Originally Posted by demon
OAL is too short.
Technically, it is due to the case length being too short rather than the overall length. Straight wall pistol calibers use the case mouth to properly position the cartridge in the chamber. Using a 45 GAP cartridge in a semi-auto chambered for 45 AUTO can result in either the cartridge being positioned by the extractor (which is neither good for the extractor or barrel) or the cartridge being seated too deep in the chamber (which likely means that the extractor is no longer engaged with the case, meaning no extraction, and the risk that the primer is positioned too far forward to be struck properly by the striker). The shorter OAL does present some potential issues regarding feeding.
Since the OP refers to "hydroshock" <sic>
, one could assume the ammo was purchased for defensive purposes. Even if
a 45 GAP round functions, reliability would be a MAJOR concern.
While 45 ACP is fairly common nomenclature in this forum, most ammunition manufacturers use "45 AUTO" on the boxes and on the headstamps.