Highest B&C bullet for a 12 twist 30cal.

distantfoe · #1 10-06-2005, 10:40 PM

I'm having a 300 jarrett built. My initial thoughts were to shoot 165gr Nosler BTs so I ordered a 12 twist barrel, big mistake. So I'm stuck with a new 12 twist barrel and would like to push the range envelope. Any thoughts on weight limitations for this twist? The rifle should push the 165gr at around 3500fps so should be able to push heavier bullet to relatively high velocities as well.

Thanks in advance

sewwhat89 · #2 10-07-2005, 12:09 AM

Berger lists 1/12 all the way up to their 190 gr VLD.

älg · #3 10-07-2005, 05:47 AM

rather than weight you should be looking at bullet length when talking about twist. there are some formulas around that may give you an idea of how big/long bullets will your 12 twist accept at a specific velocity.

DougH9 · #4 10-07-2005, 01:47 PM

I am in the same boat as you (except mine will be a 30-338). I picked 12 because I had good luck shooting 190's in a 308 12 twist at 1K. I am planning to use 180 BT's exclusivly (this is a deer rifle). Once underway, I wished I had picked an 11 twist, mainly because I might be forced into unleaded bullets in the future (endangered birds around here). I did a lot or reasearch, including asking here (very helpful), and my fears have been put to ease. My current take is that a 12 twist is probebly ideal for a 180 grain BT (or similar) bullet, fired out of a magnum. Just for kicks, I tried 200 SMK's in my 308 12 twist, and shot the smallest 100 yd groups it has ever done.

Warren Barrett · #5 10-07-2005, 05:19 PM

1-12 twist is used somewhat in the 1000yd br crowd up to 200- 210 vlds.

Michael Eichele · #6 10-07-2005, 05:41 PM

I shoot 200 grain accubonds out of my 12 twist 300 RUM and they stabilize just fine. BC of about .590 Probably not the highest but high enough.

Try the 178 AMAX. I get a SUPER HIGH bc with that one. I dont care what the published bc is. At 3100 FPS and a 300 yard zero that bullet fired from my rifle drops 37.75" at 600 yards. That is real world testing not a computer telling me this. My 200 grain accubonds at 3150 dont hold a candle to that! If you were to use the published bc in a computer program, the velocity has to be around 3465 for it to equal 37.7" at 600 yards. I am working on a load that should reach 3450. I wonder how little the drop at 600 yards would be then??

distantfoe · #7 10-07-2005, 08:34 PM

I want to thank everyone for their insight/advice. You've made me feel better about my situation. [img]/ubbthreads/images/graemlins/smile.gif[/img]