I have a gen 4 Glock 34. It has 15-20k rounds through it, and lately the brass is ejecting and dropping at my feet. I have not had a malfunction but afraid a stovepipe issue is in my near future. The extractor spring, extractor, and recoil spring are all original. I am guessing one of these may be my culprit. I am shooting the same power factor as I was some time ago with better ejection. What parts should I look at to fix this??