I've got one of those old 5 digit 3-screws as well. Mine is from 1967, though I picked it up in a pawn shop a couple years ago. That Double Tap Ammo is my "bear load" for hiking. It'll take two hands to keep control, but it shouldn't harm that gun. I can only handle a couple cylinders of that stuff before I download to .38s.
The possession of arms is the distinction between a freeman and a slave. -James Burgh