At the end of this summer I bought a couple of Kuehl 20" .22lr barrels.  I had Eric at Lakeside Machine cut the barrels down and reprofile them.  Because Eric was so busy with the LM-7 it took almost four months to get the work done.  While I was waiting I looked for Ciener kits to use in the new uppers.  I traded some mags for what I thought was just another Ciener kit.  When the kit arrived, there was a 30rd mag and adapter in a box like the other kits I have.  The instruction book was different but at the time I just put the kit with the others I had bought for this project.

This weekend I put the two uppers together.  I cleaned the kits and mags, removed the shell sleeve adapters and ground the rails on two of the kits, so the kits would fit the Kuehl barrels.  When I started cleaning the kit with the different instructions I noticed that the mag and adapter were blued instead of parkerized.  The adapter had roll marked on the top of the rear part of the rails:
               "ATCHISSON M16 / AR15
                 .22    L.R. CONV.  MK.  II
                     W.  A.  K.  INC
                 DATON, OHIO U.S.A
                    PATENT PEND.
With a hand stamped serial # below that.    The right side of the flat adapter plate that locates the mag in the magwell has the same roll mark.

   The only difference I can see between this unit and the other Ciener units I can see besides the blued finish is the firing pin.  The Ciener units have a round end where the hammer would hit.  This unit has a flat plate about 1/16" thickness, about 3/8" wide and about 1/16" longer than the unit.  The firing pin has no spring to push the firing pin like the Ciener unit.

   Does anyone know anything about this unit?  I really don't want to grind up the rails and ruin the kit, if the kit has any collector value.  If there is some collector value, how much would it be?  I understand that the Ciener firing pins are a weak spot.  If the unit has no collector value where could I get parts.  The kit has been used but looks in very good condition.  It has the anti bounce weight and sear trip just like the Ciener kit, original instructions, 30rd mag, and case.  Any information would be appreciated.

Scott

I have 1 I foun at garage sale back somewhee around 87?   Paid next ot nothing for it.

I dont use it, needs springs, weak.

The fire pin is as you describe, and if anything breaks, Ciener parts would be used to repair/update.

Here is mine, the adapter was mis-placed at the time, fella wanted to know how it went together.

This is the same unit that JAC is now producing.  As you have noted, the only difference is the firing pin.  I don't know where you would get a replacement for the old style, but since it's just a flat piece of steel it wouldn't be hard to fabricate one.  I don't think they have any collector's value so take it out and shoot it.

To keep from having to file the nubs off the end to fit a Kuehl barrel, I bought a replacement guide plate.  I can now use it with the chamber adapter or without.

This is the same unit that JAC is now producing.  ...

I believe the JAC unit is called a "Mark III" Atchisson but other than the firing pin I don't know what's different.  

To keep from having to file the nubs off the end to fit a Kuehl barrel, I bought a replacement guide plate.  I can now use it with the chamber adapter or without.

I filed the nubs off mine for the Kuehl barrel and it still works fine with the adapter too.  A tiny bit harder to insert, but if you put the adapter on the rails and keep it level it's not that hard.

A tiny bit harder to insert, but if you put the adapter on the rails and keep it level it's not that hard.

Not if you're as thumb-fingered as I am!