To share: I had often wondered what weapon(s) T&T 93, though designed for the Greene Carbine, had actually been used in during the American CW. If fired from an actual Greene Carbine, it should evidence 3x3 rifling (per M&M. p. 168). According to "Flayderman's Guide to Antique American Firearms . . .," (8th Ed., pp. 510-511) some .54 Greene Carbines produced by the Massachusetts Arms Co. made it into the hands of some Federals (e.g. 6th Ohio Cavalry). Flayderman's also writes, "Legend has it that a number of the British Type Greenes were repurchased by the U.S. during the Civil War, but there is no substantive evidence of this." In any case, a few years ago I purchased a fired T&T 93 (dug in the Shenandoah Valley, VA) that has 5x5 rifling marks. The possible suspects (with 5x5): .54 Starr, .54 Burnside, .54 Ballard, or a .52 (.54 per M&M) Terry (Calisher & Terry) Carbine English breech-loader. It has been interesting to wonder which fired this bullet. If I had to place a bet, I would probably put my money on the Starr (and I think I would bet against the Burnside).