, not 100% sure. Sorry if I'm right in it being set for 7 twist. I'll look in to it tonight

I am running 1:8, but I don't think it would make a meaningful difference--wanted to minimize effort on your part.

I have really been scratching my head about the prior results not correlating with burn rates, and I am hoping the case capacity issue provides some insight.
 
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