Advice on .308 AR-10 powder for new re loader

[Rod47]

Thinking back about 20 or so years....when the US Palma Team competed in Australia, their issue 7.62 ammo used a ADI powder which Hodgdon soon marketed as Varget. Also thinking LR118 was originally loaded with RE 15 at Lake City. Both good choices

 

[2ndtimer]

These days, you sort of have to take what you can get, as many powders are difficult (or impossible) to find in stock. I have used several in my non tack driver PSA PA10, including IMR-4064, Ramshot TAC, BL-C2, IMR-8208XBR, Accurate 2015, Winchester 748, and Reloder 10x. Since I mostly shoot paper and steel, I have gone to the Speer 125 gr TNT bullet for my AR. That bullet seems as accurate as anything else and is quite affordable when available in the 500 bulk pack, usually around $75 on sale. I got a good deal on a 5 lb keg of Reloder 10x, and run 40.0 gr with the TNT. It runs reliably and mitigates some of the recoil, too.

Good luck finding H-4895, IMR-8208XBR, AR COMP, or Varget. I have had the best luck with TAC, IMR-4064 and Reloder 10x of the more available powders. I have a pound of Accurate 2460 to try some day, and if I win the lottery, there is always the Vihtavuori powders from Finland to try.
Let us know how it works out for you.

 

[James Fonteneaux]

I've used both Winchester 748 and IMR 4064. With 150 grain bullets out of my 16" barrel, I got better groups with 4064. Win 748 is MUCH easier to meter though. I still have some more tinkering to try and @2ndtimer's idea of using the Speer 125 grain TNT is intriguing. I've been using those for a 300 Blackout carbine with good results. Maybe time to try them in 308 or even 30.06.

 

[tcoz]

That is a very good price. Thank you, I have it in my cart right now for back order, which is fine I can wait. @Loco I will research the H4895

What are your thought on the IMR4064...its plastered all over the internet.

Also looking to produce reloads with 150g bullet in the 2800fps muzzle, I want enough gas to cycle my bolt effectively. Had some under powered stuff that sucked.

IMR4064 is my old standby 308 powder. At one time or other I’ve used it in every .308 that I have as well as my M1 Garand. Currently I use it in my Savage SA in an MDT ESS chassis and it’ll shoot sub MOA all day. The only drawbacks are that it’s a little more expensive and also might not meter well in your powder measure. Burn rate is similar to Match Rifle.

 

[berettaprofessor]

I've used Benchmark and Varget to good affect. Varget is my more slightly precise load in the AR-10. Faster, also, than the Benchmark.

 

[Bfh_auto]

One thing to remember is. If your trying to go fast in an ar platform. You will shred brass. The powders that give you the highest velocity usually work best with an adjustable gas block.

 

[Reloadron]

Loading for my AR 10 or even my M1A my powders of choice are IMR 4895, Hodgdon H4895 and Accurate Arms AA 2495. While there is no shortage of other powders I seem to gravitate to those three, especially where a gas operated rifle is concerned. Bolt guns I use those and a few others which are just a little slower. I should point out also on top of those powders I like either the Sierra 168 grain Match King (#2200) or Speer Gold Match 168 Grain (#2040) bullets. Now if you just want consistent shootable ammunition Hornady 150 Grain ((#3037) or similar Sierra or Speer shoots fine.

Try several powders and loads and see what works best for you because what works great for the shooter beside you may shoot lousy in your rifle.

Ron

 

[JussRight]

I appreciate all of your helpful comments. I think I have narrowed it down to IMR4895. Google told me that 155 cartridges in 1lbs of powder. Very cool that google got the information from The High Road...it quoted a post from here dated Mar. 17th, 2005. The members name is Mark whiz.

So this forum is the quintessential internet website of reloading knowledge. Hahahahhahahhaha...Awesome!

