Does anyone have one or done an UMP conversion on a USC llike tactical excellence has? Are they legal?
Unless it's registered, in which case the mod would be legal as long as the length is over 30"As long as it doesnt have a pistol grip, folding stock, flash hider or forward grip it should be OK.
You can have all that stuff with a pinned 10 round magazine and load from the ejection port.
Either way, it must be over 30 inches.