imported post
AbNo wrote:
It would most likely vary from gun to gun, mag to mag, or even cartridge to cartridge.
Let me know how that micrometer checking went out.
My experience is not with a micrometer, but a digital caliper applied to Fed Hydrashocks carried in a G17.
I few years ago I heard about the issue of rechambering shortening rounds. I had not, for a while, expended any of this pistol's carry ammo at the range, but had unloaded/reloaded the same two cartridges alternately in the pipe before and after each range session, maybe ten to fifteen sessions total. Drop carry mag., unload, range session with practice mags, load from mag., drop mag., top off with cartridge pulled in step 1, etc.
When I checked, I found the top round was about 1.046", the second about 1.052", and the rest of the mag. was between 1.1" and 1.102" inclusive. I believe that min. OAL for the 9x19 is 1.050".
When I fired the short round shortly after this, taking care/paying a lot of attention, it did not seem to be any more energetic than the rest of the magazine, nor did the pistol blow up. I now pay more attention to this issue, and "rotate" carried-in-the-pipe rounds in all my self-loaders, as well as try to be less thrifty about shooting mags full of expensive carry ammo regularly.