 

[Reloadron]

Figure things this way. When we measure powder for loading we use gr (Grains) as the unit of measure. The powder here in the US is sold in Lbs (Pounds) as the unit of measure. Just as a reference there are 7,000 grains in 1.0 Lb. A typical .308 Winchester load under a 150 grain FMJ (Full Metal Jacket) bullet will be between 38 and 44 grains of IMR 4895 powder. Taking a maximum load and adding a grain we can figure 7000 / 45 = 155 rounds so a 1.0 Lb can of IMR 4895 should yield about 155 loaded rounds. It will always be 7,000 divided by your load data with both expressed in grains to get how many rounds you can load.

Ron

 

[JussRight]

Figure things this way. When we measure powder for loading we use gr (Grains) as the unit of measure. The powder here in the US is sold in Lbs (Pounds) as the unit of measure. Just as a reference there are 7,000 grains in 1.0 Lb. A typical .308 Winchester load under a 150 grain FMJ (Full Metal Jacket) bullet will be between 38 and 44 grains of IMR 4895 powder. Taking a maximum load and adding a grain we can figure 7000 / 45 = 155 rounds so a 1.0 Lb can of IMR 4895 should yield about 155 loaded rounds. It will always be 7,000 divided by your load data with both expressed in grains to get how many rounds you can load.

Ron

Thank you sir! Once again super helpful and accurate information. This site is just the best on the net.

 

[ScubaSteve99]

Walked into my local Walmart here in Vancouver, WA and checked their always depleted ammo shelf and saw some reloading dies. I started looking around and saw Large Magnum and Small Magnum primers and then there was 10 100ct. boxes of Winchester Large Rifle primers, so I snagged them. I would have never thought to look at Walmart for reloading supplies. I have my Dillon .308 die set and primers, now I need some brass and powder. Any advice on .308 AR-10 powder for new re loader?

I'm a big fan of IMR 4064 for ally full power cartridges. I haven't loaded 308 with it in a while but I do load a good bit of 7.65x53 and that's right in the same neighborhood as 308.

 

[JussRight]

Full power charges, sounds appealing. I do have a goal in mind. To push a 150 or 155gn at 2800fps out of a 16 inch AR10

 

[Metal God]

2800fps from a 16” barrel is not likely , I think Varget & CFE 223 might get you with in 50fps but those have a slower burn rate then the 4895’s which will put you way over gassed . An Adjustable gas block could help with that but those slower powders really are better suited for the heavier bullets

With the powders being discussed. Id think 2650 to 2700 may be more realistic from a 16” barrel

I’m getting 2760fps using over max load of H-335 from my 18” AR-10 . Which I now plan to reduce that charge by .5gr to put me right around max pressure resulting in a likely 30fps reduction or 2730fps

 

[JussRight]

2800fps from a 16” barrel is not likely , I think Varget & CFE 223 might get you with in 50fps but those have a slower burn rate then the 4895’s which will put you way over gassed . An Adjustable gas block could help with that but those slower powders really are better suited for the heavier bullets

With the powders being discussed. Id think 2650 to 2700 may be more realistic from a 16” barrel

I’m getting 2760fps using over max load of H-335 from my 18” AR-10 . Which I now plan to reduce that charge by .5gr to put me right around max pressure resulting in a likely 30fps reduction or 2730fps

2650 -2700fps would be good enough. I do understand that my barrel length provides a limit. I can settle for that.


Here is a cut & paste of IMR's loading data for .308

 

[JussRight]

woops!

 

[Metal God]

Actually you are likely going to get that whole diagram removed because it’s copyrighted plus you can edit your post and insert that quote if you want just click on the edit button on the bottom

 

[JussRight]

Thanks bro...deleted

 

[Reloadron]

Full power charges, sounds appealing. I do have a goal in mind. To push a 150 or 155gn at 2800fps out of a 16 inch AR10

You may want to keep something in mind. Your maximum load for a gas gun like an AR 10, M1A or .308 chambered M1 Garand will not be the same maximum load you might run in a longer barreled bolt action rifle. While the load data you posted 45.5 grains of IMR 4895 may be fine and well in a bolt gun and with enough barrel may get you up to or above 2800 FPS the same may not be true of a shorter barreled gas operated rifle like an AR 10 and you may reach a point where you are beating your rifle up. Also, there is no gain in pushing a load when frequently the best accuracy is achieved before a maximum load. Choose a powder and bullet combination and work up. That is what I would suggest anyway. You will also find and likely conclude that published load data is a guideline and min and max loads vary book to book.

