Just dialed-in my brand new Winchester M70 FWT in .30-06. So far I've determined that it doesn't like two things: (1) Federal Fusion ammo (165 gr. Hornady SST seems to have worked the best so far) and (2) a hot barrel. No kidding guys, if that thing's even remotely warm, you're probably going to get a stray round (by about 1-2 MOA).
Has anyone shot better groups (i.e. sub 0.65") with 150 gr. rounds? If so, what type?
First of all many LIGHTWEIGHT barrels throw shots after they heat up..
Factory or not.
It's hard to get a contour much lighter than a Winchester featherweight.
I think your rifle shoots dam good for a barrel that light with a .30 cal hole in the middle.
Having said that, have you checked the barrel bedding? Make SURE it is fully floated. Run two new dollar bills down the channel between the barrel and the forend. Check and make sure no nibs of finish and sawdust etc are touching the tube.
When a lightweight barrel like that gets hot and expands, anything touching the barrel can cause funny things to happen..
