Mauser did not limit their Model 1912 and 1912/14 pistols to just being chambered in 9mm - they also developed a number of prototypes in .45ACP. Today we have a series of three such prototypes showing the sequence of changes in the operating Mechanism used by Mauser. The first uses a friction lever with a buffer, the second is a revised version of friction delay, and the third uses the flapper-delaying system that became standard on the 9mm examples.