30" Std Palma contour chambered in 6x284 Velocity expectations

[Worker]

My new bbl will be 30" 8"twist I wonder what I can expect for velocity shooting 107 MK and 115 DTECs ?

 

[mike in co]

not enough info....
but with a berger 115vld and an oal of 3.1 and a bunch of h4350 software says about 3250fps
and 3250 with the 107......at 2.990.........
both have .24 neck seating not counting boat tail
nieether case is full but max pressure

 

[Charles E]

4350 isn't the right powder. Bill Shehane use to shoot one when he was winning a lot of 1,000 yard BR matches. In an effort to refine it, he & Dave Tooley started running the reamer in short, first .100 short, then .200 short. I had one of the .200 short chamberings. Also a 30" barrel. IIRC, I got 3,250 using H4831 with 106 Clinch Rivers. I could get 3,400 with Rel-22. With the full-length chamber, you can probably use Rel-25, esp with the 115s. Still, I suspect 4831 will give better accuracy.

Go look at the match report equipment lists in 1995, 1996 for Bill Shehane. He might have listed both which & how much powder -- it's on the form we all fill out.

Shoot 3-shot groups for testing. You don't get many rounds out of full 6/284 chambered barrel -- 500 or less for match grade accuracy.
Velocity starts falling off earlier. Oops!

For reference, the 6/284 held in .200 has exactly the same capacity as the 6mm Ackley.

 

[Worker]

It will be a full chamber,won't be shooting in any matches. More a long distance varmint/predator rifle. This is 2nd bbl 1st was a 26"Hart 10" twist shooting 70-90gr bullets. I'd rather shoot the heavies and utilize their high BCs.