jtb1967

I'd be curious what kind of velocity loss you may be getting with those bullets. You've got to have some gas blow.

I know it used to be popular to take Type 99 Arisakas and rechamber them to 30-06, but the .308 bullets were well under sized. The one I fired wouldn't hit the side of a barn. I've heard similar reports from a local gunsmith.

Briman

Probably some. On the other hand, the bullet metal that is displaced by the lands has to go somewhere, probably fills the grooves.

I've heard the same about 1909 argie rifles being reamed out to 30-06. I guess your milage may vary and each rifle shoots differently.