powder for 18" .308 ?


PDA






redclay
September 14, 2011, 09:22 AM
I am reloading for a DPMS Lr 308b with 18" barrell. Wondering what powders would you experienced guys use. Have been loading Varget and my groups are not what I think they should be. Any recommendations?

If you enjoyed reading about "powder for 18" .308 ?" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
MtnCreek
September 14, 2011, 09:29 AM
4895 (IMR or H) or Reloader 15

Sin City Shootist
September 14, 2011, 01:08 PM
Yup 4895 works great. I use Tac because of the price and it seems to meter pretty good and the burn rate is real close to 4895. I love Re-15 but it maybe to slow of a powder for a gas gun unless you load it light. On my FNAR Re-15 powder is still burning when it hit the gas port. You shouldn't really use powder slower then IMR 4064 on a gas gun, just my opinion.

243winxb
September 14, 2011, 03:53 PM
Another DPMS Lr 308b. Are you using small base dies to reload? Just wondered as 3 other posters had a problem using standard dies. IMR 4895 works well for 308 win.

MEHavey
September 14, 2011, 04:40 PM
You need a faster powder than is normaly used if you want good optimal velocities

Cartridge : .308 Win.
Bullet : .308, 150, Sierra FMJ BT 2115
Cartridge O.A.L: 2.800 inch
Barrel Length : 16.5 inch
Matching Maximum Pressure: 54,000 psi

Case Fill: ≥ 90% ≤ 105% (full case/little compression)
Burn: ≥ 95%
Limited to commonly-available powders

IN ORDER:

Type WT(gr) fill(%) vel(fps) Pmax(psi) Burn(%)
IMR 3031 43.9 101 2,654 54,000 100
Winchester 748 46.5 93 2,641 54,000 98
IMR 4895 46.5 100 2,637 54,000 95
Hodgdon BL-C2 48.5 96 2,634 54,000 97
Accurate 2495 44.4 101 2,626 54,000 100
Accurate 2520 47.0 98 2,623 54,000 98
Hodgdon H4895 45.0 97 2,614 54,000 96
Ramshot TAC 45.6 92 2,603 54,000 97
Hodgdon H322 42.1 94 2,602 54,000 99
Vihtavuori N540 47.1 101 2,600 54,000 99
Vihtavuori N530 43.6 94 2,595 54,000 97
Vihtavuori N140 45.6 100 2,583 54,000 99
Accurate 2460 45.6 92 2,582 54,000 98
Alliant RL-12 44.1 93 2,573 54,000 99
Accurate 2230 44.7 90 2,572 54,000 98
Alliant RL-10x 39.7 91 2,571 54,000 100
Hodg Benchmark 43.0 94 2,550 54,000 97
Vihtavuori N133 42.1 99 2,539 54,000 100
Vihtavuori N130 40.5 94 2,527 54,000 100
ACHTUNG -- NOTICE -- ATTENTION
Take These as Suggested Powder Options Only.
Refer to loading manuals for starting loads.

Sin City Shootist
September 14, 2011, 06:50 PM
Another DPMS Lr 308b. Are you using small base dies to reload? Just wondered as 3 other posters had a problem using standard dies. IMR 4895 works well for 308 win.

I bought 1000 rounds of once fired LC brass and I had to small base full length every single one of those pieces of brass before they would feed in my gun. Come to find out they were fired from a machine gun which has a lot looser clearances. After that I've been using a Lee collet neck die and they feed just fine.

velocette
September 14, 2011, 09:44 PM
With my DPMS LR 308B, 18" barrel, I got my best accuracy using 41 gr of
IMR 4895 under a Sierra or Nosler 168 gr JHPBT match bullet in Federal brass with Federal primers. When using Winchester or RP brass I used 41.5 gr
With RL 15 I used 42 gr with Fed brass. I use standard Lee dies & resizing brass from the DPMS is always easy. Easier than from 90% of any range pickup commercial
brass.
Accuracy was and is consistently under 1 moa with 10 shot groups.
The fed brass & 4895 load was chrono'ed at 2490 fps.
The LR 308 is one fine autoloading rifle. Accurate, reliable, powerful and just seeing it makes GFWs (Gun Fearing Wusses) wet their pants.

