Seems like some are pretty quiet and don't touch much. Others I have nearly made a career out of tweaking them to no avail and the dang things sound like an outta tune banjo when I open the bolt. Does it matter as far as accuracy goes?

I don't know about accuracy but they seem to run smoother when everything lines up.

Absolutely they effect accuracy. The side pressure on the key plays hob with lock up stress. Not to mention premature wear on the tube that can make a difference in reliability.

Greg

On my new woa 22 Nosler with the extra-long gas system the tube spans such a long area without going through anything anymore snug then the hole in the front of the receiver between gravity and harmonics etc I don't think Im ever going keep it centered in the gas key. I need to look at my gas key and make sure it's straight but I can't imagine just slightly touching the gas key would really make any difference. If it was crank tight against it as the bolts closing I can see where that would probably upset things.

I guess we'll always wonder about that won't we? The AMU sure feels pretty strongly on the subject.

Greg

i always go out of my way to make sure that the gas tube isnt messing with anything. i want as little friction during cycling as possible.

if my bolt wont slide home with the lightest of touches, i go straight to the gas block for another minor bump to square things up.


anything else is to me as nasty as if your crosshairs are just a "tiny little bit" canted. ugh. lol

I took a new gas tube and slid it in my 22 Nosler gas key last night and it drags going in so I can't imagine how it would be possible to get zero contant when assembled.

You will always get some contact. But in this case, less is more. AR's are ALL about timing. ANYTHING that can knock the timing off can and will effect not only the operation of the gun but can have an effect on accuracy. Accuracy is being able to hit the target. Precision is being able to hit the same spot repeatedly. If anything is knocking off the harmonics of the gun, such as cycling inconsistencies, then the precision will be effected.

Would I spend hours trying to get it just right? No. Is it worth it to check the fit? Absolutely.

They call that tolerance stacking in many instances. Part of the issue is that if our tube comes from a different manufacturer or lot that while it may be in spec they can vary. Some seem huge and others not so much. The same with the gas keys.

Will it make a difference in coyote killing? Probably not once in a thousand shot. Will it make a difference in shooting a 0.05 group to carry in your billfold. Quite possibly but few of us are into that. I'll take my measly 0.3's any day I can get them.

Like Sno says it isn't worth hours of work but a few minutes tweaking is not something to not do just because.

Greg

Well I've got mine as close as any sane man is going to waste their life to get it ,and I've got about the cheapest gas tubes on the planet in my gun so I guess that explains it. When the bolt is closed you can wiggle the bolt around and basically it'll move under its own weight like there's no resistance so I think I'm good.

Sounds like that's one less worry. I hold no specif allegiance to gas tube manufacturers. I'll go to Brownells and just buy the cheapest that they have in stock. So far so good. I do avoid the melonited ones though as the extra step if done wrong can cause issue.

Greg