Differences in AK underfolder receiver?

[xLusi0n]

What are the diff between the receivers for an underfolder and a regular stock AK? How hard is it to switch between the two?

[Shady]

totally different

[cmace22]

completely different receivers and rear trunnions. its possible to machine for an underfolder but costly to do so. you have to have it pinned open anyways or have a muzzle extension added to keep to 30" or above. underfolders are not as comfortable to shoot as a normal fixed stock or even a side folder. best bet is to buy a nodak spud receiver and do a swap.


underfolder receiver


normal receiver


underfolder trunnion


normal trunnion

[nicoroshi]

Rivet holes, and underfolder holes is the difference along with different rear trunnions.
If going from an UF to solid stock you'd need to drill a couple of trunnion holes, and fill the UF holes.
If going from solid stock to UF you'd need to drill for the UF, the UF trunnion holes, and patch a couple of rivet holes needed for the solid stock.

Doable but wouldn't be the prettiest thing.
Yea, you could weld the holes needed to fill but the metal would be of a different type therefore take finishes differently (except something like rattle can paint or duracoat) that penetrate the metal (park or blue).

Why not just buy another rifle witht he stock you desire instead of cut, and weld on one you own?

UF rear trunnion:


Solid stock rear trunnion:

[cmace22]

Rivet holes, and underfolder holes is the difference along with different rear trunnions.
If going from an UF to solid stock you'd need to drill a couple of trunnion holes, and fill the UF holes.
If going from solid stock to UF you'd need to drill for the UF, the UF trunnion holes, and patch a couple of rivet holes needed for the solid stock.

Doable but wouldn't be the prettiest thing.
Yea, you could weld the holes needed to fill but the metal would be of a different type therefore take finishes differently (except something like rattle can paint or duracoat) that penetrate the metal (park or blue).

haha, you found the same photos i just added...

one thing i never liked about underfolders is the fact that you have to remove the mag (30rnd) if you want to transition between folded and unfolded.