tangotag said:
I guess I was going with what K-Var was selling as Russian sidefolders (determined by the mass here that they were really Bulgarian).
I used the K-Var "Russian" sidefolders that take the smaller diameter stock pin and trunnions and they fit just fine with the NDS-1KP.
http://www.k-var.com/shop/product.php?p ... 251&page=1
I also had no problem with fitting the Russian sidefolder from K-var.
I have both a Bulgarian and a Russian sidefolder and trunnion assembly from K-Var. I tried them both in the KP receiver (mentioned above) and they both fit perfectly. The NDS KP receiver is cut for the 6 degree angle used by the sidefolders with the 'old' 4.5mm hinge pin. So the conclusion here is that as long as your using a sidefolder assembly with the older 4.5mm trunnion, the NDS KP will work fine.
The good news is that virutally all triangle sidefolders anyone is going to find here in the US are the older 4.5mm style, so really it doesn't matter if you're using a sidefolder of Bulgarian or Russian origin, it's gonna fit fine.
However, I also happen to have one of the very rare new 5.5mm Russian triangle sidefolder and trunnion assembly from the Izhmash factory. This sidefolder was available from Rusmilitary (in England) but has long since been sold out. Same for Tantal Collector. This new sidefolder assembly is cut for a 4 degree receiver... and it does fit in the NDS KP but obviously the sheetmetal doesn't line up well with the trunnion. It can't because there's a 2 degree difference in angle. It doesn't look right.
So the long and short of this is that the NDS KP receiver will work with any 4.5mm triangle sidefolder... and generally speaking, probably 99% of the triangle sidefolders out there are 4.5mm. It also will work with any 5.5mm side folder, but the sheetmetal will not line up correctly with the trunnion.
-Thirtycal