Yeap .45gap would be the round. They shortned the round so that it could fit in the 9mm & .40S&W size frames. The newest Glock is a Glock 37. It's frame is the same size as the 17/22 allowing people with smaller hands a more comfortable hold on a .45. Only thing I don't like is that the slide is the same size as the 21 with a beveled bottom.