.45 is not a good caliber for SSP, or the obvious USPSA counterpart, Production. Both sports reward 9mm chamberings in their "stock" divisions. If you do want a U.S.-made .45 that's legal, I'd say there's not much other than the Smith & Wesson M&P, a couple of Rugers, and the Smith & Wesson 3rd Generation autos, the last of which aren't even in production anymore IIRC. Of course, all those guns are also legal in other IDPA and USPSA divisions, where their caliber/power, and perhaps capacity limitations aren't issues.