.308WIN handload powder suggestions .....

J

jimbob86

Moderator
.... for an AR-10, 18" barrel .... midlength gas system, rifle buffer ....

Looking to load 125-130 and 150 gr loads .... at what point on the burn rate chart do powders get to be too slow for this gas system? Obviously stuff like the 4350's is too slow ..... RL-15? CFE 223? IMR-4064? 3031?

I have some H335 and H322 ..... fairly sure those would be good candidates for the lighter bullets ....

Anybody have experience with this? I've reloaded for years, but until now, most of my rifle reloading has been for bolt guns.
 
I'm not shooting semi , bolt action 20" brl. I've been using IMR 4064 for years RL-15 also very good. Shooting a 168 gr. Sierra MK twist 1-11.27 zero 200 yards.
 
I'm not shooting semi
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Thanks for the response, cw, but the semi-thing (specifically, the mid-length gas system) is the unfamiliar part for me ..... like I said, I've handloaded for bolt guns a long while now .... I burn more IMR4064 than any other powder .... just think it might be too slow for this rig ....
 
With that size barrel, take a look at IMR3031, or even your H322 or H335. I would not use IMR4064, particularly with those light of bullets.

I have a M1a with a 16" barrel, originally I started with IMR4895, which worked OK, but once I switched to IMR3031, things started to pick up. If you were going to 165+ bullets, I would probably consider IMR4064, as an experiment.
 
"at what point on the burn rate chart do powders get to be too slow for this gas system?"

Just because the M-1/M-14 has limitations on the powder burn rate does NOT mean any other rifles have the same or similar or any limitation at all...

The AR "TYPE" rifles do not have these limitations.

Problem with the ARs is, past a certain point you simply can't put enough powder in the case to reach the velocities you want.

T.
 
335 and 322 work but you might like 4064 or 4895. I've settled on 4064 for all of my .308 loads as well as my 30-06 Garand loads. I shoot 155-175 bullets in both. I have a C308 18" and a DPMS heavy 20".
 
While I have never found my AR 10 to be as powder/pressure sensitive as my M1 or M1A guns I have gotten my best results using powders like IMR 4064, IMR 4895 and AA 2495 and tried to stay with powder burn rates above IMR 4064. Short of Berger Bullets my best results have come using the old Sierra classics like the 150 grain HPBT Match #2190, 168 grain HPBT Match #2200 ans the 180 Grain HPBT Match #2220. Additionally for general shooting the Sierra 150 Grain FMJ bullets. Powders like Varget and RL 15 have also given me decent results but the first ones I mentioned have always delivered the best results in my own AR 10.

Ron
 
It make perfect sense to me using a.faster burning powder in a shorter barrel . How would you know if all the powder is burned in a shorter barrel ? Is there a formula . I went through something like this , different subject though with barrel being to hot . Then I read an article on thermal strip to attach to your barrel , I have one on mine now. How would pick a burn rate to length of barrel.
 
cw308 said:
How would you know if all the powder is burned in a shorter barrel ?
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I experimented with 4198 way back when I was very new to handloading for the AR's. I was trying 4198 and 55 fmjbt's. I had consistent cycling problems. What was happening is I was getting "short stroking" of the bolt which was causing failure to feeds. 4198 burn rate was too fast. My go to powder for gas gun 55 gr plinking ammo is W748.

4895 is pretty much the 7.62 gasser standard powder. My M1, and M1A both function flawlessly with 150-168 gr bullets and 4895. AR DI type systems are even better as they offer more tolerance to varied burn speed powders.
 
Lotsa love here for IMR3031 ..... I do have a pound of it I was going to try in 7.62x54r, but IMR4064 did so well that I never bothered to work up a load ....

.... any quirks with 3031?

I hear it "does not meter well" but I would not know why it would be any worse than any other extruded powder .... I've burned many pounds of 4064 , most of it metered ..... never had any issues.

I read a few reviews, and several reviewers made mention of "almost as good as Varget, but cheaper" ....

