I have a transferable M60 machine gun that I bought from RIA back in the day. The paperwork lists "Rock Island Armory, Inc." as the manufacturer. On the gun itself, "RIA" is stamped on the bottom of the channel (sheet metal portion of the receiver). The trunnion has the usual Maremount Saco markings on the top, and the serial number is stamped on the left side (of the trunnion). These are the only markings.

Is this a "registered trunnion" or a "registered receiver"? I've heard that a "registered receiver" is preferable. Why is that? What parts of the receiver (if any) can be replaced if they are damaged or wear out?

Interesting.  My RIA gun has the serial number and other info all stamped on the sheet metal, and I think that's pretty typical for RIA guns.  That said, you likely have a mil-spec forged trunnion, which is not typical for RIA guns.  

As Tony makes clear, whatever the serial number is on is the key part that can't be replaced.  Hopefully your trunnion is in spec and remains so.  Key issue is whether the barrel fits snugly in the trunnion.  If it does, you're good.

Joe

tony_k wrote:



Then that sounds like I have a "registered trunnion" and can replace the other parts of the receiver. But I dunno...

I was talking to the guys from Desert Ordnance at the Knob Creek show. They had a nice unit that consisted of the rails, channel, and bridge all riveted together and Parkerized, for $1,000. On my gun, the channel wasn't properly hardened and got a little bunged up when some guys I let shoot it had a jam and got carried away trying to clear it. (I sure learned a lesson that day.) It's been fixed, but you can tell by looking closely that there was damage there. Anyway, it seems I could use the Desert Ordnance replacement unit if I carefully drilled/ground out the rivets and the welds holding my receiver together. The Desert Ordnance people said that they no longer use welds, but just rivet the components together using hardened rivets, and that the receiver stretch gauge is a worthless piece of junk. (I question that advice.)

Here's the problem, as I see it –– the only indication that this was manufactured by RIA is the "RIA" stamped on the bottom of the channel. Otherwise, the markings on the trunnion would indicate that this is a Maremont gun. If I were to replace the channel, there would be a mismatch between the gun and the paperwork, as regards the manufacturer. Would it be kosher to restamp "RIA" on the replacement channel?

you might check with the folks at Ohio Ordnance Works.  They're highly recommended, should you need a repair.  They can probably help with your question as well.

Good luck,

Tony

Yes, I've had dealings with OOW. They do great work, and are reliable. Desert Ordnance will also do repair/refurbishing, if I send them the receiver.

Considering the value of the gun, I really don't want to let it out of my physical possession. It's not that I don't trust these shops, but you never know what might befall in shipment, etc.

So that leaves a "do-it-yourself" solution. According to my discussion with the folks at Desert Ordnance, installing their rails/channel/bridge assembly is doable. I would have to grind out the welds and rivets holding the original rails to the trunnion. Then, the new rail assembly would be riveted in place. (Desert Ordnance does not recommend using welds, and they don't recommend the receiver stretch gauge.) They use hardened rivets, as opposed to the softer rivets originally used. These rivets, in order to be mushroomed, either have to be heated red-hot (which would destroy the hardening), or installed with a special hydraulic press (which is what Desert Ordnance uses). As an alternative, couldn't the exposed ends of the rivets simply be tack-welded in place?

To me it sounds like you have the serial number and maker mark are two different components.  

The serial on the trunnion which RIA used from a SACO demil and their own makers mark on the channel.  Most RIA guns have the serial and maker markings on the channel (mine does anyway) as RIA transitioned to making their own trunnions in house at some point.  I presume after they ran out of clean Saco demils to use.

This is where the complexity comes in regards to replacing the sheet metal.

26 USC 5842 - Sec. 5842 states the following.

(a) Identification of firearms other than destructive devices
Each manufacturer and importer and anyone making a firearm shall identify each firearm, other than a destructive device, manufactured, imported, or made by a serial number which may not be readily removed, obliterated, or altered,  the name of the manufacturer, importer, or maker,and such other identification as the Secretary may by regulations prescribe.

26 USC 5861  Sec. 5861 states the following.

§5861. Prohibited acts
It shall be unlawful for any person—

(g) to obliterate, remove, change, or alter the serial number or other identification of a firearm required by this chapter; or

(h) to receive or possess a firearm having the serial number or other identification required by this chapter obliterated, removed, changed, or altered; or

Title 1/Non-NFA firearms can have any marking removed or altered except the serial.  Title II it doesnt appear you really can’t mess with any of the markings defined by regulations prescribed by the Secretary.

In this case I don’t believe it would be legal to remove the maker marking on an NFA firearm as they are defined in Tres Sec regulation 479.102... of which USC Treasury Code 26 part 5861 states that these markings "as defined by treasury regulations" cannot be obliterated or removed.  

I am not sure how this would play out if the maker marking is on an easily removable part like a quick change barrel, where regulations do technically allows all other markings besides serial (which must be on the receiver) to be engraved.  However, there was recently an article in SAR by Mark Barnes about folks who messed with the original model markings on transferable HK machineguns (HK94 to MP5) and made their guns contraband as a result.

I would be pretty leary about removing the original manufacturer markings (the RIA stamp on the channel) on a 30K transferable machinegun.  I beleive alot of folks wouldn't consider purchasing (unless the price was really discounted) a M60 that had a huge section of its receiver replaced by the previous owner via a rivet tack weld operation and of which some of the original manufacturer markings were lost in the process.

Given what you have at stake, (i.e a $30,000+) gun of which legal and build pedigree is of upmost importance to future buyers this is what I would do if I were you assuming you ever wish to sell it….  

I know people say never write letters to the ATF, but in this case I would get approval in writing from the ATF on exactly what you want to do. i.e. replace the damaged sheet metal channel on a RIA M60 and make sure it is legal to lose and/or remark the original manufacturer mark onto the new channel.  

I would then either ship the gun USPS Registered mail to Desset Ord and insure for the max 25K liability they allow.  Alternatively, you could book a direct flight and personally deliver it to Dessert Ord for the rework and then go back to pick it up when it was done.

Good luck with whatever your decision is and I hope it all turns out for the best.

Thank you. This was very helpful. It's beginning to look as though I should leave well enough alone for the time being. Really, the damage to the channel is not that noticeable, and it doesn't affect function. The question is whether that damage lowers resale value more than a replaced rail assembly would. From what you say, maybe not.



Yes. I have an early RIA gun (that I got directly from them in 1982). They apparently used a salvaged Maremont trunnion, milled off the original serial number (leaving an oval "cartouche" shaped depression), and stamped their own serial number in that spot. They then stamped "RIA" on the bottom of the channel.