.22lr conversion with 1/7 barrel?

[Bimmer]

Hi,

I'm considering getting a .22lr conversion to use in my 1/7 twist, mid-length, 14.5" upper.

I know that 1/7 is too fast for .22lr, but is there any way to make this acceptably accurate? "Acceptable" to me would be 4-6MOA, say 1 or 1.5 inch groups at 25yds. I'm more than willing to use just about any .22lr ammo.

No, I do not want a dedicated upper. I want an autoloading .22lr for $200 or less, and this seems like a good way to get it. If a .22lr conversion in my AR is a non-starter, then I'm shopping for a Ruger 10/22.

I searched, and there are a couple anecdotal mentions of this working or not working. If anybody has any experience with this, please post.

Ben

[at4rxj]

I used 1/7 because I got it cheap. It's only about 7", which probably negates some of the twist rate (maybe?).

It gives decent accuracy out to 25yds. I've never shot for groups, but it hits the target.

[MX5]

A dedicated upper is nice for sighting and cleaning purposes, but the slight variation can easily be compensated for by the shooter when using it as a drop-in on the host AR. Reliability is very good with quality .22LR ammo; Mini-Mags work very well. Clean your barrel accordingly and you shouldn't have any issues with build-up.

There are minor differences between the .22LR and .223/5.56 barrel inside diameter; about .002". From a practical standpoint it makes little to no difference for the intended use. The bullet will not bounce down the barrel as some people profess. The soft lead upsets enough to get sufficient accuracy. Mine group 1.5" - 2" at 50 yds. and in.

For the lowest possible cost, a drop-in on the host weapon is the way to go. The Atchisson type kits by Ceiner are hard to come by right now or command a premium - CMMG is releasing theirs any day now & appears to be essentially the same design.

[CarlosDJackal]

When using my Colt conversion kit in either of my 10.5-inch LWRC or 10.5-inch LMT 1/7-twist uppers, I have found that the accuracy is more than acceptible plus I do not have to change my RDS settings because they have the same POI at 25-yards and close as with the .223 rounds.

[MX5]

If cost is a factor, sometimes you can find an older AR15/M16 bbl in 1/14 or 1/12 twist that is left over from someone upgrading to 1/9 or 1/7 twist. The 1/14 & 1/12 make very good shooters for the .22 conversions when building a dedicated upper.

[45r]

I have a Cienier kit that I use with my N4. The barrel is 1/7 twist and at 25 yards it pretty much shoots about 3 inch groups using cheap Federal Bulk Ammo.

[Bimmer]

Next question: Has anybody actually laid hands on a CMMG kit yet? I want to see some reviews of these before I plunk down my money...

Ben

[lindertw]

I've got an order in with Brownells for the CMMG kit - they say it'll be available to ship ~20 OCT.

I plan to run it through a Colt 6520 barrel (16" 1/7 twist).

[austinN4]

I have a Cienier kit that I use with my N4. The barrel is 1/7 twist and at 25 yards it pretty much shoots about 3 inch groups using cheap Federal Bulk Ammo.

I wonder about lead fouling with the 22 conversion. What is your experience? Thanks!

[CarlosDJackal]

I've got an order in with Brownells for the CMMG kit - they say it'll be available to ship ~20 OCT.

I plan to run it through a Colt 6520 barrel (16" 1/7 twist).

This is what i was told by Brownell's as well. I'll post my thoughts once I get it (I already have 2 BDM magazines for it too ).