Apparantly there are some different lengths out there. This was a new one to me! I measured 12 different CMs and came up (measured from breech face) between 3 1/4" and 3 3/8". The slides all measured the same. The difference being on the 3 3/8 barrels, the barrel stuck out 1/8" past the front of the slide. Learn something new everyday! Thanks for the insight! Brad