Hi,
I have a 357 Talo (maxi, no longer a mag) and I have zeroed at 25 yards for squirrels. Bit of overkill I admit but one big hole to me is a lot better than picking out #6 shot. Anyway, I have been shooting 180 grain Hornady HP/XTPs over 19 grains of H110, which is a couple of grains below max load. The round comes in an inch or so high @ 100 yards with the 25 yard zero. Using a cheap 4x scope with "high" rings so about 1.5" offset between centerlines of bore and scope. I just loaded some 125 grain HP/XTPs over 20 grains of H110 and w/o a scope adjustment the rounds impact about 4" below the bullseye @ 100 yards. Also the group is not so good with the 125s, but the powder charge is light, a bit below starting load if I remember right.
I personnally would not use the HP/XTP bullets for deer as they fragment on fox squirrels.

Yes, I know many folks use them in CFs and saboted MZ, just my biased opinion.
Okay, now to try and answer your answer your question, if you are zeroed @ 100 yards with a scope you should be good to 125 yards. The slow buckhammers I shoot with a scoped shot gun when zeroed @ 100 yards will hit about 3" low @ 125 yards so your 357 mag should be about the same.
The first two paragraphs was my attempt to get you to rent the 357 Max Reamer.

good luck hunting this fall.
BB