My regular work weapon is a Browning HP, my BUG is a 940 and I carry 2-3 extra moon clips. I can also thumb load the 940 from the BHP mag of the BHP goes Tango Uniform.
My daughter drives F-18s off a big boat, she carries the issue M9(Beretta 9mm), but she is also packing (my extra) 940 which she carries in a holster sewed into her survival vest, she packs several extra moon clips (as well as 3 extra M9 mags. The moon clips ride in a aluminium tube that fits them perfectly that a Machinists Mate ginned up for her. She also packs a S&W auto knife, that she can sharpen to a razor edge, and a Randall #2 that I gave her when she got her wings.
Her brothers (also military aviators) theorize that the way to end any war quickly would to get her on a bad PMS day and drop her behind enemy lines, then just wait for the enemy to come running to surrender.
In any case the 940 is obviously my choice, if I were carrying other than a 9mm "big" gun, then I might think of a revolver that shot that cartridge, or a 640 in .38 special if matching calibers wewre not possible.