05-13-2021, 03:20 AM
SDW Wrote:Ah, thanks. I actually have brass punches too. Smallish ones. I use them all the time for driving in roll pins, etc. Plus some aluminum bar stock that I could have used I suppose. I'm starting to wonder if I really cared about that gas block now. LOL It leaked gas pretty bad, IMO. It was open at the front. Below are a couple of "before" pics. You can see how it was spewing black gunk all over the barrel at both ends. I know it's not supposed to be a perfectly tight seal, bug this struck me as inefficient as well as kind ugly looking. I replaced it with a BCM GB. Closed at the front.
[ATTACH=CONFIG]17846[/ATTACH] [ATTACH=CONFIG]17847[/ATTACH]
That gas block looks terrible. The gas tube port side should be around .180 .181 to .182 in size, if memory serves. The gas tube end should be .180 as best, .177 as fair and .176 as poor in size. BCM gas blocks have worked well for my builds when an adjustable was not wanted.. The gas block journal opening and barrel journal size difference is also important for gas seal. Gas leakage from the gas block, gas tube, gas key, bolt carrier three chambers, under powered ammunition, and wrong buffer system can create problems with a correct sized gas port..Throw in an incorrect cut chamber, throat, under or over sized barrel port, tolerances at opposite ends with the receivers, fire control group, barrel extension, weak extractor, weak or clogged ejector, over strong extractor, clocked barrel, clocked gas block, poorly manufactured buffer tube, incorrect bolt carrier length, etc and it can be even more fun finding the problem with a malfunctioning AR..