Has anyone slugged the bore of a M10 280 Ross rifle and checked the twist rate?

I have just done this in preparation of having some monolithics turned up for the old lady - and am a little puzzled by what I found.

So a confirmation would be nice.

cheers edi

I believe the old .280 Ross cartridge utilized a bullet that measured .288 or .289. This was consistent with old British practice. I belive a company in the U.S. called Hawk Bullets makes bullets specifically in this diameter.

Hello P-17 - thanks for the post.

The bore of this barrel is in "as new" condition. I slugged it and measured the bore as 0.2806" and the grooves as 0.2904".

I made a die that I use to "bump up" 0.284 heads. I was aiming for 0.288" as per the literature but over-polished it and ended up with bullets that measured 0.291". Initially I worried about it but they shot just fine. Should have started by slugging the bore. Just lucked out I guess.

OK - now who has checked the twist rate?

cheers edi