short barrel 308 powder?

[SpeedyR]

will start working on some loads for a 308 AR piston gun. PWS piston system with a 16" barrel. I had assumed a quicker burning powder so that there's not a lot left by the time the bullet exits the barrel? But what's a powder like Varget doing with a 16" barrel?

I'll be shooting mostly 175gr SMK to start with, may shoot some Amax or if anyone else has a suggestion for longer range I'm all ears. I've got a bunch of LC that I'm in the process of prepping, and have a few hundred SMK's to get me started. I"ve got a variety of powders from experiments over the years and don't mind trying something new if needed. Seems I saw good numbers from CFE223 in the 308 recently. Ideally 100-700 yards range but would like something I can stretch out to 1k if I can find somewhere to shoot it that far.

trying to keep velocity up, flash down, and not excessive pressure spikes. lol.

 

[Twitch2120]

You don't have the barrel to make slow powders like cfe and mr2k burn fully. While it won't be a bad thing to try you will probably have better luck with faster powders like either 4895, 8208 or perhaps 4064.

 

[Quacker]

I can't comment on the 16" barrel but I have been trying to get the highest velocity possible with my 20". I think the slower burning powders are actually gonna give you the highest velocity without exceeding pressure. The faster burning powders will hit the high pressure end before you get the velocity you want.

Go to
http://www.hodgdonreloading.com/
and plug in some different powders for a 175 grain projectile. Compare your fast burning powders with the slow ones and see the pressure vs velocity difference. I assume the velocity is really what you're after??

It might also be worth trying it in the real world with a chrono. Id be interested to see the results.

 

[draftpick]

power pro 200 powder claims to get 150-200 fps with heavy grain 308 pills.

 

[SpeedyR]

from what I've read everyone says to just stick with the tried and true powders. I'll load up some Varget and maybe RL15 rounds similar to FGMM's and see how they shoot. I've got one of the new Caldwell chronographs, and should have my mount for the scope next week. then just make time to get to the range!

 

[Twitch2120]

power pro 200 powder claims to get 150-200 fps with heavy grain 308 pills.

And it claims correctly when you have enough barrel to burn it in. 16" is short for a 308, powder will be burning on exit.

I do 2800 using pp2k 185 juggernauts out of a 26" tube. Btw

 

[flyingfrog509]

I was playing with CFE223 out of an 18" Rhino barrel w/brake and have had good results. Obviously check the manuals, make sure you don't blow yourself up, etc, etc.

Out of an Areo AR10 upper, Rhino 18" 1-10 twist barrel...
Federal brass, 210 primers, CFE223 at 48grains, 168SMK - 5 shot group .998 outside 2 outside, .690 center 2 center at 100 off a sand bag w/10x SWFA scope

I didn't have any luck with 175's yet but I'm early in load development. Federal Gold Match 168 shoot right at MOA also where the 175 factory loads I tried seemed to open up the groups a bit as did the 150-155 loads. Didn't take the chrono out yet so I don't have any speed data yet.


I'm not sure if that will ever stretch out to 1000 but I know it is good to 600 yards on paper. I think trying to shoot 1000 yards out of a 16" barrel is going to be hard. We never could get there with my son's 20" SPS tactical. Good luck, be safe, share your results.

 

[1006]

Look at pistol loads for the 308. Often the loads are geared for a 15inch barrel.

I use Hodgdons 223 pistols loads for my 16 inch barrel, and velosities are very consistent.

 

[rosewood]

from what I've read everyone says to just stick with the tried and true powders. I'll load up some Varget and maybe RL15 rounds similar to FGMM's and see how they shoot. I've got one of the new Caldwell chronographs, and should have my mount for the scope next week. then just make time to get to the range!

I use RL-15 in my 7-30 waters 14" contender and it seems to burn completely in the 14". I would imagine 16" in a .308 would do well also. From my experience though, the shorter barrel you use, the faster powder you need to burn completely and reduce muzzle flash and boom. Varget is pretty dang near close to RL-15 in burn rate so the results should be similar.

The trick is finding the bullet/powder combination for your given barrel length that gives you the highest velocity with least muzzle flash/report. Ideally, the powder would burn up completely at the exact point of exiting barrel, not sure how to figure that one out though.

 

[Twitch2120]

I use RL-15 in my 7-30 waters 14" contender and it seems to burn completely in the 14". I would imagine 16" in a .308 would do well also. From my experience though, the shorter barrel you use, the faster powder you need to burn completely and reduce muzzle flash and boom. Varget is pretty dang near close to RL-15 in burn rate so the results should be similar.

The trick is finding the bullet/powder combination for your given barrel length that gives you the highest velocity with least muzzle flash/report. Ideally, the powder would burn up completely at the exact point of exiting barrel, not sure how to figure that one out though.

Quickload and experimenting.