PSL Front Trunnion Question

[LESchwartz]

I recently purchased another PSL Kit off GunBroker (stole it for the price I paid). I received it today and it's in perfect condition . . . except . . .

It seems like there was a serial number on the front trunnion, and one of the previous owners looked to have tried to remove with a dremel. This is interesting for two reasons:

1) My other three PSL kits didn't have s/n's on the trunnions. (The s/n was always on the Romanian-made receivers.) So it's a little odd that this one looks to have a s/n on the trunnion in the first place.

2) I heard that some AK's (MAK-90's maybe?) were imported without a s/n on the receiver, and that these rifles had a s/n on the trunnion which *was* the s/n. Demilling these rifles supposedly involved destroying the trunnion.

I can smooth out the dremel irregularities with a quick pass of my mill. But, I'm worried that for legal reasons, I should replace the trunnion instead of build on it. Even if it's legal, I'm worried that some LEO will think that I'm trying to deface a s/n -- so it might be best to spend a couple buck more for a receiver with the trunnions already installed.

Comments?

Larry

PS: I've already consulted with some folks via pm. I won't presume to re-post any of their comments here. I'll let them do so if they desire.

[allesennogwat]

The PSL receiver wraps around the trunnion quite a bit. All imported AK's that are imported with trunnion already in the receiver have the serial number only on the trunnion and not the receiver except the imported Yugo AK's. When the receivers have trunnion added in US usually the trunnion numbers are ground away to prevent confusion and only the receiver number remains. When receivers are imported without trunnions then the number is on the receiver. Most US built AK's have the trunnion number removed to only show the new receiver number. I forget exactly how much of the PSL trunnion is exposed.

On a side note years ago somebody wanted to change calibers or make a Krinkov out of a Chinese AK. They wrote ATF asking if it was okay to remove the front trunnion for "service". ATF responded that it was okay to remove the trunnion rivets for service. Funny thing was neither letter mentioned the fact that serial number was on the trunnion. Normally the part of the receiver that has the serial number can not be separated from the receiver even for service except by the maker. This is why HK91 to HK21 conversions have the serial number section "folded" instead of cut and welded to make clearance for the belt feed.

If you are making a home built receiver you don't need any serial number. If you are using a commercial receiver with a serial number on the receiver and not the trunnion, it is normal practice to remove the trunnion serial number leaving only the new receiver serial number.

[gunplumber]

This is a can of worms that ATF does not want to open.

Any AK with a serial number on the trunnion is technically contraband since the receiver is the serial numbered part.

I ran into this when I was converting a Sar-2 to full auto krink. The receiver had no serial number - it was on the trunion, which I was replacing. I ended up having to engrave the receiver with a serial number and write off the old serial number as destroyed.

[LESchwartz]

The AK kits I've built on all have a partial s/n on the trunnion (last four digits, iirc). The PSL kits have not had even a partial s/n on the trunnion. So it may be that there was a batch of PSL's that had the s/n on the trunnion and not on the receiver. Or it may be that they some have the s/n on the receiver and a partial on the trunnion. At this point, I can't tell if the trunnion's marking was even a s/n, let alone how many digits it was. (Though I'm pretty sure it's the later.)

I once had an interesting conversation with my transfer dealer. I once sold a kit I built on a 100% receiver, which had to come from an 01 FFL. He wondered why "there were two different s/n's on the rifle (with the partial on the trunnion differing from the one on the receiver). If he could be confused, then imagine some LEO if he thought I was trying to deface a s/n. (Note that since that occured, I've purchased my AK 100% receivers with the "custom s/n option", and matched the trunnion to the receiver.)

My conclusion is that it should be fine to build on the trunnion and use my mill to clean up the trunnion. However, it may not still be advisable do to the possibility of encountering an overzealous LEO.

Larry

[gunplumber]

There are Romy built PSLs. The 8 I bought had SN on trunion.

There are TN gun rebuilds on US receivers. Did those have SN on receiver instead? I had one but don't remember.

[NorincoKid]

That was me fighting you on that LES

CobrayKid on GB

Was a good deal.

[LESchwartz]

There are Romy built PSLs. The 8 I bought had SN on trunion.

There are TN gun rebuilds on US receivers. Did those have SN on receiver instead? I had one but don't remember.

I don't know the specific supplier details of any of the four I've had, since they were all purchased ad hoc on the secondary market (in other words, I buy them off GunBroker when I see a deal I can't pass up).

As I mentioned, this is the first kit that I've seen with any markings on the front trunnion. If you've seen some PSL's with full s/n's on the trunnion only, then the trunnion would be the serialized part. So you're correct about this being a can of worm. Or at least having the potential for becoming a can of worms. And since I can't tell if the number on my trunnion was a full or partial, I could end up with with two serialized parts on the rebuilt rifle -- one of which is defaced at that.

Given the potential legal ambiguity and the potential for an overzealous LEO, it may be best for me to just spend a couple extra bucks for a 100% receiver that has the trunnions already in it.

Larry

[LESchwartz]

I don't know the specific supplier details of any of the four I've had, since they were all purchased ad hoc on the secondary market (in other words, I buy them off GunBroker when I see a deal I can't pass up).


