I was using several die reference charts to sort thru some of the misc. dies and found some unusual notations on one chart. The Excel chart appears to taken from the old Lyman handbooks with additional notations in the expanding chamber column. It's broken up into "pistol" cartridges and "rifle" cartridges, so I understand the P & R notations. What I don't get is the M added to the expanding chamber for the 22 K Hornet and the 22 Lovell. These were among the earlies wildcats, but why the M? It's probably academic, but curiosity won out. I used to annoy Rick Morrill with these trivia question but since he's gone dark, ya'll have become my target.