Rod - FYI - the .458WMag. 2 1/2" reamer wouldn't work without the belt cutter portion being ground off, then it would need to be plunged more deeply when reaming to get the 2.85" length. Then, the normal shoulder at the end of the chamber must be ground with a special reamer to an angle from the case mouth to the leade/freebore, without any case mouth shoulder remaining - THAT aspect of the chamber was the only difference between the old .450 Watt's chamber and the .450 Lott chamber. The absence of the inner shoulder allowed shorter .458's to be fired without shaving bullet metal on that mean little shoulder - that's it. The actual ctg. has been around for over 60 years in the .450 Watts - and a good one, it is.