Not looking to get flamed here, but if you try to install the regular ones into a 15-22, you're going to have to flex the lower receiver inwards to make them snug - a process sure to bring results worse than you might have had in the first place. Buy the correct ones for the 15-22, and they fit perfectly. There is a significant (not inches here, but the difference matters) difference between the length of a typical AR15 pin and the 15-22 pins, especially when you're trying to attach something to it from outside the receiver.