Roger

1stmarine
September 14, 2011, 11:19 PM
looking for faster powders it has nothing to do with the length of the barrel only. Only if you are going to shoot light bullets seek the faster powder. A lighter charge will help but if you have the standard bullets or the heavies you need to stick to medium rate. With 18" is what you get you gain accuracy and sacrifice speed. It should be an amazing 500 yards system with 150-168 grainers. Now don't go and try to shoot a mule at 600 yards.

35 Whelen
September 15, 2011, 01:12 AM
I use H4895 in my 18 1/2" Scout rifle, but Varget and Re15 are both great powders. I stuck with the 4895 'cause I have a large jug of it.
308's also benefit from ball powder such as WW748 and 760. I personally don't care for them because they're all double-base which generally means temperature sensitivity.
35W

codefour
September 15, 2011, 03:07 AM
I too use IMR 4895 in all my .308 loads. I do not own an AR-10 but is second on my list of new rifles.

I do however have a Springfield M1A Super Match in .308 that has a 20 inch barrel. I load 41.0 grains of I4895 over a 168 BTHP and consistently get sub MOA accuracy. I do not use small base dies but will eventually try them when I remember to order them. I have had not feeding issues with standard RCBS dies set to a full length resize.

redclay
September 15, 2011, 05:46 AM
I use Lee standard dies for the 308 and they are working fine. I use RCBS small base dies for the 223 simply because I salvage so much range brass in 223

MEHavey
September 15, 2011, 11:54 AM
looking for faster powders it has nothing to do with the length of the barrel only.
You did look at the data, didn't you?
It is very much both barrel length and bullet weight dependent.

With 18" is what you get you gain accuracy and sacrifice speed.
It should be an amazing 500 yards system with 150-168 grainers
I'm afraid I have no idea how a shorter barrel increases accuracy,
and extended ranges require optimal muzzle velocity -- which generally requires
matching 'a' faster powder to the chosen bullet weight for shorter the barrel length.

... if you want to keep your velocity up/avoid increased muzzle blast/flash

MtnCreek
September 15, 2011, 11:58 AM
A shorter barrel is more ridged than a longer barrel of the same contour. All things being equal, a shorter barrel could be more accurate until it reaches the point where reduced velocities start to affect accuracy.

Kevin Rohrer
September 15, 2011, 12:34 PM
I am using 4198 in my 20" Scout Rifle, using 110gr. V-Max bullets for coyotes. I picked this powder to reduce muzzle blast and it does the job.

Jim Watson
September 15, 2011, 12:42 PM
I tried hard to like AA 2520 because it meters so well. But it was not as accurate in my bolt action and Krieger barrelled AR as the extruded powders, so I shoot mostly Varget with some Re 15.

Ateam-3
September 15, 2011, 12:58 PM
I shoot a Remington 600 w/ an 18" barrel. I have tried IMR 3031 and Hod Bl-C2 and enjoyed good results. In 1995, I switched to Win 760 for this rifle. It has been the best powder for me.

1stmarine
September 15, 2011, 09:09 PM
You did look at the data, didn't you?
It is very much both barrel length and bullet weight dependent.
What data? Do not need to look at any data, it is the same with any load in the universe.
fast powders with long barrels and Heavy bullets with do not mix. you will hold that bottleneck pressure for too long to being safe. Actually less case capacity in this case plays to your advantage for fast light bullets so the purpose must be short-mid range. In the end everything balances out. A short solid bullet might be a good option as it sustains a tad higher BC but with the light weight, and grooves normally shows less pressure. Also the lack of S.D. is compensated by the fact that the solid bullets stay together through glass and other hard objects. Anyway I am drifting away from the subject. As I said you give up speed for extreme accuracy.

