This same question comes up ever now and again when someone new arrives here or on other boards.
The last time it did, for myself anyway, I called S&W Customer Service.
After waiting for what seemed to be forever, I spoke with a male tech who when asked the question by me of using .45 Super ammo in a M625, asked this question,
"does it say .45 Super on the gun or the box it came in?"
I replied by saying that all it was only marked .45 cal. He replied that that did NOT mean SUPER and asked me,
"why put undue wear and tear on a fine gun by using ammunition that generates pressures that it was not intended for?"
The tech further commented that S&W, at that time, had no gun in their line that they would recommed the use of .45 Super ammunition in. Very close to his words anyway.
My M625 is an original 1989 5" model that I bought in '89. It shoots very, very well as do most 625's.
I have many years of shooting under my belt with both revolvers and semi-autos and know for a fact that the use of higher pressure loads will loosen either in a shorter time period than using ammunition loaded to "normal" or "standard" specs.
I wouldn't think of using .45 Super ammo in my 625.
A coupe of years back, I was told by a personal friend on the higher levels at HK that the use of .45 Super ammo in the USP line of guns would
VOID any warranty on their guns.
They had several USP's come back to them with frame damage due to the use of .45 Super ammo and they refused to warranty the frames on those guns.