240gr SMK with a 1:10 twist??

[edenfies]

Can you shoot a 240gr SMK out of a 30-378 weatherby Accumart V that has a 1:10 twist?? Will it stabilize the bullet? I'm also still looking for load data that anyone might have using H50BMG or Retumbo with this bullet and cartridge combo.

 

[jmden]

There's a few post out there on this, but, yes, at the speed generated by the 300 RUM and up, it'll stabilize out to some distance beyond 1000yrds and then at some point, from what I'm told, you can't hit the side of a barn. I'm shooting 104.5g US869 and am at or just above 3K fps with a 300 RUM with bullet seated right on the lands. Haven't tried H50BMG with that bullet, but I think Retumbo may be too fast. US 869 is not especially temp stable and the load given above is a cooler weather load. Reduce as appropriate for warm weather (45 deg or above). A 30-378 should move the bullet along nicely with US 869. Good luck.

 

[HoytemanPA]

Yes it will stabilize the bullet, I have tested to 1300. Start around 106 H50BMG and go up.

After testing with 200 Accubond, 210 Berger, 220mk, 240mk, H50BMG, Retumbo, US869 combos, my current 10 twist 29" Hart Barrel prefers the 220mk with 113gr H50BMG behind it.

When I used the Accumark barrel, 200gr Accubonds/106-107gr Retumbo worked the best with 220mk/115H50BMG a close second.

 

[Marine sniper]

Yes it will stabilize the bullet, I have tested to 1300. Start around 106 H50BMG and go up.

After testing with 200 Accubond, 210 Berger, 220mk, 240mk, H50BMG, Retumbo, US869 combos, my current 10 twist 29" Hart Barrel prefers the 220mk with 113gr H50BMG behind it.

When I used the Accumark barrel, 200gr Accubonds/106-107gr Retumbo worked the best with 220mk/115H50BMG a close second.

What kind of velocity are you seeing with the 240's in the 29" barrel?

 

[HoytemanPA]

MS,
3150 with 107.5 H50BMG, I went as far as 111gr which produced 3230, and ejector marks.

The 220's with 113gr go 3250, at 115gr 3290.

HPA

 

[115vld]

A friend of mine who is a sniper instructor out at Ft. Hood says they run the 240 gr SMK on some of there special forces 300 win mags and they are using a 9 twist. With the 10 he said that they are stable to about 1350+/- and could go in any direction after that. With the 9 twist they are good out to 1600+. Just what he said so take it for what its worth to you.

Chase