155.5 gr in 10 twist

[rmist]

Will this work ... using Berger 155.5 gr in a 10 twist 308 barrel with .168" FB? Want to try them for mid range and reduced targets at 300.
Thanks again,
Rmist

 

[memilanuk]

The freebore is going to be more of an issue than the twist. The 155.5 has a *very* short bearing surface for its length - I've shot them with < 0.090" bearing surface in the neck, and jumping 0.045-0.050" and had good results doing so... but I'm thinking you're going to be jumping them even more.

As far as the twist rate, just don't try to run them @ 3100+ from a dirty/rough bore in high heat with a temp sensitive powder (like N540 in late August in Raton NM). I have seen a few come apart from doing *that* (not my gun, but a team-mate's), but otherwise they shoot great from a 1-10" twist.

 

[rmist]

Thanks for the info !! I was curious....not so much now. I'll stick with the 185's.
Thanks again that's what I needed to read.

 

[memilanuk]

Don't get me wrong... they shoot *very* well. *Amazingly* well. They're just more intended for 0.050-0.085" freebore ('95 Palma / Oberymeyer chambers) than 0.168".

Given how well they jump, it might be worth trying a box just to see. Been meaning to, just haven't had the time...

 

[mao0720]

If you want a 155gr bullet that you can shoot in a chamber with a longer freebore, look at the 155gr lapua scenar. It has a bearing surface very close the the 185gr jugg. So they should both match well with the .168 freebore.