Need some advise from hand loaders for a 308 please

[grubbylabs]

Rifle DPMS GII Recon 16" barrel 1:10 twist
I have been in search of a good load for this rifle ever since I got it home.

I have primarily used Lake City brass.

Powders I have tried are IMR 4064, Varget and surplus H335.

Bullets I have tried. SMK 175 grains Hornady 168 grains 150 grain soft points and FMJ.

I used Varget with the 168 grain bullets. The 175 grain SMK's or 180 grain SST' are next with Varget. I have tried the 4064 and surplus H335 with the 175 grain SMK's. I tried the H335 again with some 150 grain Hornady soft points. And tonight I finished up with some 150!grain FMJ's over the 4064.

Nothing has given acceptable groups. The best I have managed is just over an inch @ 100 yards from a rest. All groups are at least 5 rounds. Which is a little discouraging since I can get clover leafs from a Marlin XS7 in 308 from a rest.

So I am thinking I need to try another powder and was thinking about one of the 4895's either IMR or H. But I am not sure. It seems like some have really good luck with RL -15 as well.

I am open to any advise and suggestions. Thanks.

 

[44 AMP]

I know it is nearly heresy to suggest this, but have you considered the fact that your AR .308 might not be a sub MOA shooter? internet claims to the contrary, not all of them are, even with the most carefully tailored ammo.

It wasn't all that long ago that any rifle, let alone a semi auto that shot just over an inch at 100 was considered a very good shooter.

In general the .308 like medium burn rate powders, and in a gas gun like yours, going to either end of the burn rate is usually not the best idea.

IMR 4895 nearer the slower end of the range, and quite good in some .308s (but each gun is an individual as to what gives it the best accuracy). I wouldn't go to any slower powder in an AR.

I've had good results with IMR 4064 & 4320 (in bolt guns) and usually run a ball equivalent load of WW 748 in my M1A.

Don't give up, but what you got right now isn't bad for a 16" barrel carbine AR that isn't a match rifle. You might wind up trying hundreds of bullet & powder combinations trying to shrink your groups 1/4". Or you might find the magic combination next week. No way to tell from here.

Good Luck!

 

[Howard31]

308 loads

I have shot a lot of 308 over the last 30 years . Likely in excess of 40k rounds. I have 2 bullets I use consistently , the 168 SMK and the M118 173 pulls. I basically used only IMR 4895 only for 30+ years but 3 years ago I tried Varget. I use Federal 210M primers and LC brass.
(1) 41.5 IMR 4895 either Bullet
(2) 43.3 Varget w/ either bullet
If these 2 loads don't shoot 1 MOA for you , you have a shooting problem or a bad rifle.
4064 is an excellent powder and I know many Hard Dog shooters that do use it. I shot the Garand across the course for years . For me I started with IMR 4895 , it worked for me and I stayed with it.

 

[grubbylabs]

44 AMP that is what I am beginning to believe. No its not a match rifle, but I wont give up on trying to find the one load that gives what I am looking for, that's half the fun of loading and shooting. It might take me several hundred attempts to find the right combo, but in the end it will be worth it.

But then again, I might just have to learn how to shoot.

 

[TATER]

I load for my father In Law.
147-150 surplus Ball, and Win-748 to Mag length.
He is using the same rifle and is getting right at .75"

 

[Unclenick]

Try a box of Federal Gold Medal Match ammo that uses the 168. It tends to shoot well in most any gun chambered for the .308. It would give your expectations a baseline to work from.

Also note that H335 is a little fast for heavy bullets in the .308. BL-C(2) is the civilian version of WC846 originally developed for ball ammo in the 7.62 NATO. Though, I have to say I don't think of it as an accuracy powder, particularly.

 

[Jimro]

If this doesn't shoot for you, it's your rifle.

Lake City Brass sorted for uniform weight with neck/shoulder annealed. LR marked brass is preferred.
Fed GMM205AR primer
41.7 gr of IMR4064
175 SMK

Load to mag length.

Jimro

 

[grubbylabs]

My gun did not like BLC-2. with a 150 grain bullet it was piercing primers at 46 grains. 45.5 looked just fine, but at 46 it was ugly. The Lyam book listed 49 grains as max. I loaded up 5 each at 1/2 grain increments till I got to 48 grains. But I quite shooting at 46 grains.

 

[chiefr]

I know it is nearly heresy to suggest this, but have you considered the fact that your AR .308 might not be a sub MOA shooter? internet claims to the contrary, not all of them are, even with the most carefully tailored ammo.

I have to agree with AMP. No heresy here, from all may range time I have seen very few sub MOA AR 15s.

 

[Dave P]

" It might take me several hundred attempts to find the right combo, but in the end it will be worth it."

Instead of shooting in the dark, and hoping for the right combination, try a more structured approach: Audette Ladder method. (or similar)

In bolt guns , i can develop a great load with just a handful of shots. Same with good AR's also.

