I've been around for a while and have used firearms all my life from the time I was old enough to walk and shoot and be trusted.
I've owned many rifles and have known of many others that friends and relatives owned, and we used them a lot and mainly as hunting tools.
If we couldn't shoot a squirrel in the head at 100 paces we got rid of it, no matter what caliber it was, and there was no way my brother or I, were going to allow the other to "one up" each other, when it came to shooting!
That may be a stretch, but we were pretty good at estimating yardage back then, and surely better than today!
Very seldom did we tinker with one, once we found one that would shoot!
Times change along with my eyesight, and and now I try to do what I can to make them better, but that original mind set is still there.
Once I'm satisfied that I have a shooter, it stays the way it is!