antelopedundee
Well-Known Member
From working with wild cats for a long time I would suggest that you use NEW cases to start off with. Use a middle of the road powder charge for the cheapest bullet you can find and fire them to form your cases. Great thing about the AI cambering is the case hardly ever grows length wise after the first firing if you do not bump the shoulder back too much.
I agree about the never growing much after fire forming. The other issue is that the case ends up about .015 or so shorter. Some say that this causes or could cause carbon ring buildup. If I was in his shoes, I'd get .270 win cases and put about 25 grains of a fast pistol powder in it, seal with a bit of tissue and fire away. The case should chamber with no issues. It may be necessary to trim back to the regular .06 length of 2.494 inches. That way you would never have cases that are always too short. It may not matter much to the OP however.