Is your 625 a dash 6 Mountain Gun? I got my 625-6 MG in
.45 Colt new from the dealer already magnaported. I also always wondered why they ported a .45 Colt.
SAAMI spec .45 colt is pretty anemic (14,000 psi, 15,900 CUP) in recognition of some of the older original black powder era revolvers chambered in .45 Colt.
Some handloading manuals have “Blackhawk and T/C Contender only” loads that run around 25,000 CUP or 22,000 psi. But those loads should *ONLY* be used in those handguns, not in a S&W, even an N frame that has a .44 Magnum counterpart as the steel in them is heat treated differently.
I do shoot some .45 Colt loads in Winchester 1892 and Rossi 92 rifles, as that action is essentially a downsized Model 1886 and is incredibly strong (Rossi used to chamber their 92 in .454 Casull) that approach .44 Magnum *performance* - but at a lot less than .44 Magnum pressures. The data for those loads is around 32,000 CUP, roughly 30,000 psi and well below the 36,000 psi max pressure for the .44 magnum.
I bring that all up as magnaporting a 625 chambered for .45 Colt would seem to encourage the use of higher pressure loads, which is a really, really, bad idea.