My Hiking, Camping and Field gun is a 3" M65. While in Bear Country I stoke it with Buffalo Bore HEAVY 180 grain Hard Cast Semi Wad Cutter .357 Magnums. 1,300 fps from a 3" barrel. Almost 1400 from your 4" tube. For a 180 grain bullet that is serious medicine.

For two legged animals Buffalo Bore Heavy 158 grain +P 38 Special #20A LSWCHP-GC is what I use. Out of a 3" tube it will give you 1,150 fps and almost 1,170 from a 4" tube. Because it's a .38 special you will NOT get the violent recoil, muzzle flash and loud report of the Magnum. Also gives you much better recuperation for a follow up shot and more control.