I can say this: The previous three all had threaded muzzles and chopped bayo lugs. This one has a pined muzzle and an intact lug. To me that indicates a different importer.

The photos on the TNGuns web site seem to show pinned muzzles and intact lugs.

Larry

PS: I've been in the habit of soldering on the MB's. I'm not quite sure what to do with the lug on this one though.

[LESchwartz]

That was me fighting you on that LES

CobrayKid on GB

Was a good deal.

The kit looks new. It ended up that it was missing the TG and the BHO. I've got some Romi TG's and I can make the BHO, so I'm very happy with what I paid . . . even if I have to discard the trunnion.

Larry

[LESchwartz]

In the end, I decided to play it safe and discard the trunnion. I purchased a 100% TNGuns "receiver w/ trunnions" from Centerfire -- It came with BHO and TG installed as well. Worked out great as far as I'm concerned.

Interestingly, the new "receiver w/ trunnions" had the s/n marked on the trunnion and not the receiver. This would indicate that in at least some circumstances the trunnion is the serialized part.

thanks for the assist,

Larry

[justashooter]

This is a can of worms that ATF does not want to open.

Any AK with a serial number on the trunnion is technically contraband since the receiver is the serial numbered part.

I ran into this when I was converting a Sar-2 to full auto krink. The receiver had no serial number - it was on the trunion, which I was replacing. I ended up having to engrave the receiver with a serial number and write off the old serial number as destroyed.

not so. if the trunion is riveted to the receiver, then it is "permanently attached", so good to go. permanently attached means connected by any means not seperable with the average homeowner's tool box. so rivets are as good as silver solder or welding.

your NFA conversion needed your maker's mark anyway. at that moment the serial number was your option. you could have used any trunion number on the form 1, or added one to the sheet metal by engraving, and either ground off or left any serial number on the trunion.

[gunplumber]

No - "permanently attached" is a legal definition usually applied to muzzle devices that includes specific methods of welding, specific temperatures of silver soldering, or specific methods of blind pinning. Riveting has never been on the list.

[allesennogwat]

In the end, I decided to play it safe and discard the trunnion. I purchased a 100% TNGuns "receiver w/ trunnions" from Centerfire -- It came with BHO and TG installed as well. Worked out great as far as I'm concerned.

Interestingly, the new "receiver w/ trunnions" had the s/n marked on the trunnion and not the receiver. This would indicate that in at least some circumstances the trunnion is the serialized part.

thanks for the assist,

Larry

I wonder if the serialized trunnions are from the commercial PSL's that ATF rejected because they had welded up third pin holes.

[gunplumber]

I wonder if the serialized trunnions are from the commercial PSL's that ATF rejected because they had welded up third pin holes.

Thats my guess too. But like I said, its a real can of worms. England for example the barrel is the serialed part and I've seen a glock from england with a blank SN plate on the frame.

The easy solution i think is to simply assign the receiver a number the same as the trunion.

I wonder how many AKs went off the radar when the transferring dealer used the serial number off the trunion instead of the serial number off the receiver? I still have people trying to tell me their FAL/L1A1 serial number based on the number on the lower from the original parts kit . .. .

[allesennogwat]

I remember an ATF letter that was a reply to a gunsmith that wanted to know if it was okay to remove the trunnion from a Chinese AK to perform mods such as caliber conversions, fitting European barrels and Krinkov conversions. The ATF response letter stated it was okay to remove the rivets from the trunnion to "service" the firearm. Neither the gunsmith's letter nor the ATF letter mentioned the fact that the only serial number on a Chinese AK is on the trunnion. Removing the trunnion would leave a receiver without a serial number.

[justashooter]

No - "permanently attached" is a legal definition usually applied to muzzle devices that includes specific methods of welding, specific temperatures of silver soldering, or specific methods of blind pinning. Riveting has never been on the list.

the opinion letter remarking on silver solder and blind pinning is in regard to muzzle attachments only. the guns that have been imported with serial on trunion only are your precedent in regard to the rivets. if that connexion was good enough to get them imported, it's good enough to use in building. so when you make a flat bent gun, you can transfer it if you add your name, city, and state, and use the trunion serial as the gun serial, as long as it is riveted or welded construction.

screw builds cannot be validated this way, as the average homeowner's tool box can seperate the functional part of the receiver from the serial number. where we really get into the fun is with older guns (and maybe a few newer ones?) that are serial nubered on the barrel. i suppose a re-barrel is considered far enough beyond the abilities of the average joe to be considered a permanent attachment. transfers of this type happen often enough.

permanantly attached can mean silv solder, welded, riveted, whatever, as long as something with that method has been imported or accepted in past. this is even good for barrel length. you could weld a 20" piece of steel fence post onto the bottom of a 3" barrel and put it on a rifle, as long as the "muzzle attachment" (angle iron) ended no less than 16" from the breech face and was reasonably so in line with the bore as to be considered a barrel extension. doesn't matter whether it functions as a bore or not. in that case, it's all about limiting concealability.

[gunplumber]

Please cite any ATF document using the term "average homeowner" or similar phrase in any way, shape, or form.

Or even better, any ATF document using the word "rivet" and "permanent" together.