Thoughts?
 
Real AR-10's used 7.62NATO. The issue with your's is the short barrel. You're not going to get rifle velocities out of a carbine by changing powders. You're going to have a big muzzle flash too.
"...what point on the burn rate chart..." Don't be over thinking the whole thing.
"...has been for bolt guns..." The only real difference is that you cannot neck size. Everything else is pretty much the same except for velocities.
 
Real AR-10's used 7.62NATO. The issue with your's is the short barrel. You're not going to get rifle velocities out of a carbine by changing powders. You're going to have a big muzzle flash too.
"...what point on the burn rate chart..." Don't be over thinking the whole thing.
"...has been for bolt guns..." The only real difference is that you cannot neck size. Everything else is pretty much the same except for velocities.
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I've loaded for shorter barrels (16") before ..... and the flash/blast issue was solved with quicker powders .....
 
You're not going to get rifle velocities out of a carbine by changing powders.
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No, but you will get potentially more velocity (EDIT: using the proper powder,) and possibly less deviation.

Very early on I tried IMR4064 in my Socom16, I could not get equivalent velocities vs IMR4895 with the same bullet, without redlining the load. Switching to IMR3031 fixed all of that... at least in my 16" barrel. YMMV. Not saying IMR3031 is the end-all, but it's a better place to start than IMR4064.
 
Jimbob86,

Something to understand about rifle powders is that they burn faster as pressure increases. This is one reason burn rate charts, no two of which seem to agree entirely, are called "relative" burn rate. They are actually tested by the makers under one set of lab conditions and how quickly one burns up in those conditions is compared to how quickly another burns up under those same conditions. If you change the pressure (and different cartridges do run at different pressures) you can atually change the burn rate order.

An example described by Dave Milosovich in the 1995 Precision Shooting Reloading Guide compared 4895 and 4064 in the .308 with a 180 grain bullet. Loaded to 2400 fps, the charge weight was the same for both. Loaded below that velocity, it took more 4895 and less 4064, as if the 4064 were the faster powder. Loaded above that velocity, it took more 4064 than 4895, making the 4064 appear to be slower than 4895. What was actually happening was just that 4064's burn rate doesn't change as much with increased pressure as 4895's does. This stuff can get confusing.

In general, you'll find your light bullets don't present enough inertia for a slow powder to build pressure against very well, so you get incomplete burning and the pressure curve is a little flatter with a slow powder, making your gas port pressure higher and the poor burning efficiency making gas with more particulate matter. Plus, in order to get enough of the slow powder burning to drive the bullet fast enough, you have to use more of it, meaning it costs you more to load each round.

The suggestion to try 3031 with the 125 grain bullets is sensible in terms of burn rate selection for that bullet weight and it has the highest listed velocity for the 125. It will save you money with lower charge weights. It will also run the 150's quite well.
 
Thanks, Unclenick.

I do Understand all of that ....just looking for folks that had done all this before ....

.... of particular interest to me would be experience with the shorter gas system I have in my rifle ..... some have opined elsewhere that the carbine length gas systems are junk in longer barrelled gun .... IDK, as I have no experience with loading for gas guns ..... I am aware from reading that Garands and M1a's op rods can be damaged with powders too slow for them .... and while this DI rifle has no op rod .... too slow a powder would still beat the gun, no? Or is there no down side to more port pressure than necessary for a given velocity attained, other than taking more to get there and leaving the gun dirtier (a concern with DI guns that poop where they eat!)?
 
If you look at military ammunition specifications for .30-06 and 7.62 NATO, they have a peak pressure limit, a gas port ±pressure window, and a ±velocity window, all of which have to be met by an ammo lot. 5.56 NATO is the same, except the gas port pressure only has a minimum value and no maximum is given. Nonetheless, you find aftermarket buffer springs of different strengths so you can keep from beating the gun up by sending the bolt back too hard.

Probably the easiest indicator is to shoot some commercial ammo and see where the cases go, and then see where your handloads put them.
 
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