
28 Thompson Barrels
#1
Posted 19 September 2003 - 02:26 AM
#2
Posted 19 September 2003 - 08:03 AM
I haven't seen very many West Hurley barrels, but one way to tell the difference is that WWII GI barrels usually have 28 or 29 cooling fins, not counting the large flange at the breech end. The new manufactured barrels I have seen have approx. 27 fins. Generally, all WWII GI barrels shouls have a manufacturer's code on the flange, a "P" proof or a witness mark. The GI fins are usually somewhat squared off and the new barrels have more rounded fins. If the finish is too shiny and new looking it's probably a new barrel.
#3
Posted 19 September 2003 - 09:55 AM
#4
Posted 19 September 2003 - 04:38 PM
#5
Posted 19 September 2003 - 04:50 PM
#6
Posted 19 September 2003 - 05:23 PM
#7
Posted 19 September 2003 - 05:25 PM
#8
Posted 19 September 2003 - 05:29 PM
#9
Posted 19 September 2003 - 05:38 PM
#10
Posted 19 September 2003 - 05:43 PM
#11
Posted 19 September 2003 - 06:21 PM
I do not believe that any military TSMG left the factory with a witness mark. The only scenario I can visualize as an exception would be that a particular gun required rework for some reason prior to being accepted. The only reason to apply one is if there was intention to remove the barrel and then subsequently reinstall it on the same gun. That’s why Colt used both serial numbers and witness marks; to allow fitting, disassembly, finishing and subsequent reassemble. This was very common in the firearms industry world wide in earlier times. But I believe the military guns were assembled from pre-finished parts and that there would be no reason to witness mark them.
Now, that said, I commonly apply witness marks to any barrel of any gun with features that require a specific alignment (such as fixed sights) and needs to be removed and then reassembled. It is possible that GI armorors would do the same, although I’d bet if they pulled a barrel it was going into the scrap pile.
So, do military barrels exist with witness marks? Of course, some were applied by my self and many others working on them, I suppose.
I will admit to not having seen a broad spectrum of NOS parts barrels (those I have seen were not witness marked) and would love to hear from those who have had an opportunity to handle many dozens of the same. Phil? Doug?
#12
Posted 19 September 2003 - 06:38 PM
#13
Posted 19 September 2003 - 06:52 PM
#14
Posted 19 September 2003 - 07:01 PM

By the way - first post - Great form!
#15
Posted 19 September 2003 - 08:00 PM
My smooth barrel threaded for comp new in wrapping has a "o" and an alinement mark.
My AO Bridgeport M1 has smooth barrel with "p" and a alinement mark on barrel and a mark on reciever to line them up. The M1 was reworked at Mt. Rainier Arsenal.
My WH has no mark on the fins or barrel or reciever.
#16
Posted 19 September 2003 - 08:24 PM
Hope this helps
Roger
#17
Posted 19 September 2003 - 09:16 PM
#18
Posted 19 September 2003 - 09:31 PM
If a 1921 A Colt with a serial number under 1000 was fitted with a second model Cutt's compensator by Auto Ord in Hartford, and updated with heavy acutator to become an overstamp Navy, the original barrel would have been changed, and the serial number would no longer be present.
#19
Posted 19 September 2003 - 09:36 PM
In a review of American Thunder I note two 28’s. The first on pg. 47 is a fined barrel and shows marks on both the barrel and receiver (it is interesting that they don’t line up however), and on pg. 53 is a smooth barrel with no marks on either barrel or receiver.
I would really like to hear from the NOS parts guys.
#20
Posted 20 September 2003 - 06:08 PM
Attached is a picture of two NOS Savage made 1928 barrels unwrapped from the cosmolene. Both are threaded for the compensator and have no groove for the compensator pin, so they haven't been on a gun. Hope this helps.
