Shooting the AR15 22LR Conversion Kits

[TD1886]

Out of 3 browsers Chrome, Firefox, and Edge only Edge would open it. Very informative website.

[TD1886]

Ad that article talked about, did you ever manage to plug up anything in the gas system of the AR shooting those soft 22lr lead bullets? I never have. Here's another one for you the gas system. While in Nam did you ever see a plugged gas tube or carrier key?

[Larry Gibson]

No, never had nor saw any blockage in key or gas port in Viet Nam or in the years since.

Have not experienced any such with the use of the M261 device either. The manual says firing standard M193 will blow out any build up if there is any.

[TD1886]

No, never had nor saw any blockage in key or gas port in Viet Nam or in the years since.

Have not experienced any such with the use of the M261 device either. The manual says firing standard M193 will blow out any build up if there is any.

Good info Larry

[barnetmill]

Here's something y'all may or may not know. There is a device called a Bore Buddy that pushes your conversion unit deeper in the chamber of your rifle and takes the fore and aft play out of and supposedly making it more accurate. I haven't tried that, but if I get another conversion unit I'll make one and see if there is a difference. Here's the link and scroll down to 22LR AR Buffer pressure plug:

https://borebuddy.com/

Thanks for the information and I see it will work with my CMMG conversion kit. I am pleased my conversion kit. I never have had any expectation of accuracy other than hitting steel swingers at 100 ft. I use it for with an AR pistol that only has the currently legal bare buffer tube and the brace removed and disposed off. At the end of each session I fire a round of 5.56 through it to clean out the gas tube.

$52.50 – $61.50

Swap the collar on your bolt for this chamber adapter to shoot 22lr through any standard 223/556 AR. The chamber adapter is compatible with BoreBuddy/CMMG/RTB/Palmetto 22lr bolt groups.

[TD1886]

Thanks for the information and I see it will work with my CMMG conversion kit. I am pleased my conversion kit. I never have had any expectation of accuracy other than hitting steel swingers at 100 ft. I use it for with an AR pistol that only has the currently legal bare buffer tube and the brace removed and disposed off. At the end of each session I fire a round of 5.56 through it to clean out the gas tube.

$52.50 – $61.50

Swap the collar on your bolt for this chamber adapter to shoot 22lr through any standard 223/556 AR. The chamber adapter is compatible with BoreBuddy/CMMG/RTB/Palmetto 22lr bolt groups.

For what that buffer is you could make your own out of some form of plastic/nylon as it's just a spacer not a reciprocating buffer like the original when the rifle is put back into the 5.56x45 use.

[TD1886]

The M261 is better designed and made than all of the commercial devices I've so far seen, including the CMMG device as shown in that site's video's. All of the problems [chamber part needing pushed forward, sloppiness of fit and gas blow back through the charger handle slot] are already addressed and are non-problems with the M261.

I would point out that at the closer ranges the use of 22LR devices in faster twist ARs the accuracy is certainly acceptable for the type of shooting demonstrated in that site's videos. However, the level of accuracy needed for 50' alternate qualification courses is just not there with 7" twist barrels as it is with 12" twist barrels. Nor did I find the accuracy to be there for small game/vermin at 50 yards as it is with the 12" twist ARs.

I've recently noticed a similarity between the M261 and the early Colt device. That's the small flat spring at the rear of the device. That puts pressure on the unit and that is why the CMMG is sloppy because they elected to eliminate that part. CMMG makes a lot of really good things. Their Raidial Delayed Blowback bolt system is very innovative. They may have cut corners on the 22LR conversions to cut cost. When I had my Colt one I never got gas anywhere.

[barnetmill]

I've recently noticed a similarity between the M261 and the early Colt device. That's the small flat spring at the rear of the device. That puts pressure on the unit and that is why the CMMG is sloppy because they elected to eliminate that part. CMMG makes a lot of really good things. Their Raidial Delayed Blowback bolt system is very innovative. They may have cut corners on the 22LR conversions to cut cost. When I had my Colt one I never got gas anywhere.

Loose and sloppy might have other advantages relative to function or might not. But few will be used beyond plinking ranges and for me for combat training it is fine.
I would like to have a unit that would work in 300 black out or 7.62x39 uppers. The chamber would have to be extended in the 30 cal bore and be rifled.

