For Taurus large-frame .45 Colt revolvers, assume that these guns are safe for SAAMI-spec loads only, since Taurus isn't talking, and the tolerance in dimensions is apparently loose enough that I wouldn't be willing to trust a Taurus past 14,000 CUP.
for most purposes, a 45 colt +P load is considered to be in a maximum load in 44 mag or a very low end load in .454 casull.
Whoa pardner! Before you go shooting off your '+P' loads, let me go hide behind this here barn, in the next county. A typical maximum Ruger-only .45 Colt +P load should only develop 80% of the pressure of a maximum .44 Magnum load since, all things being equal, the typical Ruger .45 Colt cylinder is a .44 Magnum cylinder with bigger holes bored in it. Ergo, less metal to contain the pressure. Rugers have been scientifically tested to destruction, and the cylinders gave way at 80% the pressure that .44 Magnum cylinders gave way at.
Similar dilemma when looking to buy a 45 Colt lever gun. Wanted to be able to shoot "heavy" Colt 45 loads, but knew most of the 45 lever guns were more in the "cowboy round" range.
A quick guideline(*) here is:
- Winchester 1866 and 1873 clones, Uberti 1860 Henry clones, Colt Lightning pump-rifle clones and look-alikes, and probably any rifle with dual-purpose .45 Colt/.410 bore barrel: Strictly SAAMI-spec loads only.
- Marlin 1894 and Winchester 94 rifles. Henry Big Boy rifles. H&R .45 Colt single-shot (the one patterned on the .45/70 Buffalo Classic target rifle) and Browning Low-Wall .45 Colt rifles: Hotter than SAAMI-spec loads, but not as hot as the top-end Ruger-only loads. I don't like exceeding 27,000 CUP of pressure here.
- Winchester 1892 clone rifles such as the Rossi/Legacy Puma (
not rebarreled original Winchester 1892s!): Ruger-only top loads, and beyond. These are the only .45 Colt rifles I'd even think about developing stupendously heavy loads in.
* - Only a (semi)-informed opinion. Use at your own risk!