So, my bad luck strikes again. My receiver came in for my yugo M70 front end kit and after picking it up and coming home I noticed something wrong. my new receiver has bulges like on the RPK and the kit is for one without one. upon research, I found that the m70 is supposed to have this receiver, and somehow mine is a "mutt"  It still has a yugo front trunion, so I'm thinking that the rifle was a M90 SBR that had a barrel change and apparently all that was around was the m70 barrel assy.


the three together


RPK receiver front end


kit receiver


new receiver



I have a couple options at this point:
1) replace the front trunion
2) return the receiver  and find a suitable replacement

I'm leaning on the first option, and saving the trunnion for a possible SBR or pistol build. is there anything else that needs to be considered?

If you replace the trunnion, you will have to check headspace and possibly do some work to get it right. I'd get another NDS receiver if I was you and save some hassle.

I thought all the yugos had the heavier "grenade launching" receivers?

Before the commercial receivers became available when the 1st batch came in from Centerfire, a lot of folks were happy to see the regular style AKM receivers. That is, when their bores weren't sewer pipes

Aren't you out at sea?

If it were me...
I would turn a piece of 8620 steel down to where it would just slip-fit (just a slight-interference fit actually) into the hole that is out of position.  
Then I would cut the plug .250" shorter than the width if the trunion so that the ends of the plug sit beneath the surface of the trunion.
That would leave some room for me to TIG-weld the plug permanently into place using some 80-NI filler rod.

Then I would (just snug) chuck the trunion into my cnc-mill and dial-indicate the trunion flat, tighten it down, and mill the welds flat.
I would then take the receiver and chuck it up into the mill.
Edge-find the top, and the front of the receiver and set that as my "zero" (i.e. origin) coordinate.
Set up either a wiggler or a center-finder in my quill and establish the coordinate positions of all three holes a, b, and c and record the positons into the cnc-controller.
Then I would take my trunion and chuck it back up into the mill and edge-find the front and the top, just like i did the receiver.
I could then check the positions of holes b and c by running the mill over to those and checking with a reemer or a gauge-pin.
If holes b and c check-out, then I would run the mill over the the previously-recorded position for hole a and drill/ream the new hole and be done with it.
Should probably take 2-4 hours of screwing around to complete.

I was, it was just a workup det, I got home on thursday.


oh and btw, I got a message from a guy that has the opposite situation as me, he has a flat receiver and a bulged front trunion, so we may be working out a trade on that.

The non-bulged Yugo kits are much less common and are worth more.  Just buy another reciever and sell the one you have.