Pretty much no and no.
Contention is that the 124s are better than 147s, doesn't matter what the barrel is the relationship stays the same (velocity vs weight). Until you shoot a live human being (or do a post in depth) you will never know for sure.
Just make sure its a known brand SD ammo and you have done the best you can. No guarantees until you get up to 75mm or so.
You still have to keep the pressure below max and that occurs early in the firing cycle.
There are some rifle powders that allow a steadier constant pressure that stays below max, but a pistol is too short.
Pick 124, 147 or mix them if you want and hope for the best.