IMR4320 in a 308

[badboyparamedic]

New to the forum(joined today), does anyone have any experiance using IMR4320 in the 308?

I am considering 24 grains of IMR4320 in a 308 with a 180 grain cast boolit.

[Larry Gibson]

4320 is a tudge slower than 4895 and should work fine with the 180 gr cast. Suggest a 1/2 - 3/4 gr dacron filler to improve ignition efficiency. Work up to 30 gr of 4320.

Larry Gibson

[badboyparamedic]

Thanks, that was kinda what I was thinking too. Forgot to mention the filler in my first post.

[badboyparamedic]

Got a chance to go out and shoot some of these loads today. good groups, were about 4 inches lower at 100 yards than the 180 grain remington factory loads, but good groups.

used 25 grains of IMR4320 with 1 grain of fiberfill, going to try to work up to 30 grains .5 grains at a time and see how the do.

using 180 grain boolits cast in a Lee mold, water dropped then gas checks added. running them through a .309 lee sizer, tumble lubed before and after sizing.

[madsenshooter]

It's not often one sees 4320 used with cast, though there's no reason not to. It's a gentler push upon ignition than the faster burning powders. Sounds like you're off to a good start, keep at it!

[badboyparamedic]

Only reason I have it is I stumbled onto 10 1lb cans for $8 a can. It seems that it can be used with 308, 223 and a few other things in reload. I prefer H335 but for $8 a pound I will learn to use it.

[madsenshooter]

So would I!

[rexherring]

Years ago my father had a bunch of surplus 4320 and we used it in everything like the .303, .30-06, .30-30, 257 Roberts and my old 7.62X54 Russian. It always went bang.

[Lefty SRH]

What rifle did you develop this load for? Any idea on velocity? What was the group size, center to center? Barrel length?

[Larry Gibson]

My guess is you will find real happiness at 28 - 29 gr......problem is you will cry when that 10 lbs are gone and you want/have to get more........at todays or tomorrows prices........

Larry Gibson

[badboyparamedic]

Savage 112 with a 24 inch heavy barrel, only loaded 10 rounds, 2 groups of 5 each average group size was 1.57 per group center to center. Don't have any idea on velocity, first attempt at casting and loading, just wanted to make sure they were going to feed and shoot ok.

seated bullets to crimp groove, which made COL about .120 shorter than Remington factory loads I usually use but boolit depth in case was same as factory loads.

[Lefty SRH]

Thats a good group to start out with. What alloy blend and lube?

[badboyparamedic]

COWW and 45/45/10 tumble lube

[nanuk]

1.6" groups
was that at 100yds?

[fishnbob]

Only reason I have it is I stumbled onto 10 1lb cans for $8 a can. It seems that it can be used with 308, 223 and a few other things in reload. I prefer H335 but for $8 a pound I will learn to use it.

I would like to stumble on a find like that. I've been using 4320 in my 22-250's since 1967. Great groups, not too hot and good velocity. 36.0 grains of it with a 52 or 53 grain Hornady is just under 3700 fps.

[badboyparamedic]

Yes it was at 100 yards, the rifle will consistently shoot .5 inch groups using 150 grain jacket bullets loaded with H335 from a bipod.