I must be doing something wrong because my 642-1 is the most uncomfortable/painful firearm I have to shoot (even with wadcutter loads). My pre-36 with banana grips is much more comfortable to shoot. I would like to know of any tips in regards to shooting a 642 that would make it more comfortable. Thanks.
I'm sure I'm stating the obvious, but the steel J-frames like your Chief's Special isn't going to kick as much as a lightweight J-frame like the 642.
Changing your grips is probably the best thing to try. Have you tried putting the banana grips on the 642?
Grips can be a very personal matter. What works for me may not work for you or anyone else. You have to experiment through trial-and-error until you find something that works.
Having said that, I like Spegel boot grips because their shape fills my hand without being bulky, plus I have the Centennial version where the "ears" go all the way up the recoil shoulder on the grip frame. I prefer them to the current OEM rubber boot grips. However, they can be hard to come by, with a waiting list about a year long for new grips. Eagle, Hogue, Altamont, and VZ make similar style grips.
Grips that cover the backstrap may help, too.
Gripping the stocks hard can also help. I grip hard enough that the gun shakes, then back off the pressure until the shaking stops.
You can also try the really light loads, like Hornady's Critical Defense. While I normally try to stay away from light loads for self defense, if they're what works best for you then that's what you should use.
It could also just be a matter of getting used to it. I carried Federal 125gr Nyclads until I got used to shooting +P ammo. Now I carry Speer 135gr SB-GDHP +P.
Finally, if you try several different things and none of them work for you, it's ok if you decide the 642 isn't for you. Lightweight snubs aren't for everyone, and that's perfectly fine. Maybe getting the all-steel version, like a 640-1, would work better for you.
Just my thoughts on the matter, FWIW.