Josh, I have an old military 8X57 barrel on my sporterized Mexican mauser that is about 19" long. The muzzle blast is not appreciable as far as I'm concerned. Of course, I am partial to short rifles anyway. The little Mex is a pleasure to carry and shoot. Loaded with 170 gr spitzers, it seems to make AL whitetails fall down very well.
Weagle, you could shoot any bullet out of your Brno 21F and a deer would be happy to keel over just out of respect to the rifle.....
