I think Sharps also made a 45-90 round with a 2.4 inch length vs the 45-70's 2.1 inch.45-70's will still feed in the 45-90 guns. Makes you wonder how much velocity and pressure are reasonable in a similar weapon with the 45-90 vs the 50-90.The 50-90 sharps is great but a 45-90 would have a larger bullet selection.

You can review the following info and consider suitability-- http://www.practicalmachinist.com/cgi-bin/ubbcgi/ultimatebb.cgi?ubb=get_topic;f=16;t=000913;p=0