I don't have a Hi-Power and I don't pretend to know what is going on.
Sometimes when something (Or Someone!! ) starts getting old multiple issues come together at the same time.
Its still good to make one change at a time and evaluate the results.Otherwise its hard to learn what helped.
Obviously cleaning the extractor/slide was a good suggestion.
I watched a youtube vid once by one of the Philippine 1911 makers. He demo'dhow ,as you load amag then push down on bullets,follower tilt can occur.Improvements have been made in followers,and I'd guess double stack 9 mm followers,too.
Springs fatigue like shocks in a car. They don't seem so bad till you get new ones. I'm not suggesting heavier springs. Just newer ones.
Magazines get dirty the same way extractors do.A disassembly and toothbrushing in a coffee can of mineral spirits can do wonders.Observe spring orientation.A light spray with some dry graphite or moly lube wont hurt. Like the stuff locksmiths use. Nothing that sand sticks to or gets gummy.Friction inside the mag with a tired spring can funky up your stack.
