I am using an M85 PAP pistol as the basis of a budget-minded pseudo-Krinkov SBR. Manticore stock, Stormwerks folder mechanism, etc. - you know the drill.
One change I particularly wanted to make was to replace the unsightly Yugo pistol grip with a classic AK pistol grip. However, when I looked more closely, I found the upgrade is not as simple as just switching out the parts. The problem is the acute angle of the pistol grip screw on the Yugo receiver, as illustrated in the photo below:
Fortunately, it was a relatively simple task to make an adapter with off-the-shelf parts; some M6x1 threaded rod (Grainger), an M6x1 coupling nut (Grainger), an M6x1x60mm cap screw (Ace Hardware), and of course a pistol grip (Tapco). I also had a scrap red Tapco pistol grip lying around, so I sectioned it to give me an easy way to check the fit of the parts (and to show you, the reader, how everything goes together). Here are the steps I took:
1) Cut a piece of M6 threaded rod about 2" long
2) Screw on the coupling nut, clamp the assembly in a vise, and use a BFH to introduce a bend into the threaded rod as shown. Some adjustment of the angle may be required - later photos will show what we are trying to achieve with this step.
3) File down two opposing flats on the coupling nut, such that the nut will fit inside the pistol grip as shown below.
4) Shorten the M6 cap screw to fit, then slim down the screw head to fit into the recess of the pistol grip (I chucked it up in a drill press and hit it with a file).
5) Screw everything together with a generous application of Blue Loctite. The photo below shows the arrangement of the parts.
Here is how the pistol grip looks on the finished rifle:
That's it - the whole thing took me about an hour to execute (including the trip to Ace).