However, he used the number drills and picked out a number slightly bigger than the existing hole. If that did not work he went the next number up. He didn't just pick out a drill bit he thought was OK and use it. A 1/8th drill bit is .125" diameter hole. I think his final number was in the .090 range. .125 is probably going to over gas the rifle. Find someone with the numbered bits and work up from the existing hole until the gun is reliable.
kwg
Yes, this. Small changes in gas port size, like going from .086" to .093", can have a big effect on how the rifle runs. One would have to be completely oblivious to this stuff to suggest drilling out to .125" without a lot more info and testing smaller port sizes first.
