[Dean]

Hello sidhartha

I am also constructing a 16" carbine.

Look under the early lugers section under the heading "1902 carbine attachment".

The attachment of the frame extention is challanging. It is more difficult on a modern stainless model (which is what I am attempting).

On the original carbines, a slot is milled through the lower reciever to accomodate the extention. It then looks like they are then welded (brazed/soldered?) together from the inside. Care must be made to provide sufficient clearance for the take-down lever.

The new Aimco/Orimar/Stoeger stainless models are more difficult. The frame is cast very thin in this region. In addition, 416 stainless does not weld nicely. The only solution I have thought about thus far is to not mill the frame. Instead, I was thinking of contouring the frame extention to a tight match of the front of the trigger guard and frame. There is room for a screw through the frame from the inside where the takedown lever is. Two additional locating pins could be placed at topmost and lowest portions of the frame extention where it contacts the frame to provide extra rigidness against the long moment arm of the extension.