There wasn't a whole lotta info about this so I figured I would throw a post up.  I LOVE this setup!

Quick part list:

-POF MP5 Full Size (SBR)
-Poly SEF Lower
-B&T Optics Mount
-Holosun red dot
-M.I. MLOK rail with BCM covers
-BCM Grip
-Magpul Pic sections
-X300U 1k lum
-Sig Minimalist Pro Folding Stock.

Now, the buttcap that comes with the POF pistol has a nub infused in the plastic that the sling swivel attaches to.  I took a dremmel to it to make it flush-ish (also ground down the pic rail a bit) and threw some aluminum black on it.  I picked up 5-slot Magpul MOE rail section, lined it up to the cap, and drilled some new holes and attached it with some new bolts.  I got the idea from this thread https://www.hkpro.com/forum/hk-clone-talk/504500-how-make-inexpensive-sig-folding-stock-adapter-mp5-hk93-style-guns.html

Anyway, I locks up tight in both directions, is completely low-pro when folded, and feels good on the gun.  I only put 200 through this configuration at the range today but it was SWEET.  I dig it.

Sizing is wonky (I apologize)

Folded up with some coupled 15rnd mags.


Opened up with a traditional curved 30


With a straight 30


The reverse

Any wobble to the stock? Seems iffy.

Completely solid.  No movement at all.