Sorry your loads are having problems and more so that you new(er) 45 is too.
Did you have any problems with the first 96 rounds fired?
I would suspect that your load of 4.2 grains of 231 is just too light.
What did the primers look like? Did the brass seal well in the chamber?
My copy of 'Modern Reloading' by Richard Lee list a starting charge of 4.8 grains of 231 with 230 grain Jacketed bullets.
I normally load 200 grain lead SWC with 5.6 grains of 231. This is a stiff loading and is safe in my weapon/s with my components (846fps from my 5 in bbl and 970fps in my 16.5 in microgroove Marlin - yes lead runs quite well). I use this as only a point of comparison with your 4.2 grains. That's 1.4 grain more, 1/3 more.
My advise is edge up a bit from the 4.2 grains. Watch for pressures and take care.