Home Forums Hunting & Shooting Ask The Gunwriters 308 Powders

Yeah, Trail Boss works great in the .308.

Another fine .308 powder that Bill Wilson (of Wilson Combat) turned me onto is Alliant AR-Comp. Unfortunately, it's just about completely disappeared. Tried to find some recently with an Internet search, an no-go.

Another fine .309 powder, however, IS widely available on the Internet, and right now is one sale in many places--IMR 4166, one of the Enduron powders. Back when the Endurons appeared in 2015, one of the reasons was how much difficulty Hodgdon was having in gettting the Extreme Powders (including H4350 and Varget) from the Australian plant where they're made.

As a result, the original Endurons tended to be similar in burn-rate to popular Extremes, including 4451 being similar to H4350 and 4166 being similar to Varget. I was assigned to do an article on IMR 4166 that year for the Hodgdon Annual Manual, and they sent me an 8-pound jug to playe with. I ended up trying it in around 8 cartridges, including the .308, where it works just about like Varget--if Varget included a decoppering agent.

I still had a good supply of Varget on hand back then--and still have quite a bit left, along with most of that jug of 4166. Which is why I haven't been desperately searching for Varget. If I was, I'd consider ordering another jug of IMR 4166.

Not to change this off of the 308, but have you tried 4166 in the 9.3x62 John?

Not yet. Haven't had any need to, but am sure it would work fine.

No worries, figured since Varget is a bit tough to grab 4166 may be a good alternative if 15 doesn’t work out for me.

15 goes through my powder measures smoother than 4166.

And 4166 has proven more temp-resistant than Reloder 15 in my tests. Depends on what you want!

That never hurts a thing in my book. I tend to like 15, so if it’s a bit better I’m okay with that!

John, have you used 4166 in .223? Hodgdon's data shows somewhat less velocity than Varget in that cartridge.

I recently came into my first 308 in a number of years. Being in Kodiak, I don't have access to a huge number of powders, I brought some Varget with me. I tried Varget and 8208. 43.5 gains is a great load for 178 ELD-X, 41.7 works great with 200 grain Bergers

Yes, I did try one load for the Hodgdon manual article, which involved comparing results from their test barrel and my rifles, working up to maximum loads. It was accurate but on the slow side, partly because the rifle I used had a 22" barrel, and the test barrel was 24". But in my rifle it was a little slower than expected--and 4166 also didn't flow through a .223 neck very well, bridging fairly often.

It worked fine in the .243 Win., .257 Roberts, .308 Win., .303 British and .45-70, with fine accuracy and velocities very close to Hodgdon's data.

Going through a drawer with some old back issues that I thought were worth saving, I picked out the August '94 issue of Shooting Times where Rick Jamison did the most exhaustive .308 test that I've seen to date. "The .308 in Depth!" "Searching For The All-Around Short-Action Load" Rick did a 1,000 round test and determined that the 165-168 grain bullet range was the ideal bullet weight for a .308. Eight pages into the article is the sub-title "Revealing the Ultimate .308 Loading".

Powders:
Highest velocity: RL 15
Lowest charge weight to get pressure: N-202
Lowest extreme spread on pressure: VV N-550
Lowest standard deviation on pressure: VV N-550
Lowest extreme spread on velocity: RL 15
Lowest standard deviation on velocity: AA 2520
Smallest three shot group: N-202
Smallest five shot group: RL 15
Smallest 10 shot group: W748

In the article itself he writes that RL 15, W748 and VV N-550 gave the highest velocity and then writes that the powders that produced the most uniform results in terms of velocity extreme spread and standard deviation would be the AA 2520, RL 15 and H4895.

I haven't reloaded in years, so I don't know if these powders are still available or that others haven't proven better. For what it's worth.

Windfall,

Many things have changed since then--including Reloder 15 and VV N-550.

Back then RL-15 was VERY temperature-sensitive. That was improved around 2000.

VV-N550 is now a temp-resistant powder which includes a decoppering agent.

Back when I started gunsmithing, it was widely accepted, if you built a 308 which didn't shoot with 4895 and 168's, you might as well tear it apart and try again. 4895 is still my favorite powder for 308 accuracy loads. I have a jug of 4166 to try and just have not gotten around to it. GD

Thank you, sir. I will reserve it for .308.