 

[4runnerman]

Seems to work in all rifles

175SMK
42.3 gn RL-15
CCI-BR 2 Primers

168 SMK
43.2 RL-15
CCI-BR-2 Primers

As I say- Seems to be a great load in all 308's.

 

[jeager106]

I had a DPMS .308. P.O.S.
It would only shoot 125/130 grain bullets & shot them very well.
Groups inside 3/4 " without issue.
150, 165, & 180s would pattern like a s.g. at 100 into 4 to 5 inches no matter the load.
I sent it back to DPMS. They sent it back 6 weeks later saying "shoot only 125/130 grain bullets. This rifle will not shoot 150, 165, or 180 grain bullets for crap."
I sold the p.o.s.
Good luck.

 

[grubbylabs]

I am prepared to find out it is not a sub MOA rifle.

I am hoping it can be better, but I don't fully expect it. This is only my second gas gun. So I am by no means an expert loader for one. Let a lone an expert loader for any thing else. I was kinda hoping that some one or rather several someone's would pop up and say something to the effect of "well no duh dummy" those powders are not ideal for a gas gun, you need to try powder X and bullet Y."

 

[chiefr]

^^^^^^^^
My best 308 loads have always been with the 168s first, then the 175s. 748, has always been my favorite, but several years ago, I tried H Benchmark and this has been my go to powder for the 308 and 168s.

The last thing I would do before I got rid of or safe queened the rifle would to try different COLs first.

IMHO, I still agree with 44AMP. There are 15s that are not that accurate.
I will go as far as saying the same accuracy issue exists with some M1As.

 

[grubbylabs]

Its not going any where, it is still a fun gun to shoot.

 

[wachtelhund1]

IMR 4064 has always been "the" powder of choice for the .308 Win. Acceptable accuracy is different from person to person as to rifle to rifle. I live in Northern WI and my go to deer rifle is an old Winchester Model 100 carbine in .308; not known for being the most accurate rifle. I've glass bedded this carbine and it shoots consistent 1.5" groups with IMR 4064. I load 42.5 grs behind Speer 165 gr SPBT bullets. For a woods deer rifle this is great!

I have other guns (F class and varmint) which I would not consider such groups acceptable and would rebarrel them to get sub MOA groups.

Sometimes one just has to accept a rifles' accuracy!

 

[Unclenick]

Jimro,

That small rifle primer you listed will only fit the Lapua Palma brass, though that is good brass to try. For .308's with floating firing pins, I've been astonished by the consistency of the inexpensive Russian Tulammo KVB762 primers. As good or better than Federal 210M's in most loads, as far as velocity SD goes.


Grubbylabs,

If a test box of GMM .308's with 168 grain SMK's doesn't fly, take the suggestion to try some lighter bullets. They introduce smaller recoil moments to the barrel. If you were going to get good accuracy from your handloads of the heavier bullets, Varget or 4064 should have given it to you with the correct charge weight and seating depth. Another thing you can try is finding a catsneeze load using IMR Trail Boss. These won't likely function the gas system, but the low recoil doesn't disturb the barrel much, so you can get a better sense of how much recoil is responsible for the accuracy issues.

If you want help designing the seating depth experiment, read Berger's note on finding seating depths for their secant ogive VLD designs. Also read item 3.0, here, for encouragement.

I would not recommend the Audette ladder for such a short barrel and sight radius unless you have 300 yards to work with and can stay on paper with the gun at that range. Dan Newberry's OCW round robin approach works at 100 yards.

 

[Bart B.]

Don't forget, whatever accuracy variables the shooter has are added to those of the rifle and ammo.

Most people hanging onto a rifle that's shot resting atop something on a bench add about 1 MOA to whatever the rifle and ammo would do in a machine rest. There's a few that'll add a lot more.

"Most" people = any number over half of them. I'm in that group. Not ashamed to admit it. Us humans are the least repeatable thing on the firing line.

 

[Jimro]

Unclenick, you are correct, my bad for not double checking my post before clicking "submit reply." I'd blame copy and paste but I was so sleepy when I wrote that reply that I think I just fat fingered it.

The primer should be a GM210M. With the correct primer that is basically the recipe for Mk316 Mod0, which was designed to work in AR based SASS rifles (Mk11s, SR-25s) as well as M14 and Rem700 sniper rifles. I say basically because the Mk316 calls for Federal brass that I've never seen for sale as new unfired brass, but from the stuff I've handled, looks like sorted LC brass will substitute in just fine for reloads.

I appreciate the catch.

Jimro

 

[Unclenick]

And I think that mk 316 m.0 is supposed to be good in the M14, too. It surprises me only because of the primer sensitivity spec. I'd be curious to know if they've had any slamfire reports with it in the gas guns, but we may never know. Certainly the Federals have a slamfire reputation among match shooters, and board member Slamfire has personal bad experience in that regard.

My dad has a box of Federal .308 brass he bought new on Commercial Row at Camp Perry some years back. So they sold it separately on one time. The main problem seems to be that it is softer than most other cases, so its reloading life is only good with moderate load levels and not with full house loads.