Super heavy weight 308 Winchester loads.

[DeanWinchester]

I have a mold that drops about 240g @ .312 and I size them back t .311 for a little experimenting with 308 Winchester.
Thankfully milsurp rifles have very generous throats otherwise, this thing would never fit in there. I'm also limited to two or three rounds in the ten round magazine or they bind from them being too long.

Anyway, I've fired em over 12.0g of Trail Boss with moderate accuracy. They will not stabilize and I KNOW this. They aren't key holing real bad but at 35 yards you can see evidence of it from the holes they make. I'm hoping to speed them up just a little and maybe help some. I don't expect super tight groups and they will likely go all over the place after a hundred yards. I am after a fun load to bust rocks, dirt clods and clay targets inside 50-75 yards.

Anyone have a good guess what charge of Unique would put me around 1600-1700 fps? I'm thinking of stuffing some over the standard 10.0g of Unique and letting them fly. Don't want to go much faster, they are a plain base boolit.


Man! I really need to get me a new chronograph.

[truckjohn]

How about the go-to standard load of 16g of 2400 powder? Work up from there...

With the 240g slug - you may not have enough twist to stabilize it unless you are at 1:10 twist or maybe faster.... The 200g slug like the 311299 should do fine with 1:10 twist.... but you may need to look at 180g and lower with 1:12 twist common in 308's...

Thanks

[DeanWinchester]

I don't have any 1600. I may grab some next time I'm at my supplier.

I have boolits that are more appropriate for serious work. This rifle is a 1/12 twist and I know they'll never stabilize. I'm just goofing off. Not like we need a real explanation for some of the things we do.

[truckjohn]

Yeah.. Should read 2400 powder... I edited it, but apparently not before you replied....

The "Go-to" 1600-1700 fps load starts with 16g of 2400 powder under a 200g GC slug. It works well with most any 30-caliber cartridge that falls between a 30-30 and a 30-06 case capacity wise....

Thanks

[Larry Gibson]

I suggest you try a much slower burning powder and boost the velocity over 2000 fps, might surprise you. Try powders (hard to say what you have or can find these days) from any of the 4350s up through RL22.

Larry Gibson

[DeanWinchester]

I suggest you try a much slower burning powder and boost the velocity over 2000 fps, might surprise you. Try powders (hard to say what you have or can find these days) from any of the 4350s up through RL22.

Larry Gibson

I got some H4350. Got a suggested starting point?

[Larry Gibson]

I got some H4350. Got a suggested starting point?

Start at 32 gr with the dacron filler. Work up in 1/2 gr increments. When load density hits 80% drop the dacron filler and consider you may be very close to max with that weight bullet. If you proceed above that do so carefully watching for excessive psi signs. If you've a chronograph approach 2000 fps with caution and anything over that. You're really in unchartered territory there so be careful.

Larry Gibson