.22 conversions for the AR.

[thunderbolt]

I've been looking at getting a .22 kit as well and was wondering if the barrel twist rates of an AR (mine is 1:8) vs a dedicated upper (1:16) affect performance or does it matter that much?

[till44]

Don't expect great accuracy from a conversion kit in a standar 1:7-9 AR barrel. The bullet gets spun too fast and accuracy past 30-35 yards suffers.

I have had a CMMG kit for a little more than 2 years with no real problems shooting all kinds of .22 ammo. Copper jacketed rounds are by far the cleanest. I have had a few stovepipes when shooting lead nosed ammo, but even then it is rare, maybe 1 every 150 rounds. But then they tend to do the same thing to my Marlin 60 and 10/22 as well so I blame the ammo.

CMMG is supposed to be releasing a new drop in bolt catch that should be handy to have as well. www.youtube.com/watch?v=4rLioM2_LJE

[uracan]

I purchased a dedicated upper from velocity firearms for sub $300 a few years back, I've been happy with it, it is a composite upper with a barrel that has a 1-16" twist that helps with accuracy. but being a 22lr upper I do get occasional issues with ammo, but It eats most 22lr without any problems. I would recommend it as an inexpensive 22lr upper.

[wrightb]

I bought the CMMG conversion kit for my son, he uses the bulk Federal .22lr with no issues. They say that .22 ammo puts a lot of junk in the gas tube but that firing just one .223 round cleans the tube out.

I have been wondering something, how often do you NEED to clean out the gas tube after firing 22? I have much more opportunity to shoot 22, very little to shoot 223. If I leave it in there for weeks to months at a time, will it eventually cause problems?

[Grumpyoldretiredcop]

I deliberately left mine alone for over 1000 rounds of .22LR. Installed the 5.56 bolt carrier group and it functioned perfectly. Based on that example, I suspect that a lot of what is said about gas tube clogging from .22LR use with conversion kits in 5.56 uppers is FUD.

[thunderbolt]

I've been having a real hard time trying to decide if the .22 conversion is worth it. At $160+ will it fill my needs for a reliable, fairly acurate plinker or should I save my money and get a dedicated upper. But at $400+ is the upper any more reliable? Then what about a seperate .22 like the S&W... Argh!!

[DCF]

I have a CMMG conversion kit and it runs perfectly after may be 500 rounds to break in. I had to take it apart, clean and lube the kit for it to run without a hiccup. Although I still get a few FTF if I use a 'bad' mag... Luckily I have 2 mags so I just use one of them exclusively.

Didn't expect a lot on accuracy. With winchester or federal bulk pack, I am satisfy if I can keep all the rounds within a 2"X2" square at 25 yards with a 1:7 barrel. I did try lots of different brands of 22LR and none give me any significantly better results compare to the bulk packs. At 3.2 to 3.6 cents a rounds, I can shoot it all day long and keeps both me and my bank account happy.

[brassburnz]

I have the old military M261 conversion kit I run in an Olympic Arms upper with a 1/10 twist. It works great and the accuracy isn't too bad but not as good as my Umarex/Colt M4 .22 rimfire. The only issue is the fact it uses a magazine insert, so I have to use-up an otherwise perfectly good AR magazine for the conversion.

I'm seriously thinking about getting the CMMG dedicated upper because it has the proper twist for a .22 rimfire and it uses BDM magazines which I purchased in anticipation of picking up a Spikes .22 conversion but the deal was never made (but that's another story).