45LC+P is NOT the normal "+P" case. Most of the time "+P" means "10% extra pressure". 45LC+P means something else entirely! Here's the breakdown:
45LC Black Powder: Colt SAAs prior to about 1895 had cast iron frames and weak cylinders. No new-made guns are limited to this that I know of, except for maybe cartridge conversions of open-tops.
45LC: standard pressure is 14k. The only guns limited to this are old-fashioned breaktop types, and Colt SAAs made before WW2. Closed-top cartridge conversions (Ruger Old Army, 1858 Remmies) can cope at this level.
45LC "Modern" loads: in any sane world these would be +P, except that these came AFTER the +P loads below. These "modern standard" are OK in Colt SAAs from after WW2, the Ruger New Vaquero, the various Italian solid-frame Colt SAA clones, etc. Loads involve 200gr JHPs/JSPs doing 1,100fps, or hardcast 255s doing 1,000fps. Pressure peaks at 22k. *Probably* fine in a Bond Arms. A good clue is, if the gun also ships as a 45ACP (peak pressure is 22k) the same gun can cope with 22k 45LC loads. Cor-Bon calls at least one of these loads (their "combat load" 200gr JHP) "+P" - incorrectly in my opinion.
45LC+P: pressure runs as high as 33k. These are meant for 44Magnum-class guns with cylinders heat-treated to 44Magnum specs. Originally that meant the large-frame Ruger single actions, later expanded to the Colt Anaconda, Magnum Research BFR in 45LC and Thomson single-shots. The later-gen S&W model 25s can handle 25k or so, and a few of the Cor-Bon real +P loads from the hunting part of the catalog are compatible with these specifically. But for the most part, "+P" excludes all the S&W N-frames. If you shoot +P in a Bond Arms derringer you are nuts.