Economoically speaking, the USP tactical, Sig P220, or tthe S&W M&P (I think they offer it with a threaded barrel). The Glock doesn't seem to function well with the heavier suppressors, Niielson device or not. I use a 1911 style, but the 16/1 metric threading of the aforementioned guns is heavier (and stronger) than the .578x24 or 40tpi of the 1911 barrels. My early gen AWC Nexus snapped a 1911 barrel threading right off the gun one time, so I am leary of threaded 1911 .45's. Glock threaded barrels abound, but you might never get it to be a semi-auto; it will work as a manually operating repeater, though.