I surely agree with a .32 for small game. For trails, that is, trail walks that give you a score, I'd draw the line at .45 or above. Don't get me wrong, I truly love my .40 & use it for trails, just as Taylor does - BUT - as the fellows you shoot with get older, longer in the tooth and harder of hearing, not to mention failing eyesight, you'll "lose points" if shooting a .40 on many trails with fairly heavy gong targets. If using a .32 on a trail, I wager you could count on at least 1 point per 25 shot trail & maybe 2 sometimes. Much depends on wind, sounds in the trees, the 'friendly' talking by those you're shooting with, hecklers, etc. On heavy 100yard targets, the .32's little 42gr. ball doesn't make much noise, nor does it move the gongs much. some move, but not all, even though you ro someone might hear a faint short 'tink'. Always good to have young people along. HA!
That said, using the .32 or .40 on the trail is more challenging, mucho fun, especially on cutting cards with one, really shakes them u,p but a .45 is much easier imho and a .50 if fed well is the hands-down winner on trail walks- again, imho. Some of our guys do exceptionally well with their .54's as well and there are times when even larger bores like a .58 or the 'Gentle Lady' wins. She's very persuasive in making targets swing so there is no doubt of a hit. I have fun with that one every rendezvous - with the re-bar tri-pod mounted steel gongs - lifting them up into the air on the single rear leg then they plop back down. It's all fun and games, so depending on whether it's just for fun or for winning, makes the choice more important.