That depends if you want a true backup or a secondary hunting pistol. If I'm after deer it's my 45colt SBH Hunter on the belt and my 7 08 Encode on a sling holster. The gun I use depends on how far the shot is.

When I want a backup for gun or bow hunting it's my glock 29 with a lone wolf extended barrel. I get the same ballistics as a glock 20 with an extremely small shootable package. Plus I don't have to care if it gets rained on or banged around the brush.