I've been using RCBS carbide sizing die. I've read that the steel die doesn't size as far down on the case as do the carbide die. For this tapered case the steel sizer sound like it would work/stress the case less. As the price of M1 Carbine brass is no longer inexpensive this steel sizing might prolong case life and thus reduce cost. It makes little difference to me about case lubing as it necessary either way.
So does anybody have an opinion about using steel vs carbide sizing and case life and function for the M1 Carbine?