Conflicting load data for 308win?

[Potss]

Looking to optimize two loads for velocity above all else in a 16in AR10: Hornady 150gr Interlocks, and Sierra 155gr Matchkings. Not worried about temp sensitivity in this application. Using Lapua brass and CCI BR2s, but I'm stuck on the powders to test. I've check several reloading manuals and they all seem to give different results for which powder would yield the best velocity. Add internet results to that and it is just all over the map, with a lot of conflicting data (even in the manuals). Ideally I'd just test them all, but I don't have that kind of time or money to throw into this right now.

Here is a list of powders that manufacturers, various manuals, and some well respected posters have put at the top of their lists for velocity in this bullet weight range:

CFE 223, Alliant Power Pro 2000-MR, Tac, Accurate 2520, N540, N550, AR2208, Varget, RL15, Win 748, BLC2, Norma 202, IMR4064, H4895/IMR4895, Superformance, LeveRevolution, H322, IMR 3031, AR Comp, 8208, Xterminator.

I bolded the three that showed up most frequently.

So folks, if you were going to choose 2-3 of the above powders (or any really) to try to work up the fasted load you could for those 150-155gr bullets, what would you choose?

 

[Potss]

That is correct, I have a superlative arms adjustable gas block, and can run suppressed or unsuppressed. So I'm not worried about port pressure or brass much.

Which of those powders does Lyman say gets them going fastest?

 

[Rhed]

With a 16” barrel, velocity is reduced then that what’s recorded on data. Most data recorded were tested on barrels 20” or more. So the best thing is to work up, chrono, find the most accurate load rather then speed. A good place to start is go to the bullet manufacturer website. And find the most accurate load recorded and go from there.

 

[918v]

You don’t care about temp stability but you care about max velocity. Are you making a grenade?

 

[308pirate]

You don’t care about temp stability but you care about max velocity. Are you making a grenade?

Maybe he's working up some loads for winter shooting? Maybe he lives in a place without huge swings between winter and summer temps.

Not everything is black and white.

 

[Potss]

308pirate is right on the money. I said I'm working up loads I just want to choose a few powders that are likely to give the best velocity from a 16in AR10 with the two projectiles listed above (150gr & 155gr).

I still intend to ladder test and find a node, I just want to choose powders that are likely to yield the best velocities when I do, because as I said I cannot afford the time or money to test all 22 powders listed.

This is a niche use case, but I figured I'd ask and maybe get some good info.

 

[Rhed]

308pirate is right on the money. I said I'm working up loads I just want to choose a few powders that are likely to give the best velocity from a 16in AR10 with the two projectiles listed above (150gr & 155gr).

I still intend to ladder test and find a node, I just want to choose powders that are likely to yield the best velocities when I do, because as I said I cannot afford the time or money to test all 22 powders listed.

This is a niche use case, but I figured I'd ask and maybe get some good info.

I have a MR762 which is 16.5, 1:11 . I have had best results with 43.8 of Varget, 168 gr Hornady match, 1/2 or under (consistently, BR shooting) out to 100. I’m gonna try experiment with a slower burning powder too like CFE 223..

 

[918v]

If you work up a winter load in the summer with an unstable powder it won’t be accurate. Furthermore, if your powder is inverse sensitive then your load will have pressure issues in the cold.

It is always best to use a stable powder if available and not worry about 50 FPS.

Just use Varget or 8208 and be happy.

 

[bfglowkey]

Varget +1
IMR 4064
TAC

In order or ease of development and speed accounted for. Pure speed...CFE223 or BLC2 but finiky