I'm afraid I have no idea how a shorter barrel increases accuracy,
and extended ranges require optimal muzzle velocity -- which generally requires
matching 'a' faster powder to the chosen bullet weight for shorter the barrel length.

... if you want to keep your velocity up/avoid increased muzzle blast/flash


All things being equal a shorter barrel is more accurate. The tone in the barrel is going to be a higher one and that translates into more accuracy nodes with any load.
Many swat/police rifles are in the 20" even 18" length as the average engagement distance is normally below 100 yards no heavy bullets (high BC) is needed. The flash / recoil is managed with brakes or suppressor that can be taken off. So these systems are normally very compact, light and extremely accurate. I any case a 18" or 20" 308 Win is an awesome 500 yards rifle with the right loads and training.

redclay
September 16, 2011, 05:13 PM
Guys, thanks for all the info, might be more than I can use at the present time. I have picked up some H 4895 and some 168grn Match Kings. I will load up some samples and see where they hit paper and go from there.

Thanks again

1stmarine
September 16, 2011, 09:59 PM
You should also buy one box of 155gr A-max. I heard they are very good with shorties. Also the V-maxes. I use them in all the calibers, they are not too expensive, great BCs and shoot like the house is on fire. SMKs are also awesome but that 155grainer is a nice choice for a shorty.

I found this article where this guy tested in a 16" SPR home made build system. I tried a 155gr AMAX load from HSM. Buy a box and If your system likes it all that you have to do is to find how to replicate that one.

http://www.snipercentral.com/boltdmr.phtml

4895 is a good choice and very versatile powder but it might be a tad slow so I would also try:

(From slower to faster)

- BLC-2.
- Winchester 748 .. burns very clean and amazingly cold. (no much heat).
- A 2230
- Benchmark
- H322

Follow the bullet manufacturer data. Verify with several reliable sources. Start low and work you loads up slowly so you can stay away from the red!!

Have fun and be safe.

ants
September 17, 2011, 07:02 PM
I have picked up some H 4895 and some 168grn Match Kings. I will load up some samples and see where they hit paper and go from there. You are almost perfectly right there.
Optimum perfect load for my 16" and 20" is IMR 4895 43.5 grains with 168 Match King
in brass weighing 180 grains (plus or minus 2 grains).
Adjust powder charge a tenth or two up, if your brass weighs less.
(Note: That is sorta my handload Federal Gold Medal Match equivalent, ymmv.)
Go ahead and shoot up that H4895, it is nearly identical.
Then buy IMR next time.

If you go up to the 175gr Match King, try the same powder charge OR go to R15.

A decent alternative to both powders is IMR4064. It's good.
But not as good as the other two.

ALWAYS go to your manuals and verify data.
Don't take my word for it on the loads listed above.
Check them against published data first.




My own dumb little personal point of view:
I don't argue about short-barrel-fast-powder or long-barrel-slow-powder.
In the AR10/LR308 platform, accuracy is found in consistency, cycling the action, and shootability.
All the velocity charts in the world mean nothing if you can't get those three things.
Velocity is highly meaningful in a bolt gun at 600 to 1000 yards.
Your 18" DPMS is probably not a 1000 yard gun. Just go for best accuracy, reliability and shootability.



Small Base sizing dies: Neither my Armalite AR10 nor my DPMS LR308 need them.
In fact, I don't even have to screw my dies (new Lee, old Herters) all the way down to the shellholder.

1stmarine
September 17, 2011, 08:05 PM
BE CAREFULL IMR4895 is different than Hodgdon 4895 so follow Hodgdon as ants pointed out. Alos check manufacturer bullet loading charts.
As I said, try the Amax 155 and some of the faster ones in 16". IMRs are good too.

Wireman134
September 17, 2011, 09:17 PM
As a general rule, barrels 18" and over get maximum burn of powder.

1stmarine
September 17, 2011, 10:13 PM
Not with the H4895 and varget powders. 20" is more likely that's why I suggested a faster powder with a lower drag bullet.

If you enjoyed reading about "powder for 18" .308 ?" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!