It's a 45 2.3, as it turns out the good folks in Italy that chambered that rifle musta had one screwy demensioned reamer. It's marked 45-70 but lacks about 1/10 of an inch of chamber 45-90's. So to keep leading issues down and other associated problems of short cases, I trim cases back to 2.25, Norma basic makes good paperpatch cases, Starline 45-90's are good for greasers.
I also have shot the throat out of a Ruger 1a in 3006 using it on everything from mice to moose..