I love my Glock 20, and carry it for Black bear. Great choice, knocks a big boar down hard. I've used the .357 mag and never had a problem. The Taurus ultralite .44 mag is excellent for the price, but recoil is very stout and a fast follow up is tough, the ported model is worse IMHO because the darn thing will blow your ear drums out, and anyone near you, and in low light the flash is blinding. With Black Bear your bullet choice will make a huge difference. In 10mm I stick with 180gr Hornady XTP or Buffalo Boar JSP, the Glock barrels are not intended for cast lead and very few .40 cal projectiles on the market are tough enough for 10mm velocities combined with heavy bone. In .357 I use 158gr hard cast gas checks in FP or RN or hot Buffalo Boar Bear loads. .44 Mag gives alot of good bullet selection, and in factory ammo as long as its designed for medium game your golden. Black Bears seem to drop dead fast if you shoot them before they get excited. If they are angry, frightened or wounded they become a different animal and you don't want your gun loaded with self defence ammo loaded with bullets designed for maximum expansion and energy transfer on humans, these will go to pieces on impact, or open so fast that needed penetration is lost. Hope this helps!