[TD1886]

Loose and sloppy might have other advantages relative to function or might not. But few will be used beyond plinking ranges and for me for combat training it is fine.
I would like to have a unit that would work in 300 black out or 7.62x39 uppers. The chamber would have to be extended in the 30 cal bore and be rifled.

Kind of sounds like a smaller caliber device which is a steen chamber insert. Example: 32acp from a 30-06 insert. I have a 35 Whelen insert that shoot 9mm Luger. You wouldn't have to swap out your bolt, just insert the steel cartridge with the sub caliber round it. I think they your rifle becomes a single shot.

[barnetmill]

Kind of sounds like a smaller caliber device which is a steen chamber insert. Example: 32acp from a 30-06 insert. I have a 35 Whelen insert that shoot 9mm Luger. You wouldn't have to swap out your bolt, just insert the steel cartridge with the sub caliber round it. I think they your rifle becomes a single shot.

A single shot is not much good for combat training is the problem. But one can shoot for example 9mm in .410. So why not a cmmg chamber insert with rifling to allow use of .22 in a 300 bore rifle. Perhaps the rifled extension would not have enough wall thickness to be useful.

[Larry Gibson]

https://www.youtube.com/watch?v=oXVXON95buM

Here's an accuracy test of various ammo with the CMMG Bravo device in a Ruger AR with an 8" twist custom barrel.

[Moleman-]

Interesting shooting results. At 50yds out of the 1:14" barrel it's easy to hit cans. May have to take it to the range next time and actually shoot on paper. No issues with the gas system either. I used to only run a chamber brush and bore brush through the barrel before switching to 223 if I've shot more than a box. One time I made the switch with it pretty dirty and the first round fired but stuck in the chamber. The rim was ripped off and the extractor pin bent. I keep a cleaning kit in the truck and have a spare extractor with spring and pin in my range box. Knocked the case out, replaced the extractor and pin, gave it a quick cleaning and it ran trouble free in 223 like normal. Just a fluke? Don't know but I make sure to run the chamber and bore brush though it every time now when switching back to 223.

[TD1886]

https://www.youtube.com/watch?v=oXVXON95buM

Here's an accuracy test of various ammo with the CMMG Bravo device in a Ruger AR with an 8" twist custom barrel.

I watched that. Here's what I got from it. When he was using the device with 22LR it shot the best with those 36 gr hollow points. If I had all the bullets he shot and could compare the bullet length, not the OAL, be interesting if seeing that the 36 gr bullet is shorter or not. If so, according to twist theorist, the shorter bullet should have shot the worse because of the too much twist for it. I didn't count the Stinger round becasue it's altogether a whole different thing then the standard Long Rifles and the velocity is much higher. I have had Stingers shoot exceptionally accurate in regular 22 LR rifles and pistol/revolvers. I'd have to say the CMMG device shot crappy. Looking at it out of the rifle is certainly looks very well made. I'm going to have either an older Colt device or a M261 device coming soon so I'll do a thurough test.

[Larry Gibson]

I was mildly surprised by the MiniMag group he got. That is until he said at the end, he said he had the custom 8" twist barrel on the Ruger AR. That made a bit more sense as his MiniMag group closely resembles the same size of groups my 9" twist Colt HBar with most HV 36 gr copper plated 22LRs that have been "Waltzed". The Colt's 50 yard 10 shot groups usually run 2"+ with a couple filers. The RPM using most "HV" 36 gr HPs with 8 and 9" twist barrels will run 100,000 to 113,000+/-.

I've got some MiniMag stashed away with other 22LR loads including some Rem Yellow Jacket, Stingers and some subsonic. If the weather cools a bit I'll also get out and run a test through my 12" twist milsurp barreled AR.

[TD1886]

I was mildly surprised by the MiniMag group he got. That is until he said at the end, he said he had the custom 8" twist barrel on the Ruger AR. That made a bit more sense as his MiniMag group closely resembles the same size of groups my 9" twist Colt HBar with most HV 36 gr copper plated 22LRs that have been "Waltzed". The Colt's 50 yard 10 shot groups usually run 2"+ with a couple filers. The RPM using most "HV" 36 gr HPs with 8 and 9" twist barrels will run 100,000 to 113,000+/-.

I've got some MiniMag stashed away with other 22LR loads including some Rem Yellow Jacket, Stingers and some subsonic. If the weather cools a bit I'll also get out and run a test through my 12" twist milsurp barreled AR.