Ron

 

[JussRight]

I will take your advice to heart Reloadron. I will take it safely and slow. We have to be mindful that just a few short inches away from our face is a enclosed chamber that reaches up to 62,000 CUP pressures when shooting .308 cartridges.

 

[JussRight]

One thing to remember is. If your trying to go fast in an ar platform. You will shred brass. The powders that give you the highest velocity usually work best with an adjustable gas block.

Interesting, I have noticed the necks of my ejected brass are marred up. More than my AR15 brass. But I do have the KAK double extractor bolt in my BCG, I was having extraction issues. Now I don't. I inspected the single extractor after I replaced it and it looks good and the extractor is still ridged and stiff just like new?

 

[Charlie98]

EDIT: I didn't realize I had already commented on this... and said basically the same thing.

Just FYI, I have some bit of experience reloading .308 for a 16" barrel, my Socom16 M1a. When I first gathered data for loading, I settled on IMR4895... I was already using it in the M1 Garand, where it did admirably, and it was at the top of the 'classic M1a' powder list by many people. Except. That 16" barrel really takes a cut.

General 150grn M80 ball surplus ammos gets me in the ~2600fps range across the board.

My reloads, 43grn IMR4895 and a Winchester 150grn FMJ, launched at 2475fps, 43.5grn 2500fps. While the loads were accurate enough, I wanted a bit more velocity, but I was not prepared to take IMR4895 any higher... not in a gas gun, and not in my M1a.

I have decided to switch my primary .308 powder to IMR3031 for the short Socom16 barrel, and to IMR4064 for my Savage bolt gun (.308) and Garand... and leave IMR4895 behind.

 

[Reloadron]

Interesting, I have noticed the necks of my ejected brass are marred up. More than my AR15 brass. But I do have the KAK double extractor bolt in my BCG, I was having extraction issues. Now I don't. I inspected the single extractor after I replaced it and it looks good and the extractor is still ridged and stiff just like new?

If you watch a few slow motion videos of rifles like the AR 10 ejection process you will likely see why things like dinged case necks and case mouths are not all that unusual. Here is one such example. Shown in slow motion towards the end of the video. My own observation is for the most part on my AR 10 which was originally an 18" barrel and now a 26" match barrel is I get good ejection right about 4 O' Clock but with some loads I get the dinged case mouths. The rifle is about a 25 year old Armalite before everyone was making them. Anyway, gas guns like the M1A, M1 Garand and AR 10 have a pretty violent ejection process, note how the case mouths in the video slam back on the action. Different powders, different pressure curves, different ejection is how it generally plays out.

Ron

 

[JussRight]

I could not find any IMR or Hogdon 4895 anywhere. The powder that I did finally find was Vithvuori N550. The specs look great and claims it is specifically designed for 30.06 & .308. I have just now as of Monday worked out all the bugs in my 16" AR10 (heavy hammer spring, small diameter toolcraft firing pin, polished bullet ramps) I will be happy with 2650fps out of my 16" barrel.

 

[JussRight]

So my only concern with this powder is that it is stick powder and medium burn rate. Will I be pushing unburnt powder out of the end of my 16" barrel? I picture the base of my cartridge and the end of my barrel as the entire pressure building charge. Seems to me that 16" is a bit too short to benefit from the full extent of the full powder charge?

I have included a cut from Vithavouri for my 155gn boat tail ELD

 

[Reloadron]

I used and still use VihtaVuori powders for 308 Winchester and other cartridges. I always liked it and it worked fine for me. That includes loading for my M1A and AR10. During the early 90s VihtaVuori was the darling powder of the bench rest community.

Back to your AR10. I would not worry about unburnt powder. Just see how it goes and I never had an issue but my AR10 is a 24 inch barrel.

Ron