I'm puting together a dedicated pre 22 upper out of some spare parts that I have. Flattop upper, ciener kit, full length hogue gripper tube, 4 1/2" car FS, and a colt 20" 1-12  barrel.

I plan on cutting the barrel back to 12", re thread and mig the FS in a couple spots for a finished length of 16 1/2".

Will 12" of barrel be long enough (blow back)for the ciener to function properly?

Why no go with the Kuehl or Accuracy Speaks? At least the bullet will seal in the bore and offer a higher percentage of reliable function, intead of leak at adapter an all way down the bore, and accuracy will be a whole lot better.

I already have a fulton armory 22 m4 upper (christmas presant for my 8 yo daughter). Very nice btw, 1/2" 50 yds useing bulk cp federal, feeds flawlessly.

I'm only looking for tin can accuracy out to 50yds, besides I have all the parts to complete it.

These 22's are so dam much fun that I have to have my own when we go out shreading cans. [;)] You know the game....line up some cans, I'll take the left, you take the right, first person to the middle wins.

We just like to "grind'em up". Couple relatives get together  in yard down in WV and blast anything in sight. Fingers get tired after a while, but empties everywhere.

I have a Kuehl barrel that is about 7".  I've been tinkering with the damn thing for almost 2 years and now its finally running great.....but only with the silencer on for that added backpressure.
They are fun so I got a 16" regular 223 upper from a friend and it is running fine with an out of the box ciener kit.  I am thinking about cutting it down to around 12" also but am afraid to do so because of my past experiences.  I am planning on taking my 11.5" upper out this weekend and see if it runs on that.  I did this already a long time ago and it wouldn't run but I wanna try it again.
Below is a pic of my setup with Kuehl barrel and Gemtech Hornet suppressor.
[img]http://home.cfl.rr.com/c3stuff/ciener/22sd.jpg[/img]
BTW, you guys need to make a loader like I did.  Be warned, you will really burn through ammo then.  I load 30 round mags in under 30 seconds easy.

So, tell us about this loader...

I bought one from AD Hayes and it didn't work that good.  I think because mine was a little out of alignment.  I made my own that works awesome.  I used the same Ramline 10/22 loader then cut it up and modified it.  I made a couple for friends it is pretty easy to do.  You just need to shim it up properly.  The key is to have the mag elavated .40" from the base for the proper height.  I used .5" plexiglass and milled a .10" off where the mag rests and a .10" shoulder to keep the mag from shifting.
You do have to be familiar with a few quirks with the loader but once you are aware of them you can load really fast.  Loading 30 rounds in under 30 seconds is really a conservative guess.  I'm sure I'm loading faster than that.

Very nice amphibian!! I posed the same question over on Kurts site. He said 12" of barrel should not pose a problem. He has run them as short as 4 1/2" with the correct bore.

I will polish all bearing surfaces (rails, slot etc.)as a precaution. Trigger Slick is a very fine abrasive paste I've used for the final step on one of my S&W trigger jobs. Apply a thin coat and cycle the action. I believe Brownells carries it. Produces an incredibly smooth action.

Time to fire up the lathe. Will post some pics and a report when I get it finished.

I converted a ramline 10/22 loader to load the Ciener mags as well.  It works pretty good, but is not perfect.  I can load the 30 round mags in 20 to 30 sec.

It was not a simple task.  I have about 3 hours in it.  When I get home tonight, I will post a few pics.  It works so well, we fired 1100 rounds in 40 min with 3 mags.

[img]http://members.aol.com/cienermagloader/myhomepage/pic00013%20(2).jpg[/img]

Heres Ramline conversion from AD Hayes. $56.00

Finished upper today. Looks bitchen if I do say so. Cut barrel at 12 1/2" for a finished length of 16 1/2" with car attached. Got rid of gas port all together. Brought along a brick of federal HV CPHP's (walmart special) and 50 rounds of rem subsonic.

Conditions 28deg, gusty 20-30 mph wind. No CLP on bolt.

Ejection was almost identical compared to the 20" barrel. About 6' at 4 o'clock. Gun ran like a raped ape. No malfunctions in 550 rounds of federal.[:D] Even the subsonic worked fine, spent cases flew half as far as the HV.

Accuracy was better than expected. 23 of the 30 rounds clustered in about 2" at 50 yds with the rest being pushed around by the wind. Set up some cans at 100 and had little trouble tearing them up.

I actually like this upper better than the Fulton Armory. It was also a hell of a lot cheaper.