The first prototype for the gas system (the on on top in the image) used a simple tube receiver,but in order to work the bolt head cam pin and carrier guide(gas key) have to aline to block the head open so that the bolt can stip a round from the magazine (if the bolt head cam pin runs free it cams to lock the head as it tutches the cartrige and the bolt jams out of the lock chamber and the system fails) so for this the Ar-10 and AR-15 have a rail where the charging handle also moves,one other thing is that there is no space for the cam head to rest as it moves to the side when the bolt is locked,What was the way to make the bolt stip and operate in the prototype in order to work?


Thank you.

Looks like the top one used a BAR magazine.
Wonder if it was in 30-06?

30-06 with a BAR magazine,correct.

You might also notice the gas tube coming into the left side there.

The gas cut on the side was used in the AR-10 before the use of the gas key on top,in the image the carrier uses a carrier guide pice,it was used to aline it with the cam pin head and it also stoped the bolt assembky from rotating insidr thr receiver,this was also the funcion of the gas key,the carrier pice (and gas key) and the charging handle are the reason for the upper guide rail in the upper receiver(the guide rail in the side gas cut AR-10 is smaller then the one in the gas key AR-10).


The lack of a upper receiver guide rail in the prototype rifle make impossible for the use of a carrier guide pice and for the alignment of it with the cam pin head (the cam pin head cant be exposed out of the carrier as there is no space for it.What i am trying to find is the way for the mechanical operation and placement of parts with the prototype rifle,a photo of its bolt assembly is needed.

Thank you.

The bolt from the second rifle from the top,note the receiver tube,the butstock comes out and the bolt slides in.

Is there more of that bottom picture?

There is but i i can't show it,it from the same ARMALITE INFORMATION PACK from the next image,the bolt it is from the same rifle.

Basicly the but stock is unlocked and rotates to come out,the receiver tube is exposed and the bolt assembly and spring come out,the tube is made out of a machinenmetal tube as the upper receiver(that is welded to the tube) and trigger box are made out of stamped metal,the trigger box rotates down as with the MP44.The image is bad as it does not show the mechanical action of the bolt assembly.

http://www.ar-10er.com/