Sometimes I make myself feel stupid

I like it, better all the time. Don't feel stupid feel educated. Something else your father always says, "" every lesson in life has a cost in blood sweet or tears"" I may now have to add to that humiliation.
Being now aged I have an excuse for repeating the same mistakes which I admittedly at times do. One is a similar problem as to what you just had but with Ruger revolvers.
The issue is that I can be happily plinking away with a simple youthful joy when suddenly my miss ratio begins to exceed my hits. To correct the problem my mind goes through the list of possible corrections with adjusting the ammo, cleaning the gun and concentrating on my grip hold and trigger pull all to no avail.
Then finally my well worn memory catches up and I remember "oh yea the grip screws".
Without fail on checking the grip screws I always find some or all to be loose. Tighten those down and suddenly I am a pretty fair shot again. There are five screws that connect the grip frame to the revolver frame and all must be tight or upon shooting the revolver frame moves independent of the grip frame causing poor grouping even though the hold, sight picture ,and trigger pull was good.
You would think that this would be quite an easy lesson to learn and something to first check at any sign of irregularity in grouping, YOU WOULD THINK but seemingly it is regularly the last thing done to correct the problem. Getting old is not for the timid or weak of heart !
Maybe too I need to add still a fifth  category to my quoted saying in that lessons learned can also have another cost in ammo because I have more than once burned up plenty attempting to solve a problem that is easily corrected by the slight turning of those five screws. Stupid? No. Educated ? Working on it !