Ruger MKII bull barrel. Very reliable and very accurate. I don't even think I have failure for over 10,000 rounds. I did break the main spring housing ( about $7 to replace). It is cheap to shoot and I don't feel any difference shooting between 45 and this one in terms of accuracy and speed. I don't know why so many people talk about recoil issue, to me, sure, the 45 kicks more, but so what? I literally practice with the Ruger and only once on the 45 before competition.
Ha ha, you want to complain about recoil, try shooting a Freedom Arm .22Mag with 1" barrel. That's recoil. I still can comfortably shoot with one hand.