I just ran into something interesting.
My other Hadar stock came in today, and since I had three AK receivers laying on my desk, I tried sticking one into it.
It wouldn't go. It was too wide.
Tapco generic bent from a flat, TX_Dogblaster stainless AKM blank, and the .062 Coldsteel blank. None of them would fit.
I dug into the box of bits I'm supposed to send to chopper eventually, and tried a piece of 1966 Chinese milled receiver. Dropped right in.
The Tapco receiver and Dogblaster blank were 1.365" wide. The Coldsteel was 1.40" wide. And the Chinese milled was 1.34" wide, and a snug fit in the Hadar stock.
I never knew milled receivers were narrower than stamped ones...
Is that what people mean when they talk about top covers and selectors for milled receivers vs. stamped ones? I thought it was just the shape, not the size.
Harrumph. A standard trunnion slides right into the Coldsteel receiver. I thought I had to narrow the trunnion to make things fit; at least, that's what I've read was necessary for the .062" Chinese receivers.
So, did Coldsteel bend these wrong, or is there a top cover that will fit? For that matter, it's going to need longer axis pins, too.
Is it a bulged receiver blank? The straight trunnion blanks may take standard trunnions without narrowing them. I remember some issue with the FCG pins because if that with some blanks. Do the FCG pins fit across inside the stock? The Chinese receivers are narrower inside. The Bulgarian 1.5mm receivers are too. I have heard some of the straight Cold Steel blanks are wide, even the thin ones may be a bit. Some of them have the FCG pin holes X and Y a bit off too. I do like the Cold Steel bulged RPK/ Yugo blanks though.
No, it's just a spare Romanian trunnion. I couldn't see hogging the stock out to clear a Yugo trunnion if it was just going to be a 6.5 or 7.52x39.
Okay, I understand now. Do the FCG pins fit across the width of the stock?
No, it takes standard Galil bits. Well, except for the extra threaded hole under the barrel. There are some shallow slots to clear the barrel pins when you drop the receiver in; you can see them in the pictures earlier in the thread.
Well to figure out the "correct" width of an AKM receiver I guess measure the trunnion width and add two thicknesses of the sheet metal.
The flatside Yugo and 1.6mm Chinese receivers were normal width on the outside, to take standard top covers and axis pins. They used narrower trunnions to make everything work.
At least, that's what I remember from the old threads at gunsnet, which have reverted back to the primordial electrons whence they came. I remember pictures of people cutting Romanian trunnions to fit thicker Chinese receivers, anyway.
The 1.6mm Yugo trunnions are 1.21" across; the 1mm Romys are 1.25".