I don't own one, but have handled a bunch of them at gunshows and it looks like a great idea to me. I would like to have one, but it is way down the list. I notice that Wilson Combat has one in their catalog, it looks just like the Mech-Tech but it doesn't say it is one so I don't know. I wouldn't get all hung up on the ballistics of a .45 ACP out of a rifle. It depends on what you are REALLY going to do with it. If you are going to be plinking 99.9% of the time REALLY, who cares. I have a couple 9mm rifles that I use as a Jeep carry gun and a coyote gun. I think pistol caliber rifles are terrific for medium game at real distances (not the BS distances that you hear about after a couple beers). Out to a hundred yards or a little more, it is fine.