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“Best” FA capable 22 LR AR/M-16 upper?

superde

Gunny Sergeant
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Minuteman
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Nov 7, 2003
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Bryan, Texas
Off topic for this website, but I figure there is someone with the knowledge I need here.

I built a Cenier upper probably 15 years ago, but couldn’t get it to run more than a few mags without taking it apart to clean and lubricate. Surely in that time something better has been released?
 
Off topic for this website, but I figure there is someone with the knowledge I need here.

I built a Cenier upper probably 15 years ago, but couldn’t get it to run more than a few mags without taking it apart to clean and lubricate. Surely in that time something better has been released?
It's the nature of 22LR ammo. Bullets are waxy and the primer creates a silica like residue. Combine the two and you get what you got.
 
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I'll second CMMG. I had a dedicated .22lr upper with their barrel, collar, and bolt and eventually added their FA trip when it became available.

Others have had issues with timing the sear trip to work in FA, but mine has run great since day one without modifications on my RR M16.

ETA: forgot to add that I'm using their anti-bounce bolt weight as well. I've never had an issue with OOB or hammer follow in FA.
 
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I’ve had great luck with dedicated .22 uppers built from CMMG parts on an M16 lower. I have 4.5” and 9” uppers that both rock and roll very well with the CMMG auto trip and bolt weight kit. With cheapo waxy bulk pack ammo and a suppressor , I can get around 3-400 rounds before it becomes a jam-o-matic and needs a good cleaning.

In the 4.5” barrel, the bulk ammo will stay subsonic…. Full auto suppressed subsonic .22 is an absolute riot. I do think the bolt weight add on is key to getting it running well… it slows the cyclic rate a bit.

Borebuddy and probably some other shops make “pressure plugs” that fit in the buffer tube ahead of the standard AR recoil spring/weight and put pressure on the .22 bolt group, I think these help as well with reliability. Totally worth the $10 or whatever.

They also make dedicated .22 charging handles and inserts for standard AR charging handles that are worth getting… spent .22 brass can get caught in the bottom of a standard charging handle and cause annoying jams.

One of the local FFL SOTs I know likes .22 parts and especially adjustable bolt weight kits from bore buddy. I bought the bore buddy parts but honestly my CMMG stuff has run well enough, I never even tried it. Still, might be worth a shot if you can’t get CMMG to run with your lower.


(I am in no way affiliated with bore buddy)
 
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There are some limitations for the fire control group due to the shape of the bolt. Manual is on the website withe schematics and everything.


Reports about bore buddy seem very good. They even have a non metallic collar they sell that makes the system even quieter if you are suppressed




Rimfire specific 00 grease available now was well

 
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