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Short Barrel 308 Load dev

Zigjib

Private
Full Member
Minuteman
Jul 19, 2014
159
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About to barrel up a 308 with a 12.5" barrel.
Looking for recommendations on a powder that will produce low ES/SD but give me a more complete burn for a shorter barrel than something like Varget.
Any recommendations appreciated.
 
Most people say best powder is best powder independent of barrel length in a bolt gun i think? Could be room here though for some wiggle as ive never run a 308 that short. Or if youre semi, there are other things in play.

I will say a 3030 run at 13 inches with a 155smk shot best with the same powder that it liked before it went sbr. Had to tweak the load about .5g to keep same group size, but otherwise same.

Maybe something slightly faster than normal to be less flashy or blasty? THAT could definitely be a consideration worth looking into. That stick gonna be blasty lol.

How about bullet choice? Light medium or heavy weight? Id think that will drive powder choice the most.

Rifle info, bullet info, available options for components and purpose/goal will be helpful and likely garner better responses.
 
Viht 135 w/ 155 grainers should do the trick somewhere between 41 to 43 grns.. WORK UP to it !!!
 
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I could run some numbers on GRT if I had a starting point. Do you have an idea of powder, projectiles, brass, etc that you're looking to use? Do you have some stuff on hand?
 
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About to barrel up a 308 with a 12.5" barrel.
Looking for recommendations on a powder that will produce low ES/SD but give me a more complete burn for a shorter barrel than something like Varget.
Any recommendations appreciated.
Wow 12.5" going to be a flame thrower . The fastest burn powder, I used for .308 win and lightweight bullets, has been ( Reloader10x ) .
.
 
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I could run some numbers on GRT if I had a starting point. Do you have an idea of powder, projectiles, brass, etc that you're looking to use? Do you have some stuff on hand?
I've run some numbers on GRT around AR2206H (local powder) and have pretty much settled on that but I thought I would throw it out there and see if there was anything better. there's a lot of brands and types in the folders and it's a lot to sit there and slowly go through all the powders. Was hoping someone could narrow it down a bit.
Components i'm using are;
178gr ELD-M
308 Lapua Brass
FGMM 210m primers
COAL is locked to 2.8" as i'm using AR10 Magazines.
 
Wow 12.5" going to be a flame thrower . The fastest burn powder, I used for .308 win and lightweight bullets, has been ( Reloader10x ) .
.
Thanks i'll look into it. Yeah i'm looking forward to seeing waht the 308 can do at that short of a barrel, but yeah, the flash and bang is going to be brain shaker
 
I'll narrow it down by powders I've seen available online the last few weeks. For inputs I just took volume I found online for Lapua 308WIN (56.30grains - 3.64g), Set max length to 2.80, barrel to 12.5", Hornady ELD-M.. These are all below the "working to max pressure warning" and considered "safe" on GRT. You'll need to take your own measurements, of course.
Accurate 2230 - 38gn 2162fps [8lb for sale here in PX in Kansas]
Alliant RL15 - 42gn 2157fps
Alliant AR Comp - 39gn 2162fps
Shooters World Match Rifle - 42gn 2184fps
Hodgdon H335 - 41gn 2172fps
Hodgdon H4895 - 40gn 2184fps
Hodgdon Varget - 42gn 2182fps
Hodgdon CFE223 - 44gn 2176fps

Hope this helps
 
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About to barrel up a 308 with a 12.5" barrel.
Looking for recommendations on a powder that will produce low ES/SD but give me a more complete burn for a shorter barrel than something like Varget.
Any recommendations appreciated.
Bullet Wt. would help ? Some of the older manuals listed RL-7 with bullets up to 150 gn. The newer manuals list H 322 and IMR 3031
 
I haven't loaded any just yet, but Im going to try H335 and 8208XBR with 125 grain SST out of my 13" SCAR. Im looking for something similar to MK319. I hear H335 is dirty, but lots of praise for 8208XBR. Im not sure those are the best choices for 178grain though. Id probably stick with TAC
 
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I just looked at XBR 8208 this morning. I just haven't seen that powder lately which means its probably coming around again soon.
XBR 8208 - 40gn - 2174fps
you mentioned complete burn in your OP. That combo burns about 90% while others I listed have a more complete burn for the same speed and not push unsafe pressures.
Looks like TAC will work if you have it on the shelf. Just not the "best" choice according to GRT.
TAC - 42gn - 2186 90% burn
 
I'm running 11" 10Twist 308win Bolt Gun with a Dominus-SR.

H332 - 135g SMKs @ 2700fps
H332 - 155g Hybrids @ 2600fps

The 155g load is noticeably quieter and produces better SDs. I'd say it's likely that the heavier bullet allows for a more complete burn which lends to tighter SDs. I never tried any other powders for this rifle, but I'd presume anything slower would cause fairly noticeable fireballs, secondary ignition in the suppressor, and massive SDs.

Run what you brung tho.
 
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Used to be a member here in CO that ran a 12.5” AR in .308.
His posts on this could be useful


@jasonfaz if my memory serves….. (go easy, Im old)
 
I would try Benchmark for the 150 gr its a faster powder then say XBR or Varget .i use it in my bolt guns 43.5 grs i get them going around 2900.
 
Thanks i'll look into it. Yeah i'm looking forward to seeing waht the 308 can do at that short of a barrel, but yeah, the flash and bang is going to be brain shaker

Are you approaching this with the goal of:
a) reducing flash and blast, accepting some loss in velocity to do so?
or
b) are you hoping to gain back some velocity by switching to a powder with "more complete burn?

If it's b), then forget about it, it doesn't work that way until the barrel is WAY shorter than that.
If it's a) then one of the faster stick powders will be your huckleberry, and avoid the ball powders. I'd probably look to Rl-10x first.
 
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