The first thing I think of is to use the same bullets for both. After all, when you're into pussycat .38 Special loads there isn't going to be much difference in recoil.
If the 125 has conventional lubricants the drawback to crimping in the bottom groove is that you will have lube exposed to pick up crud. You might also need to adjust the load up a bit if velocity matters.
I'm assuming that you have a lever action .357 and it won't feed .38 Special length ammo. Overall length is always an issue with lever actions and it might be easier in the long run just to use .357 brass for it.
If the 125 has conventional lubricants the drawback to crimping in the bottom groove is that you will have lube exposed to pick up crud. You might also need to adjust the load up a bit if velocity matters.
I'm assuming that you have a lever action .357 and it won't feed .38 Special length ammo. Overall length is always an issue with lever actions and it might be easier in the long run just to use .357 brass for it.