I have a few questions for you guys about the M-261 and Air Force conversion kits.

Will the M-261 magazine (insert) work with the Air Force conversion?
Other than the auto bolt lock are there any differences between the two?
Which of the two kits is the most reliable?
Are there any other kits that will use the M-261 magazine?

Thanks for any help.
-Jason

The magazines that come with the units are not interchangeable and the M261 will not work with any other conversion unit. Other than operating with 22lr ammo the physical design differences between the M261 unit and the Air Force unit are considerable and you can't swap/mix parts. I have both of them and I prefer the Air Force unit over the M261 because of the bolt hold open feature and the mags work better for me. I do have problems with the M261 insert magazines not working well in some rifles. They both will have about the same accuracy. Compass Lake engineering likes the M261 for their custom 22lr uppers (Big Bucks) but I believe they do some mods to the unit to make them function better. This is just my experiences with these two units. Is there a reason you would not want to try a Ciener unit? The Cieners are still in production and, except for the 30 round mags, parts are easy to get!

Can either of the USGI kits be made to work on full auto?

Thanks for the help AR-fan.

I really don’t want the Ciener.  I got one of his Glock .22 conversions when they first came out, and it’s the biggest piece of JUNK I ever wasted money on.

The M261 is built like a brick outhouse. The only problem I ever had was the mags, although some people have had problems with other parts. If the M261's the unit you want to stick with and you need parts you can go to SARCO. They even sell the complete unit. I don't know if it comes with a mag or not.
The Air Force unit may be a little more of a problem if you need parts. seems the Air Force units have just plain vanished. You can find mags now and then. The last time I saw some was in "SubGuns" for $25 each. They were the newer White plastic mags.
Some people have great luck with either of these units right from the start and others have to play with them for a while.
Good luck with what ever you decide on.

I have the Air Force conversion unit, since that is the one I used in the service, I wanted it.
It has worked flawlessly, several thousand rounds and full power ss109 in between. I have never had a jam, knock on wood.
Mine is the type with the white plastic mags that look like a 30 rounder, but hold 10 rounds of 22lr.
I have even taught my youngsters with this weapon and used Aguila 22 Colibri rounds, fed one at a time. It wont cycle the action with these, but makes almost no sound and shoots them great. I use Remington gold hps with this setup, and it eats them great. Nice groups at 25 yards.
My weapon is a preban Essential Arms shorty with collapsible stock, 11.5 barrel and long flash hider.
I have never used the M261, but around here, I have had no trouble finding mags for my Air Force unit. I bought 2 at a gun show for $25 and I still see the same guy with them about 3 x's a year at local shows, and he always has them.
Good Luck
P.S. I had one of the first Ceiner conversions for Glocks in my area, and I got lucky with it too, because I very rarely had a problem with it. Maybe 2 jams in 3,000 rounds. I attributed these to Aguila 22lr ammo that shot very dirty. I don't shoot that type anymore.

Remember, a weapon that jams is nothing but a very expensive club.

The M-261 gets my vote. We evaluated several conversions before we started developing the AR22 at Compass Lake. The Airforce has the hold open, but we determined that wasn't necessary in a non-combat weapon. For rapid practice, load 3 and 7 and do a hot mag change after the first two.
The Colt was too complicated at the bolt face having two guide rods. The Ciener, well I won't even go there.
We were fully prepared to design and build a system, but the M-261 met so many of the points on our wish list that we decided to go with it after some experimentation.
I have heard that the army had 195,000 of these made so I doubt the supply will dry up anytime soon. The M-261 works as well as any conversion and has the added benifit of being 'mil-spec'. If you go with the M-261 and later decide you want a dedicated upper, you won't have to buy it again as you would with an other conversion.
Regards, Ray