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9/19/2017 7:27:10 PM
Posted: 9/8/2010 11:58:19 AM EDT
I'm looking to build my first dedicated .22 AR. Is it better to buy a conversion kit or a dedicated upper? I'd like to have an 8" barrel, for my SBR lower. My brother is giving me 10 Ciener 30rd mags so I need an upper or conversion that's compatible with the mags. I've heard bad things about the actual Ciener conversion kits. I have a friend that swears by the M1S .22 uppers. Any thoughts, comments, or suggestions would be greatly appreciated. Thanks guys.
Link Posted: 9/8/2010 12:41:24 PM EDT
I have a CMMG conversion kit and I like it. Obviously a dedicated upper is going to be hell of a lot more accurate. One thing with a conversion kit is it doesn't lock back on empty. Last I heard was there was something coming out that would allow this. Basically depends on what you will be using it for. If it's to train tactics with a duty weapon and you'd like to save ammo costs, get a conversion kit. If it's just to plink and you like the .22 rnds get a dedicated upper.
Link Posted: 9/8/2010 12:55:21 PM EDT
[Last Edit: 9/8/2010 12:56:57 PM EDT by Circuits]
The latest generation CMMG "Evolution" series .22 uppers and conversion kits promise to have a lot of neat improvements like functioning bolt holdopen, fwd assist, improved live round extraction, and all chromed or stainless parts to make cleaning easier and help them run more reliably. Nothing but the evo series has true bolt holdopen, although some mags have a "holdopen follower" which locks the bolt open at the back of the mag when empty (but drops the bolt when the mag is then removed).

A dedicated upper will have a proper 1/16 twist and .221 bore to make it a real potential tackdriver. Because the chamber is set back further on a dedicated upper, it can have a correct length M4 barrel (looks like a 14.5" .223 barrel from the outside) while still being a non-NFA legal 16" barrel length.

A conversion kit costs less to get into, still offers pretty good accuracy and the same amount of fun, but you need an old 1/12 bore to make best use of .22lr, while modern 1/7 or 1/9 are decent, but not spectacular. The oversize .224 bore and too-fast rifling twist, along with the jump from the chamber insert to the rifling contribute to reduced, but usually still quite acceptable, accuracy in the conversions as compared to a dedicated upper.

I currently run an older Atchisson/Ciener conversion, and intend to buy a CMMG evolution conversion kit when they become available.
Link Posted: 9/8/2010 12:59:08 PM EDT
CMMG's bolt latch activator is due to become available in the near future.
It should work with the kit or with the corresponding dedicated upper.

It appears to me that BDM's Gen III mags may activate the bolt catch without any additional hardware. Beta testing is occurring at present; see the thread. Same deal, conversion or dedicated upper.

The bolt and its relationship with the mags and bolt catch is the same whether kit or dedicated; it's the same bolt.

The benefit of the dedicated upper is that you never have to worry about your chamber being gummed up with rimfire fouling. And gas tube worries are non existent. Sight settings don't need changing, and accuracy is better.
Link Posted: 9/8/2010 1:18:33 PM EDT
[Last Edit: 9/8/2010 1:21:01 PM EDT by shadowcop]
As stated, better accuracy with the dedicated upper because of the 1/16 twist barrel. CMMG has the uppers starting at $350. No 8" barrel is avalable yet but you might call and ask if they can cut one for you.
The conversion is less expensive but every bit as reliable in my experience with them. I will always recommend the stainless. No break in, little lube, easy to clean. It just gets smoother.
I've been running the CMMG Quebec and just passed 3100 failure free rounds today using various .22 ammo. Mostly copper washed bulk packs.
Accuracy from the 16" blaster barrel has been 1/2"-3/4" at 25 yards. Eley of course shot the best.
I shot at 50 yards today and Eley came in at .820, Winchester 333 at 1.29, CCI Mini Mags at 1.20. Not bad for a stock barrel.
My 7.5" 1/8 barrel will shoot about 1" at 25 yards with the conversion.
I've used the conversion in all my 5.56 AR's from 7.5" to 16". Never a problem and never had to change, tweak or adjust anything.
Sights with the 5.56 and .22 are close enough for training at 50 yards. I never had to adjust them. Maybe 1.5"-2" difference.
The bolt hold open and forward assist should be available at the end of this month. The live round extraction is already standard, and it does work reliably.
Lots of field testing has been done with these. CMMG will not release them until they are proven reliable.
There are many upgrades coming for the CMMG Evolution System.
Dave
http://www.ar15.com/forums/topic.html?b=2&f=145&t=188909
Link Posted: 9/9/2010 4:08:03 AM EDT
[Last Edit: 9/9/2010 4:09:26 AM EDT by VaFish]
Originally Posted By KX4019:
I'm looking to build my first dedicated .22 AR. Is it better to buy a conversion kit or a dedicated upper? I'd like to have an 8" barrel, for my SBR lower. My brother is giving me 10 Ciener 30rd mags so I need an upper or conversion that's compatible with the mags. I've heard bad things about the actual Ciener conversion kits. I have a friend that swears by the M1S .22 uppers. Any thoughts, comments, or suggestions would be greatly appreciated. Thanks guys.


It really depends upon what you want.

A conversion kit give you cheap trigger time with your .223 AR. They won't give you the accuracy of a dedicated upper. Figure group size at least twice what the dedicated upper will give you. You also run the risk of clogging up the gas system on your upper.

Conversion kit is cheaper, but you said you wanted to build your first dedicated .22LR upper. If you are just going to leave the .22 conversion kit in a .223 upper and have it dedicated to .22LR only then you really should just buy a dedicated upper. Money will be about the same or even less for the dedicated upper, no gas system to clog up and better accuracy.

I have a Ciener conversion kit. It works pretty well. I think the problem is more Cieners customer service ( or lack there of) then problems with his kits. Most of the other kits are direct copies of the Ciener design (which is a copy of the original Atchinson)
Link Posted: 9/9/2010 4:31:43 AM EDT
Or if you want to build the upper yourself, CMMG offers barrel and dedicated BCG combo's by themselves.
Link Posted: 9/9/2010 5:23:25 AM EDT
I've been thinking about this a lot lately.

I'm going with the conversion kit - I already own an older Ceiner.
I've decided that to get an accurate .22lr for shooting small groups with a magnified optic it's better done with a real .22lr for a fraction of the cost. And if I wanted tight groups I'd buy better .22 ammo and that would negate the cost efficiency of the .22lr.
The conversion kit with irons and/or a RDS has plenty of accuracy for "minute of torso" grouping to train with IMO. It's fine for the moving and shooting drills I need to work on. But YMMV.

-JC
Link Posted: 9/9/2010 5:30:35 AM EDT
[Last Edit: 9/9/2010 5:33:57 AM EDT by shadowcop]
I talked with a guy yesterday that owns a conversion but never shoots it. He's overly concerned with lead in the gas tube.
I've shot several hundred rounds of .22 through my 5.56 uppers on numerous occasions.
When I'm finished shooting I run a Boresnake through the barrel while it's still warm, run 5 rounds of 5.56, and clean the rifle when I get home.
I've yet to have a problem, other than the residue that ends up in the receivers. I blow that out with carburettor cleaner and re lube.

And I agree. Accuracy is about 2" at 50 yards so it's plenty enough for training or hitting torso targets and plates.
I will say the CMMG is the only conversion unit I've used that has run reliably(very reliably) through all of my AR's from 7.5"-16".
I have the stainless version.
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