For revolvers it's .327, .38, and .45 Colt, for semi autos it's .32 ACP, .32 NAA, and 10mm.
I know out of those six people are thinking one doesn't belong, and yeah, .32 NAA is a very obscure bird, but the more I look into it, the more amazed I am at how it is being resorted to the scrap heap of failed cartridges when in actuality it is one of the most practical bottleneck pistol calibers around.
While I love 7.62 Tok, the length of it makes the grips for pistols quite large and the same goes for 5.7x28 and both of those are not common, thus brass for reloading is not easy to find at ranges or cheap to buy new. .357 Sig is potent, the problem is I don't see what it does better over a 135 or 155 gr .40 S&W load and brass again not easy to come by at the range.
.32 NAA tho is different, it's a clear upgrade from it's precursor cartridge of .380 in it offers higher velocity with slightly lighter bullet weights in same length barrels. Also, being bottleneck it feeds better and reliable cycling in the tiny pocket pistols is critical.
What I learned recently was that even in longer barrel pistols, the .32 NAA can get a massive velocity boost. On Makarov.com, they have data of .32 NAA Cor-Bon 60 grain going nearly 1500 fps from a 4" barrel. That's several hundred fps more than any .380 I've ever heard of going in a 4" barrel.
What does that velocity do? Well, for one thing it can propel a heavier 85 gr bullet fast enough to expand out of near any barrel length making for a very good self defense pistol that won't be difficult to carry, but with lighter bullets that have a good profile, the .32 NAA has the ability to defeat soft body armor with relatively small pistols, at least smaller than 5.7, Tokarev, and .357 Sig pistols.
) was my brother's .41 Magnum, and it stuck for life. I'm down to 4 revolvers, now... 3 are .41's.
