dantheman Posted February 9, 2022 Report Share Posted February 9, 2022 (edited) I recently bought a dummy 1928a1 built on an aluminum receiver with GI parts. After getting the barrel off the aluminum receiver, which was glued on with red loctite it seems, I noticed it was damaged somewhat. Appears someone got heavy handed getting the old receiver stub off. Based on these pictures would this barrel be safe to shoot? The chamber will need to be cleaned up some but Im mostly worried about the material missing in the threads. Thoughts? Edited February 9, 2022 by dantheman Link to comment Share on other sites More sharing options...
BRMCII Posted February 9, 2022 Report Share Posted February 9, 2022 There is one thread that is damaged above the ground away spot that can do some minor damage to an inner thread if screwed into the receiver unless the damaged part is removed or realigned. The remainder of the threads look serviceable and the ground area doesn't appear large enough that it would compromise the integrity of the joint from firing.The greatest stress on the threads is the torque from tightening the barrel. In my opinion, there is little or no possibility that the threads would strip from firing. Hypothetically, if the threads started to strip, the barrel would move forward and the next round would not fire.If the barrel loosened, it would be immediately visible from the angle of the front sight.You don't mention the kind or extent of the damage to the chamber, a further reason to not use it.I am completely baffled trying to understand why you would even consider installing a damaged barrel onto your receiver.....?!?! FWIW Link to comment Share on other sites More sharing options...
laurencen Posted February 9, 2022 Report Share Posted February 9, 2022 do you have a picture of the chamber area under the grind mark area, Link to comment Share on other sites More sharing options...
RoscoeTurner Posted February 9, 2022 Report Share Posted February 9, 2022 NOS barrels can still be had for a reasonable price. The barrel you have would be better to use as a display barrel or a fishing weight. Link to comment Share on other sites More sharing options...
Roland the Thompsongunner Posted February 9, 2022 Report Share Posted February 9, 2022 I agree with what was said above buy an NOS barrel the guns are a fortune now. It would be a different case if it was a super rare gun and impossible to find parts for then you would clean that up carefully and install. Dont take the chance Link to comment Share on other sites More sharing options...
TD. Posted February 9, 2022 Report Share Posted February 9, 2022 dantheman,If me, I would loctite that barrel back on the dummy receiver and enjoy the dummy gun as is. There is a reason certain parts are used on dummy guns. You have a great example in hand. If you need a barrel for your Thompson gun, there are plenty of good options available. This barrel is not one of them. However, you posed an excellent question and the pictures you posted are something we can all learn from. Great answers above by some very knowledgeable forum members (fishing weight . My advice to everyone is that it does not pay to go cheap in the machine gun community. This is a very expensive (but enjoyable) hobby. Link to comment Share on other sites More sharing options...
Chopper28 Posted February 9, 2022 Report Share Posted February 9, 2022 Why take the chance of messing up an expensive receiver when barrels are readily available at reasonable cost. It is not worth it. Just my .02 Link to comment Share on other sites More sharing options...
Motorcar Posted February 9, 2022 Report Share Posted February 9, 2022 "Dummy" gun barrel, display and enjoy. Link to comment Share on other sites More sharing options...
dantheman Posted February 9, 2022 Author Report Share Posted February 9, 2022 Thanks everyone. Wasnt really planning on using it, just curious what others thought. The chamber seems fine other than having some gouges in the entry area. If anything it may get the muzzle threaded and used for blanks on a SBR. I hate wasting original parts. Otherwise it will remain on a display receiver. The original milled grip mount also had the lug that engages the barrel threads ground down. Im going to try to repair that by welding it up and reshaping. Link to comment Share on other sites More sharing options...
reconbob Posted February 10, 2022 Report Share Posted February 10, 2022 If the threads can cleaned/fixed so that the barrel screws in easily , and if the chamber and mouth of the chamber are ok (so that the cartridges feed) the barrel should be ok. When you shoot a Thompson the torque of the bullet thru the rifling tightens (as opposed to in-screwing) the barrel. When we barrel a Thompson - which fairly often - we first test fire the gun with no grip mount and the barrel only hand tight. We do this so if something is wrong we have not committed to the grip mount and torquing the barrel and the barrel can be easily removed. Shooting a hand tight barrel does not make it tighter on the receiver - it unscrews easily. But I also ask why you are bothering with this barrel. And, FYI waffenmeisters sells a perfect repro grip mount for $67. Not worth welding and reworking a damgaged one. Bob Link to comment Share on other sites More sharing options...
dantheman Posted February 10, 2022 Author Report Share Posted February 10, 2022 If the threads can cleaned/fixed so that the barrel screws in easily , and if the chamber and mouth of the chamber are ok (so that the cartridges feed) the barrel should be ok. When you shoot a Thompson the torque of the bullet thru the rifling tightens (as opposed to in-screwing) the barrel. When we barrel a Thompson - which fairly often - we first test fire the gun with no grip mount and the barrel only hand tight. We do this so if something is wrong we have not committed to the grip mount and torquing the barrel and the barrel can be easily removed. Shooting a hand tight barrel does not make it tighter on the receiver - it unscrews easily. But I also ask why you are bothering with this barrel. And, FYI waffenmeisters sells a perfect repro grip mount for $67. Not worth welding and reworking a damgaged one. BobThanks Bob. As I said above I don’t intend on using this barrel for live fire, but if it is ok for blanks then I’d rather use an original part for something useful than just throwing it out or putting it on a dummy. Im aware of the repro grip mounts as well, but thanks for the reminder. As far as repairing the grip mount, as thing goes; I’d rather save the original part and use it. I’m not at this to make money, it’s a hobby. If I can save something from the scrap bin then that’s what I strive to do. Waste of time? Probably, but at least I tried. Link to comment Share on other sites More sharing options...
john Posted February 11, 2022 Report Share Posted February 11, 2022 (edited) Possibly a barrel pulled from a gun that was rewatted and weldment ground out to remove the barrel in a rewat attempt?Or possibly a (movie?) gun that had a hole drilled in the top of the nose of the receiver and the barrel spot-welded into place to alleviate looseness and retain front sight alignment?Bob Bowman had several Colt Thompsons at Knob Creek years ago to get them parkerized inexpensively. They were to be sold for $7k each and were guns from the "Untouchables" movie, among other movies. Bob bought a huge lot (3-Semi trailers full) of registered broken NFA from Stembridge that he was told were too crappy to be sold off, but all papered. He was restoring a few at a time.A few of the ones he showed me had a hole in the top that had been spot welded in like this and he said it was done by Stembridge to fix loose barrels and keep the comp and sight straight.This barrel seems to fit that type of repair. Wonder how weld-heat would affect wear in the chamber area? Wonder where those Colts went, who bought them? Edited February 11, 2022 by john Link to comment Share on other sites More sharing options...
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