Building an AR-22

[Caster]

SO there's a pile of extra parts I have accumulated in my shop, including an upper receiver with hairline crack at the rear that I don't want to use for centerfire. So, I'll build a dedicated 22LR. I've never even seen a dedicated AR in 22LR. What's different? I see the CMMG barrels and BCG's at Midway. Looks good. How's it work? Do you need the AR spring and buffer?

Admittedly, I don't even own a .22 rifle anymore. Haven't for a while. I am custodian of my mother-in-law's Henry, but none for me. Looks like a good opportunity to remedy that.

[mikegideon]

Here's Capbyrd's build. He's one of the biggest .22 geeks I know.

http://www.tngunowners.com/forums/long-guns/57550-dedicated-22-ar-platforms.html

[Dolomite_supafly]

It goes together just like a regular AR. The only thing it does not use the the buffer and recoil spring. I recently put one together using a CMMG barrel and Ciener conversion. With a dedicated barrel you need the barrel collar that replaces the chamber insert on the conversion bolt.

I have been using a 22lr AR for training since 2005. Back then I used a Ciener with the chamber insert. That conversion kit had 15K-20K rounds through it before I built a dedicated gun. The dedicated gun was built about a year ago and has to have at least 10K on it now.

The only magazines to use with the conversion are the Black Dog magazines. If you do not use the CMMG Evolution kit that has its own bolt hold open setup you need to get the bolt hold open followers for the Black Dog Magazines.

5 Pack Bolt Hold Open Followers

What they do is keep the bolt form dropping on an empty chamber. The reason why this is so important is the firing pins are a bit fragile on these and dryfiring can cause the firing pin to break. I had several broken firing pins before using these followers and none since. When you remove the magazine the bolt drops but it prevents you from accidnetally dryfiring the gun.

A lot of people talked about having problems from the dirty rimfire. But that was with the cahmber insret conversions because the gas tube was still intact. This dumped additional crud into the receiver. Since I went to a dedicated I can easily fire 1,500-2,000 rounds between cleanings if I am not using my suppressor. With my suppressor I get about 500-1,000 between cleanings. As far as cleanings go you need to remove the firing pin on a regular basis to clean it out. I would say every 5,000 rounds or so because it does get caked with crud enough to cause misfires.

One more thing, you might see recomendations of polishing the kit to make them more reliable. I did not do it to my most recent kit and it has been 100% reliable. About the only thing I might do is round the bottom rear of the bolt if you plan on shooting subsonics a lot. Not really sure if it is needed but if you are having issues cycling subsonics this does help. I also do not oil my kit and that seems to help keep it running longer. If I do start having issues and can't clean I normally use WD-40 or my home concoction as a stop gap to keep shooting. My home concoction is 33% ATF + 33% 30 weight synthetic + 33% fuel injector treatment. I mix it in a syringe and use it as needed. One could also mix a quart of ATF and oil then add the treatment. This has some slickness to it and also has a very strong cleaning action.

They are not any harder to assemble than a regular AR but they are a whole lot more fun. I shoot my 22 AR 100x more often than my 5.56 AR and with the right ammo they are very accurate. And with a suppressor they are extremely quiet platforms with the exception of the hammer noise .

If you have any questions feel free to shoot me a PM and I'll give you my number so you can call me.

Dolomite

[Capbyrd]

Sorry. Didn't see this thread till now.

Here is a pic of my dedicated. Parts list after the pic.

Surplus Ammo & Arms Lower

Palmetto State Armory LPK

Bill Springfield trigger job

Magpul MIAD grip in OD

Magpul PRS in OD

Brownells A2 stock kit (buffer, extension and spring)

Magpul Enhanced Trigger guard

Burris PEPR scope mount

Vortex Diamondback Rimfire 2-7x35

Defense Package Ambi Safety selector

Rifle Length Magpul MOE handguard in OD

Harris bipod on a knights armament adapter

Magpul BAD lever

Model 1 Tactical Charging Handle Latch

Now for the upper. The upper receiver is one of the complete CMMG uppers. I bought the 18 inch upper with the railed gas block because I wanted a long rifle and I knew I was going to run a scope. I opted for all of the upgrades. I got the stainless collar, stainless bolt, bolt hold open option and forward assist. I also opted for the mil spec annodized receiver.

Overall I've been very very pleased with the rifle. It hasn't been flawless though. The bolt hold open is a little bit of a pain because it can interfere with feeding if not fitted properly. Either spend the time to fit it or leave it out though and it works well.

I also had some light strikes at first but I found those to go away once the BHOA was fitted properly as well.

Overall, its been a ton of fun to shoot and it looks mean. Mine seems to like Federal Automatch but I also run subsonics through it when the Mite is screwed onto it.