So i'm putting together a stash of spare parts for my AR and i have a few questions. How long do bolt gas rings normally last? Do they wear faster in a carbine length gun? Can anyone tell me about one piece gas rings? Seems like the three piece rings work well enough but..... Also, do buffer springs ever wear out? I've seen upgraded springs out there (chrome silicon,flat wire, extra power etc.) but dont know if thats something i should consider. Any advice would be appreciated.