AR with a .22lr convertion

[sarduy]

hello guys...

i'm planning on getting another CMMG 5.56 upper 16'' (mid-lengh) with a 1:7 twist, but i also going to install a .22lr convertion kit (i dont want a 22lr only upper) so i have this question, what kind of accuracy i can expect from a 16'' 1:7 twist upper shooting 22lr ar 50 100 yards? will the bullet be accurate or they will get all over the place? i think the twist is way too fast compared to my savage mark II with a 1:16.

Edit: i also need to know what about barrel life? will that wear out the barrel?

 

[Zach S]

I've only shot my CMMG 1:7 out to 25 yards with the conversion. It patterned instead of grouped (2 to 2.5"). My RRA 1:9 did much better (around 1.5").

I'm much happier with the accruacy of my rimfire AR. The one time I shot at paper I did my part and got a .5" group at 25 yards. Most of the time I use it to defend attacking cans and rotten fruit...

 

[Shung]

I am not sure that the 1/7 twist is ideal for the 22lr..

even if you dont want to, im pretty sure you'd be much happier with a 22lr upper with adequate barrel...

I've gone through this myself these days, and I finished my 22lr upper yesterday :


the twist is 1/16 i think, barrel being close to 16"

here is what I get for a group at 50m.



The only thing Im pissed at is that I cannot find a lower only for it. I have to swap from my M4 clone.. I whish I could by a lower only as easely as in the US... but here nobody sells stripped AR's...

go for a dedicated 22lr upper, you won't regret it.

 

[mainmech48]

Most folks seem to get patterns rather than groups from RF conversion kits. The barrel specs for 5.56 are all wrong for .22 RF, both in twist rate and diameter. There have also been reports of "spontaneous disassemblies" happening if the barrel wasn't meticulously scrubbed free of lead and powder fouling before switching back to CF ammo.

IMO, a dedicated .22 RF upper would be a better choice all around.

 

[sarduy]

i guess i'll be better of getting a .22 upper

 

[taliv]

1" at 50 yrds is doable regularly with decent ammo (i.e. not remington)

 

[stiletto raggio]

If you really want a conversi0on kit rather than a dedicated upper, I recommend trying the heavy Aguila 60 grain Sub Soni Sniper rounds. They are a bit more expensive, but the extra length and weight of the bullet should stabilize better than a 40 grain or lighter bullet. It should be pretty darn quiet, too.

 

[Zach S]

Another option to consider is getting a surplus 1:12 bbl (or bbled upper - if you can live without a flat top). It wont be as accruate as a dedicated upper, but it will be much better than a 1:7.

If you already have a conversion, you can use a KKF rimfire bbl. It has the correct .22 caliber bore and 1:16 twist, but has a .223 chamber so you can use whatever conversion you wish. The only downside is the price of the bbl, mine was a little over $300 shipped, but I had him make a dissipator style bbl (his first dissy, actually).

Considering the price of the bbl, conversion, and upper, it cost me a little more than Spike's or M1S, but on the other hand, I can take the conversion out of my rifle and put it in another. Comes in handy for getting new builds and purchases on paper at the indoor range, or getting a little trigger time with my go-to 5.56 carbine, that has developed an expensive diet in the past few years...

If you dont want to invest in a dedicated upper at the moment, or just dont have the money for one (which was my problem), you can still get a 1:7 twist upper and use the conversion it it for the time being, however it just wont be that accurate. Then buy your .22 upper in peices. M1S will modify your Ceiner conversion for use with their bbls (or use a KKF bbl with your un-modified ciener), then get an upper and charging handle and put it together.