One of my A.R. pistols just started short stroking it will not load the next round I pulled the bolt out did the bolt failed change the gas rings and put it back together and it still does it if I swap the upper it runs flawlessly so I know it’s something with the bolt or the gas system anybody have any helpful input when I take the bolt out it stands up without falling down, I have a new gas tube and extractor set I can install it. Literally every time I fire it I have to manually charge it when I swap the upper with one of my other ones it ran fine.I’m considering just buying a brand new bolt and changing the gas tube..