Will a .300 Weatherby Mag reamer clean up a .300 H&H Mag chamber? The only dimensions I have show the H&H with a larger neck diameter and slightly longer overall length.Thanks for any help.Frank.

The answer is yes, eventually. But in one shot? It would depend on the dimensions of the actual reamer to be used vs a chamber cast. It is going to be close. While it is possible, it is close enough that I wouldn't take the job unless I were allowed to take a thread if needed.