Which powder for 20" barrel

[Hunt]

I just had LRI build me a new 20" .308 stick and have been shooting 178 AMAX with Win. brass. The barrel is 20" 4-groove Krieger barrel with the Win. Sniper reamer. In load testing, I've found an accurate load with 43.1 gr IMR4064 but the load is only averaging 2435 fps. I'd like to get at least 2550-2600 fps with a 178 AMAX. Which powder will get me there b/t Varget, RL-15 or IMR4064 without getting into over-pressure?

 

[BapZander]

which powder is giving you 2435?

I'm loading 43.6 Varget, Win brass, 178 amax and getting 2560. I went up to 45gr but it was just starting to show pressure at that node.

~44 gr Varget should get you in the range you're looking for.

 

[Huckleberry75]

I got your desired results from 43.9-44gns of Varget with 178 amax

 

[Deadshot2]

A powder I've used in a 20" bbl .308 and managed to get good speed and accuracy is CFE223. 44-45 gr would be the charge weight range I'd work in. CFE223 works best for me when the load density is close to max. You'll find the powder to be a little "sooty" but it cleans up easily and copper buildup is almost non existent.

Powder may be more temperature sensitive but I haven't experienced that yet. Shot it in temps from the 20's to the 90's and results were pretty much even. Maybe if colder or hotter but not where I live and shoot. What I do like is that I can get a max charge in the case, under a 178 A-Max without having to compress it like with Varget or IMR-4064. The powder is comprised of multiple granule sizes, meters like water in all my powder dispensers, and settles in the case without having to vibrate or use a drop tube.

Works great for .223, both Bolt Action and Gas Op rifles. Like it well enough I purchased 32# of the stuff before the world lost it's mine and started hoarding powder.

 

[Hunt]

Edited above. I'm using 43.1 gr IMR 4064 with an OAL of 2.810. This is giving me an avg of 2435 fps. I want to clarify that I'm only talking 20" barrel, nothing longer.

 

[mzvarner]

i am using 43.5gr 4064 in a factory rem 700 20" barrel and averaging 2610 SD 16. my 43.8gr varget load gets the same average but a SD of 8.

 

[alpha6164]

I hate to even say this cause it's gonna make the powder even more difficult to find but you really can't beat CFE223 when it comes to velocity. I have achieved 2550 with 175g out of a 14.5" POF so I know with 20" it is a cake walk. I got 2833 ft/sec out of my 24" GAP 308 with 175g and still 1/2 MOA

 

[DGD6MM]

From what I've read here and elsewhere CFE is giving good speed. I bought 8# back in June, it is still unopened. I've got a .308 barrel waiting to be screwed on and shot. This will be time for some testing.

 

[datguy]

I have a 20" barrel in my FN SPR A1a. This is from a few hours ago at the range..

45.5gr Varget, Federal 210M, 168gr SMK, new Lapua brass. Two sets of 5, second one with .001 more neck tension. Federal GMM 168SMK clocked at 2554fps average in this rifle today.

 

[gigamortis]

I shoot 178 AMAX out of my factory barrel 20" Savage 10-FP. Lapua brass, 43.8gr 4064, at 2.850" gives me 2590fps. .020" jump to the lands.

 

[Danco411]

Sure if you can find Varget. It's like the White Rhino. I've used and Chronoed them all. While Varget is a great powder for the .308 and very stable it's unavailability makes it less than useless. The powder with the best velocity is Alliants Power Pro 2000MR followed by CFE it's close Hodgdon brother. Accurate as hell too. 47 Grains was getting me 2820 out of my 26" barrel. Others that you can work up good consistent loads with and FIND are 4046, XBR8208 and AR Comp.

 

[Doc68]

I'm pushing 2644 with 44.5 gr imr 4064 and 178 AMAX

 

[wwrhodes91]

2580 with 42.8 gr of 8208 XBR. Lapua brass

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