When I get those devices I'll do a test. This will be with my old HBAR. I'm worried the gas port hole is large and might tear up those soft 22lr's. I have a 16 inch barrel carbine that's new. Might try it also and it's a 7 twist too. I want to get to the bottom of is it the twist or the over sized 5.56 barrel for the 22LR.

[TD1886]

So what could a custom barrel entail? It's still more then likely going to be a .224 bore and still be a 7 twist. Probably not chromed lined too.

[Larry Gibson]

Noting almost [at least I've not found any other twists] all dedicated AR 22LR uppers and replacement barrels have 14 or 16" twists. Hard to find any groove specifications for those barrels but I'm assuming they are the standard .222/.223 of regular 22LR barrels. You may have something on the barrel groove diameter affecting accuracy but the bullets in the video targets all went through point first demonstrating the bullets were sufficiently stabilized.

My previous testing Back in the early 'mid/late 80s using multiple military M16As (12" twist), M16A2s (7" twists) and commercial AR HBars (9" twist) showed definitely the 12" twists always gave better accuracy. That's why back in '06 when I found a new military contract refinished M16 upper with a new milpsec made M16A1 barrel I bought it immediately and built my AR "shooter" for use with M193 and Speer 52 gr HP reloads along with the usefulness of the M261 device.

The shooter in the video states at the end of the video that the Ruger barrel is a 16" factory barrel with an 8" twist. I must not have had my "ears" in when I first watched it and "heard" custom and assumed it was as I didn't know Ruger was useing 8" twist barrels as they are mostly used for competition rifles. Not on 16" M4 wanna be's. He also wonders if the inaccuracy, particularly with the higher velocity loads, has something to do with the fast twist. He's right, it does.

[rockrat]

IIRC, H&K had a 22 cal. conversion kit for their HK91/G3 rifles that had a barrel that fit down the 30 cal. bore. I just use a dedicated 22lr upper I got years ago.

[M-Tecs]

I understand why the AR15 22LR Conversion Kits came about for military usage and early AR 15 civilian usage. In the 80's and early 90's I had to qualify with them. I didn't care for them then and I still don't care for them now.

I did liberate 3 AF M-261's when the AF discontinued usage. I have mine paired with 3 retro builds I did but I rarely shoot they. I do have several dedicated 22 LR uppers that I love. I built a couple of Krieger barreled dedicated 22LR uppers that will give the best match rifles a run for their money.

What I don't understand is why folks spend $169 or more on a conversion kit when you can purchase a dedicated 22 LR upper for around $50 more?

https://www.bearcreekarsenal.com/22-...l-branded.html

[TD1886]

I understand why the AR15 22LR Conversion Kits came about for military usage and early AR 15 civilian usage. In the 80's and early 90's I had to qualify with them. I didn't care for them then and I still don't care for them now.

I did liberate 3 AF M-261's when the AF discontinued usage. I have mine paired with 3 retro builds I did but I rarely shoot they. I do have several dedicated 22 LR uppers that I love. I built a couple of Krieger barreled dedicated 22LR uppers that will give the best match rifles for the money.

What I don't understand is why folks spend $169 or more on a conversion kit when you can purchase a dedicated 22 LR upper for around $50 more?

https://www.bearcreekarsenal.com/22-...l-branded.html

When I bought my one and only first Colt unit I don't believe there were any dedicated uppers being made. It was just the idea of a novelty I believe.

Just recently I build a dedicated 22 Magnum upper. I've always felt and believe 22 mags weren't as accurate as 22LR rifles because the manufactured wouldn't do all the tricks to improve their accuracy. One which is a more match type chamber. So my match heavy barrel (Green Mountain 22 Mag barrel specifically made for the 22 Mag) AR15 with a special reamer I got made shoots very very small one hole groups at 100 yards. Then after I bought a Howa 22 Mag rifle, bolt action, and to my surprise it does the same thing. After that I bought an old Winchester 22 LR bolt rifle, one of the very few that Winchester made with a two front locking lug bolt with control feed. Forget the model number off the top of my head. I pulled the barrel and used my special 22 Mag reamer and put it back together as a single shot. Scoped it and with the stock trigger, standard 22LR barrel, and a 22LR bore and groove the .224 22 Mag bullet shot very well indeed. Not like the other two for sure, but let's say 1/2 inch at 100 yards. A lot of times I do things just to do them if you're wondering.