No need for us to debate the small differences, there are thousands of websites that already do that. We're on the same page for the most part. The important part is get the right gun that's right for you. Even a 22 can be very effective and better than nothing for sure. All have compromises. Well placed small caliber pattern is much better than a wildly placed large caliber. Unfortunately the only thing small enough that I would actually carry is a 380, basically every other gun on the market is significantly heavier/larger and thus less practical on the bike. The revolver you suggested is not practical to draw from a jersey pocket, due to its width and the hammer likely snagging.Unless you want to carry a fanny pack! Anyway there's tons of info on the web that would be better than a triathlon site ;-)