The whole idea was crazy.
The bolts are a BEAR to machine and hold in the Kurt.
The pins on the rocker arm are from needle bearings.
The spring comes from a site called "Asian Engineer".
The acorn nuts have to be milled and tapered 7.5 degrees.
The AirSoft 9MM clamps are almost useless on 9MM mags (no adjustment/don't hold) unless you shim them with neoprene wafers.
From that failure alone came the adjustment-bolt idea.
These work on every 1x3 metal mag I have: HK, SR-25/Armalite, SAR-48, M14, and other AR-10 derivatives.
I wanted to see what everybody though and wondered if anyone else had found a mag coupler
that didn't cost $150 bucks (HK Parts). I tried for months.