.22LR conversion in an AR

[Avanarts]

OK, this has probably been discussed before, but I didn't want to go searching thru several years of posts, so please be kind.

I bought a CMMG .22 LR conversion for one of my AR's and was thinking that I would just leave it in and use that one as a dedicated .22 that could be switched back to 5.56. Then I got concerned that shooting a steady diet of .22's thru it might mess up the gas tube with a buildup of lead.

Is this a valid concern? Would there be a difference if I stuck with ammo with "copper plated" bullets like CCI Mini Mags rather than just shooting the cheapest lubed lead ammo?

[Schuetzenman]

Yes IMO it is a valid concern. But then again they do sell spare gas tubes. You could also remove the gas tube and just let it vent into the handguards. Cleaning out the front sight base / gas block shouldn't be that hard to do and most of what should be in there is the wax.

I would admit that I built my own dedicated .22 LR upper with a .22 LR barrel on a regular receiver, A3 type. So the .22 LR barrel has no gas port to let crud into anything. So really my advise is opinion vs. actually having experienced cleaning out a gas block.

[Avanarts]

Thanks.

[mars]

I thought about buying the kit for my AR15 as well but decided against it due to the twist rate of my barrel and the fact that I can buy an AR15 like 22 LR for close to the same price. If you are using high quality copper plated ammunition like CCI Mini-Mags I would not worry about the barrel.

[Helen Keller]

I put something like 4000 rounds through a .22 Ar conversion one winter and the only buildup was on the charging handle and in the suppressor.

ZERO crap in the gas block/tube area.

I used everything except plated rem. hollowpoints.





OF course this might be different with a different twist rate. Just due to the general filth I would just get a cheapo beater barreled upper to use if I did it again.

[Avanarts]

Thanks to everyone who replied. I got this CMMG conversion for a really good price from Primary Army a while back and, while I would prefer a dedicated upper, these days I just don't have the bucks.

It functions fine, but accuracy is nothing to brag about out of my 1 in 9 twist barrel. I don't plan on letting that bother me though since it will be used for short range (room clearing distance) practice.

[Schuetzenman]

Thanks to everyone who replied. I got this CMMG conversion for a really good price from Primary Army a while back and, while I would prefer a dedicated upper, these days I just don't have the bucks.

It functions fine, but accuracy is nothing to brag about out of my 1 in 9 twist barrel. I don't plan on letting that bother me though since it will be used for short range (room clearing distance) practice.

Frequently a lack of accuracy is reported on these drop in conversions. .22 Lr is .222 to .223 diameter bullets and .223 / 5.56 is .224" bullets. kind of a loose fit and the bullets jump a long way to get to the rifling. This allows for possible misalignment and that can result in bad acuracy.