I've tried some bullets in that range 120-121 grains a long time ago. Fwiw I've shot everything from 88gr jhp to 150gr lead through open guns. No the 88-90-95 grain bullets weren't at major pf but for a minor load they're AWESOME! One of my favorite bullets is the factory 130 fmj .38 super bullet. It's a .356 bullet and shoots pretty good in most of the guns I've tried it in, but it's hard to find now. Recoils wise there just isn't that much different between a 125 and a 121 and I really like the accuracy I'm getting with the 125 Zero. I understand that some are getting pretty good accuracy out of the 121 Hornady TAP bullets but they are expensive and hard to find in bulk from what I hear.
I would experiment with different powders and see what you get first. I pretty much just stick with my standard load of 3N37 under a 125 zero bullet, I've been using this for a long time now. I usually factor around 170-172 and it prints around an inch @ 25m with Starline supercomp brass. If I'm tight on money I'll use IMR 4756 and I still get good groups but it's much more temperature sensitive. I've tried 3n38, n350, n105, Autocomp, AA#5, AA#7, win 540/hs6, and probably some I've forgotten and I pretty much stick with 3n37 or 4756....though I'm a bit low at the moment and I have some Autocomp in stock so I might shoot that at Nationals...