I've been doing a bunch of reading here and elsewhere trying to diagnose my short cycling issues with my recent AR build in 450 bushy. My initial thoughts were that using non-factory magazines was the issue and went through several combinations of magazines and followers without any luck. This week I was able to obtain a factory AR Stoner 5 round magazine for the rifle. I confirmed that an empty magazine would hold the bolt open as it should. When I loaded one round into the magazine, after firing the brass ejected fine but the bolt held open as shown; not clearing the end of the follower in the magazine. I then loaded two round into the magazine, charged one, fired, noticed the bolt closed into battery but upon dropping the magazine confirmed that the second round was still in the magazine.
I proceeded to take the hand guard off to look for gas leaks and the gas tube to gas block and gas block to barrel areas look fine with no apparent leaks that could be causing the short stroking. I removed the gas block from the barrel and also confirmed no major leaks and a fairly decent carbon ring around the port. Using some calipers i was able to measure the gas port size and noted it at 0.0775". From my lurking about this site, it seems that this is small and should be opened up to somewhere in the 0.093" - 0.096" range. Can someone confirm this port size and that I'm correct in thinking this is the root cause of my short stroking issues? Thank you for any help provided, this has been a fun project to build and am eager to see this across the finish line!