Sorry for the necro. Assuming you're referring to the revolver I'll report my experience with bears in my most recent game on stalker with the revolver.

So far I've killed 9 bears, 7 from bleeding. The last kill however I cheesed by killing it while standing in the veranda that the farmhouse in PV has on the south side. 15 rounds, 12 hits, level 4 revolver skill, going for the head when possible. Based on that experience and my encounters with wolves it's my opinion that the revolver is best for close wolf encounters. Save rifle rounds/arrows for bears, unless you want to bleed the bear out. Oddly enough every one of those 7 bleed kills with the revolver have been from just one shot. Mainly killing them to make the area safer to traverse. So it seems that the revolver does pretty decent bleed damage, but damage per shot is for obvious reasons lower than the rifle. Unsure about how it stacks up against the bow, but my gut feeling is somewhere between the rifle and bow for bleed, but lower than either for damage per shot. Took me 28 hits to bring down a moose in this same game, whereas with level 2 rifle I downed a second one in 5 shots.