[img]http://noreno.no-ip.com:800/guns_big.png[/img]
First note. From what I can tell, these should not cycle. They should require manual cycling.
The one in the 1st picture would be an AOW, the 2nd an SBR. The 3rd (with permanent installation of muzzle attachment) should be a rifle and the 4th should be a pistol since it lacks a stock.
Notes:
The Barrel Extension would come from an AR-10 or .30 Caliber AR-15.
The Bolt Carrier would be a modified AR-10 or .30 Caliber AR-15 Bolt Carrier. The Bolt would be unmodified.
It would use a double spring design with one spring inside the upper part of the bolt carrier and another in the rear section. Simply pushing rearward against the rear spring would not allow the bolt to open enough to eject or feed a round. The Charging Handle would have to be turned about 90 degrees against a spring to unlock the 2nd spring allowing it to go far enough back to feed or eject a round.
Since it is a bolt action, I don't think the fire controls would need to be capable of preventing slam fire. I'm not sure though if the ATF would be happy if I modified the bolt carrier to prevent slam fire should the bolt follow.
I'll have to draw up a set and send them to them ATF Tech Branch for their opinion.
I would like to make #3 (Rifle) and #4 (Pistol) for myself. Since they aren't Semi-Automatic, I should be able to have any evil features I want as illustrated.