What twist for a 280 AI?

Shooting 140 grain Nosler Accubonds.

An immediately available option is an 8.7 twist.

24" Bartlein #3 plus Vais brake screwed into a 700 is where I'm headed with this.

Thanks.

Go with the 8.7 it will stabilize anything your likely to use in your 280 AI...

This. ^^^.

. I have a Benchmark 9 on mine and it will easily run 162ELD's. And once the 180 show up I'm sure they will be fine as well.

I'll second, or third this ^^^

I run a 9T. Can't see a 8.7 being a bad thing..

The 8.7 should shoot everything but I would lose the brake or at least get a thread protector. Only reasons I could see for a brake are if you are trying to call your own shots or had a physical injury. Bartlein #3 is pretty heavy like most others #4s so should tame barrel jump on what is not really a hard kicker.

Mine has a 1-10 twist because of a good deal and shoots up to 160 grn, bullets just fine. If I want to use 175 or 180s they go in a 7RM with a 9 or faster twist.

1&9 was my choice and would be again if i build another

1 in 9 on my Jarrett. No issues with 140's and 150's.

1:9 on a Bartlein 2B, on 2 different rifles. Both throated for 140 AB's. I wouldn't change a thing.

What reamer, how much freebore? Trophy grade ammo or handloads?

1:9 is plenty for 140's and beyond. Bugholes.com seems to be stocking more and more of the 1:8.7's lately... no issue with those either.

I went 1:9 on a bart #3 @ 25". 0.100" FB to setup the 168 VLD's.

http://www.longrangehunting.com/forums/f53/ts-customs-280-ai-163123/

8.7 will work fine, it's more than required for a 140 accubond but it doesn't hurt anything and gives you options for heavier bullets in the future. If the barrel meets your other criteria then grab it.