I'm looking to build a 270W on a Win 70 receiver, the difference on this one is that it will be the first I've done with a Proof carbon barrel. The only Proof blank I see available in 22" (will be using a suppressor) is 7.5 twist which I'm afraid may be too fast for the 140-150s I intend to use. Can anyone offer any insight on this option?
I like the .270Win from a component availability perspective as well as the reliably smooth feeding that long sexy tapered case gives. I have a 22" 1:8 Lilja in 270Win on a Kimber 84L Montana. I've really only used 2 projectiles for accuracy/hunting (I'll use any old thing lying around for Fire-forming new brass). The 2 I've used are the 150ABLR @ 3K fps and 140gn Badlands SuperBullDozer @ 3075fps. Accuracy is excellent with both. The 140 Badlands gives me a bit more BC, an extra 75FPS, and less recoil (the 150's are snappy in a 7.25# all up package).
There's not a big-game .277 projectile made that would give me pause in a 1:7.5 twist. Perhaps some of the lightweight varmint bullets might go "poof" before they hit the target, but, anything actually made as a projectile meant for deer and larger should be just fine in a 270Win.
Using the M70 action I would:
1. Obtain a "magnum" length magazine or have someone remove the spacer to lengthen the box magazine COAL capacity from 3.34" to ~3.6"
2. Replace or shorten the bolt stop and ejector accordingly.
Using the Kimber, I'm locked in @ 3.34" COAL and those 140 Badlands are seated a LONG way into the case and are a country mile off the lands. As it turns out, it shoots them just fine, but, I certainly didn't stack the odds in my favor from the get-go.
