View Full Version : Romanian WUM - need help - Trunion Rivets
03-23-2004, 10:03 PM
I've degreased and inspected the WUM I received and I now notice that the
upper four front trunion rivets are still in the barreled trunion. They are cut off flush with the surface of the trunion. How do I get them out without pulling the headspaced barrel out of the trunion? This was supposed to be a new, never
before assembled kit, and it looks like a new one - but why are there rivets in the trunion holes?
Any help would be appreciated. :)
I've got more than a few FAL's under my belt but these AK's are a different ball game all together. Looks like fun. :sidegrin_
Bama . . . . Over . . . . .
03-23-2004, 11:39 PM
It could be unfired, but is isn't unassembled. They lied to you, my friend.
You need a drill press to get the rivets out. (A mill would be better.) First cut them off flat, then center-punch them and drill them with an undersized bit, then a larget bit, until you get them weakened so you can drive them out.
The rivets that go into the trunion alongside the barrel are a problem. You don't want to drill into the barrel, so measure the depth to the barrel and don't go any deeper. You'll have to reach in alongside the barrel and pull the old rivet heads out from the front.
I assume you intend to do a screw build. If you're going to rivet the trunion into the new receiver, you're going to have to pull the barrel, rivet the trunion, and re-press (and re-headspace).
03-24-2004, 07:16 AM
>>>>If you're going to rivet the trunion into the new receiver, you're going to have to pull the barrel, rivet the trunion, and re-press (and re-headspace).<<<<
PackRat, is this really the case? What will the rivet compress against if the barrel is removed? (I had planned to do a rivet build but now am unsure).
Bama . . . . . Over . . . . .
03-24-2004, 07:36 PM
I have no idea how you head the rivets in the barrel space; I assume you put something in there to make flat heads on them, or use flat-headed rivets put in from the inside. The rivets are not butted against the barrel, though; they are in a space in the trunion, and you can get them out to do a screw build. I've given up the idea of building any more kits for a while (money is extremely tight now and I can't afford the trunions), but when I can, I'm going to try to find someone who will rivet the trunions and press and headspace the barrels. After I get these three kits built, I won't be building any more. If I were, I would convert Saigas instead; it's cheaper and easier, and makes a nice shooter. (I've got one of them setting here also, ready to join the other 2 I've converted.) And I'd start with a 16" .308, instead of adding to the 7.62x39s. But it's so difficult to shoot, or even get to the range now, that I doubt I'll be shooting much anymore.
If there's anything I can help you with, though, I'll be glad to try.
03-24-2004, 08:41 PM
You can use a riveting jig, sold by a few people (here and on the web) if you want to rivet the trunnion to the recvr.
If these are the WUM's from inrange, I would (and plan to on mine) drill out the old rivets, leaving the bbl in the trunnion, then tap, screw, test fit, apply loctite, screw again,
Its very nice that the bbl is already in the trunnion....good stuff.
When a AK rifle is a assembled the trunion is riveted in the receiver and then the barrel is pressed in. If a parts kit has the barrel pressed into the trunion the rifle was assembled and then cut down.
Rivets come with the head formed already on one end. On a AK rifle the rivets on each side of the barrel have flat heads. The end without a head is heated red hot and then the rivet is inserted from the inside of the trunion and a bucking bar is used to hold the rivet in place. Pressure is applied to the rivet with the bucking bar while a air hammer with a tip on it that is cupped like this ) to produce the round head of the rivet.
03-25-2004, 08:19 PM
Wow! this is looking a lot more involved than I had expected! :uhoh_smal
I just got a Northern Hydraulics 6 ton press yesterday and it looks like I'll be
checking out a trunion riveting jig soon. (will a six tonner do the rivet job?)
Sounds like tapping and screwing the upper front four holes would be easier and
then riveting the front two lower holes. I might go that route.
I do have access to a riveting jig that would work for most easy to access
rivets - just not the front trunion rivets.
What other "gotcha's" should I be looking out for?
Do I need an offset rivet tool for the trigger guard rivets or will a straight one work?
Thanks for all your feedback guys! I'm a learnin' here . . . . . :)
Bama . . . Over . . . . .
03-25-2004, 08:30 PM
JA, I don't think the rivets are heated before heading. They are soft steel which is easily upset.
Steel rod can be used for the rivets, but the length is fairly critical; it has to be long enough to form the head, but without excess length that would leave material with no place to go.
The only rivets on a AK rifle I have done was the rear receiver trunion installing a side folding stock on a fixed stock Chinese rifle. Not having a rivet gun I heated the rivets and used a ball peen hammer. I guess with a air powered rivet gun heat wouldn't be needed as it would be doing all the work.
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