Fix this or leave it?

[No Bananas]

A while back I got a 12.5” Noveske chrome lined barrel - the gas block install was monumentally more difficult than anticipated. I smacked the bottom of the gas block more than a few times, and yes, ended up putting a sharpie to it to cover up my embarrassment. I finally, barely, got the pin through. No matter how hard I pounded with my biggest hammer and roll pin punches, I couldn’t get in in any further.

Put a few hundred flawless rounds through it, accuracy is about 1 MOA, and I didn’t shoot it for a while. Recently, I took it out and put a few hundred more rounds through it - everything from surplus 5.56 to PMC and match ammo. It has never malfunctioned (carbine spring and H2 buffer).

Every few boxes of ammo (regardless of type), I’d get a wild group - like 4” at 50 yds. I have a CMC 3.5 lb trigger and usually do my part shooting from the bench. These big groups left me scratching my head a bit, and I’m wondering if my gas block hack job is the culprit.

Question - should I send this upper to ADCO and have them take off the gas block and and properly install a new one? Or are the intermittent big groups par for the course and I should just stay the course - I don’t think the gas block pin has moved at all and I haven’t had a single malfunction. See pics below.

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[MistWolf]

Your problem is unlikely to be related to your gas block.

[AKDoug]

There really is nothing wrong with the position of that pin. They should be tapered and that's where it stopped. Done deal. Like MW says above, I don't think it has anything to do with your weird groupings.

[markm]

Noveske reams their tapers too shallow. It's irritating. Pappabear had a fixed FSB 10.5 where the pins hang out, and it looks bad.

Agreed that this has nothing to do with bad groups.

[pinzgauer]

Had a DD pre-reamed barrel/gas block do the same.

Bugs me visually, but shoots good.

[MQ105]

It doesn't look like it from the pics, but could the GB be touching the handguard at times? Possibly the way you are resting/pushing the gun certain times? Torquing on it with a tight sling? Otherwise, the GB wouldn't cause intermittent accuracy problems.
The only other consideration I can think of is your eyes/sight. I know my T-1 dot looks like an oblong smudge to me at times. Other times it looks round and (mostly) clear. Are your eyes starting to change?

[Deadsquiggles]

Like it’s been said above, the taper pin will stop when it’s gonna stop. Shouldn’t be the reason for your wild groups. Probably your GB touching your handguard.

[No Bananas]

Yes, it could be eye sight. I’m 41 and just this year, I’ve had to start using reading glasses. Need to get em checked.