Can anyone tell me how the Ruger SP101 compares in overal size against a S&W K-frame? I have an old military shoulder holster in which a Model 10 fits, but quite snugly. I want to carry a .357 in the holster, as this rig will be for hiking, fishing, etc., and the added power would be nice. I suppose a Model 65 will work, but a 3-inch SP101 would be lighter to carry. Do you think this would work?