AK Question (Norinco Mak-90)

CobrayKid

I heard chinese front trunions have a smaller hole than euro AK's. Im wondering if this was true, and if someone had to replace a front trunion on a mak-90 sporter, if Id have to get a norinco one, of if there is some other variant that would work. Otherwise would a whole trunion/barrel swap-out be a better course of action?
Thanks
Eric

AZEX

The bbl shank on chinese guns is 19mm as opposed to 24mm for Euro guns (except some RPK types).

If you're going to put another chinese bbl in the gun, you can avoid tearing the gun apart, which you're not supposed to do, since the trunnion on chinese guns is the serialized part.

So, technically, what you have to do, is press in another bbl, establish headspace, weld the bbl in place and clean up the bbl pin retaining hole and press in the pin. You want to avoid making hte hole "oversized", since there's not a whole lot of clearance between the bottom of the slot on the bbl shank, and the inside of the bbls chamber. So any "oversizing" will weaken the rifle at the chamber.

Feel free to email me with questions. I've done many of these but avoid changing bbls out in Chinese guns due to the fact that they're very soft and bend quite easily.

D.

CobrayKid

Thanks for the info AZEX

The barrel on the rifle is fine, aparantly there is a chip/damage to the front trunion and thats why the gun is/was so cheap. I was going to just pull the whole trunion/barrel/front assembly and try to find a new trunion to press the barrel into, or entire front end to replace it if its cheaper.

Is an RPK barrel superior to the regular chinese ak barrel?

AZEX

Not on the chinese guns. The RPK type Chinese guns and postban variants (NHM 91 etc...) have the same skinny 19mm bbl shank, the same trunnions etc...UNLIKE the euro types (Yugo, Romanian, Russian, Bulgarian) which use larger "bulged" trunnions and thicker receivers than their standard AKM counterparts.

The chinese guns use 1.5mm receivers already, but never have I seen one with a bulged trunnion or a larger shank bbl.

Please send me a pic of the "chip/damage" and I'll give you some idea as to what I think could be done to save it.

As I said, you cannot "legally" removed the trunnion, it is the serial numbered part.

D.

barto

AZEX-
Not to seem a wise-* but I'm sitting here looking at a Rom. & a Hung. AK and they both have the ser. no. stamped on the front trunnion & were that way when I bought them (as kits).
To the best of my knowledge, the BATFE considers the RECIEVER as the rifle in the case of ALL AK's. Trunnions be damned.
[?]barto[?]

AZEX

Correct, with regard to parts kits.

You'll also note that all new AK receivers, while they'd only be shells in Hungary or Romania are ACTUAL receivers which require serialization here in the USA.

The Trunnion, on an imported Chinese gun, is the part that contains the serial number. Removal of that trunnion, constitutes "obliteration" of the serial number at the federal and state level, because that's how it was imported...with the SN on the trunnion.

Could someone with patience, eventually get the ATF Technology branch to give them permisson to "relocate" the SN from the trunnion to the receiver shell? Maybe.

D.

CobrayKid

So does that mean a Mak-90 receiver is NOT considered a firearm if its stripped? That just seems....bad.

AZEX

It would seem to be correct, if for no other reason than by default.

But obliterating serial numbers, regardless of what component they're on, is a bigtime no-no.

But it's not just Chinese AKs, EVERY pre-89 AK and most postban thumbhole types brought in up to 1994 and even the WASR series of today, have the SN on the trunnion.

D.