I still have some 180 Interlocks from my 300 winny. I believe 74 gr of RL22 was the best load for me. Had real good luck with Sierra prohunters, too. I ran the 180's at 3100 and never had a problem. For whatever reason the primer made a lot of difference while I was loading for the 300 Winnie. I had the best luck and the best velocities from the Federal red box, not the match primers. CCI's seemed to give me the least velocity. Winchester primers seemed like they would work on new brass but always had trouble with them being looser after the brass was shot once. Put a Fed or CCI in the same case and everything was ok.
