Ar-15 gas block

[Chontkleer]

Got rifle back from the gunsmith who had replaced the A-frame sight post with a flat top railed gas block. Took it to shoot, and it no longer extracts. His comment: oh yeah the hole on the new one is bigger than on the old one.

Snarky comments welcome, but suggestions on how to proceed even more welcome.

[FeuerFrei]

"gunsmith" induced gas leak. rookie move and no QC.
alignment of bbl gas port and gas block. not installed correctly.
take it back first to have them fix it.
if gas block is installed with cap screws you can loosen them up and move the block until it aligns.
canned air is good to check the flow thru the gas system.
this is basically an easy thing to fix in most cases.

[Chontkleer]

Thanks Feuer. Will try to find more more info on using air (you blow it through the system and know it's right when it comes out full force?)

[molasses2k]

Or the gas block gas port hole could be not lined up with the hole in the barrel or the gas port hole in the gas tube. I just had a thread about this stuff... either way lame not to to test-fire the rifle to confirm proper operation before returning it to you-

With compressed air blowing down the muzzle and a cartridge loaded the BCG should move back in the upper signifying that the gas is getting back to the gas key

[Chontkleer]

Or the gas block gas port hole could be not lined up with the hole in the barrel or the gas port hole in the gas tube. I just had a thread about this stuff... either way lame not to to test-fire the rifle to confirm proper operation before returning it to you-

With compressed air blowing down the muzzle and a cartridge loaded the BCG should move back in the upper signifying that the gas is getting back to the gas key

Is canned air like the ones to clean computers good enough or do you need a compressor/hose like you find in a repair shop?

[Chontkleer]

Welp, that turned out to be easy. Had the rifle out today. I took off the block again and noticed there was what I thought was a burr next to one of the screw holes. Wife picked it off with her fingernail. It was a clump of loctite. Then I noticed that the surface of the side that sits on the barrel was uneven. More loctite. What the guy had done was put the block on the barrel, in the wrong position, smothered in loctite, and then he screwed it down, but not all the way. All I had to do was scrape away all the gunk, move it into position by eyeball, and then tighten it properly.

[kcstott]

One more reason that all gunsmiths are not created equal. What a dip dunk.