Probably get a rechamber.. I got an email from him awhile back. They seem bigger on those .307 bxxlm off the .444 case... I have a 30-30 carbine Bullberry that might get a rechamber, but I have not fully explored the original chambering.. I probably will wait until one pops up in a 14 or 15 inch Contender barrel. Missed a chance at one on EBAY. That one was a JDJ .307 Short and not improved..I got a thing going for Improved chamberings right now. I really like the 7mm SB and oughta be happy with that.. I had a lot of fun shooting and hunting with rounds off the 30-30 case but the .307 case is so much stouter. I have @ 350 new .307 cases. Lots of shots to go. from cbagman