M1A1 Thompson Gurus

BREWINZ

NES Member
Rating - 100%
10   0   0
Joined
Jan 16, 2016
Messages
643
Likes
352
Location
Central MA
I'm interested in purchasing a semi-auto Thompson. I found a model from Auto Ordnance that has a 10 round mag (TM110S). However, the TM series doesn't appear to be compatible with preban mags. Am I wrong? Any way modifications could be made to accept prebans?

Edit: Stick mags only. Don't want a drum.
 

1919FAN

NES Member
Rating - 100%
16   0   0
Joined
Oct 19, 2006
Messages
1,173
Likes
696
Any mag will work. And they even take drums as well there are still alot of preban mags floating around. I picked up ten of them from the subguns forum
 
Last edited:

67ray

NES Member
Rating - 100%
167   0   0
Joined
Feb 27, 2006
Messages
1,776
Likes
830
To use a preban you will need to dremel the mag catch hole about 1/8" upwards for it to fit, if you don't want to replace the GI mag catch.
 
Rating - 100%
8   0   0
Joined
Apr 22, 2013
Messages
1,543
Likes
386
Location
Principality of Sealand
Drums are a PITA to load into the gun. Old stick magazines will work, you just have to file them a bit. Also consider getting the spring kit. It will make pulling the bolt back a lot easier.
 

Zappa

Road Warrior
NES Member
Rating - 100%
27   0   0
Joined
May 14, 2008
Messages
43,678
Likes
13,945
Location
Living Free In The 603
M1 and M1a1 are not cut to take drum mag.
This^

The models with the side cocking lever are not designed to take a drum mag, but the versions with the top mounted cocking lever will take either sticks or drums.
However, to install or remove a drum mag is a real PITA because the modern semi-auto versions don't have a built-in bolt hold open mechanism and requires use of a device called a "third hand". Original F/A models didn't have this problem because they fired from an open bolt.
 

maritz01

Instructor
NES Member
Rating - 100%
8   0   0
Joined
Jun 23, 2007
Messages
222
Likes
12
Location
South Shore MA
When I made my 1927 a SBR I sent it out at the time to Thommygun.com and he had a guy do all his mill work. Have a 1928 lower where it was milled to fit the upper receiver. Then made it that the selector (semi/auto) was rotated it would take the place of the third hand and cause the bolt to stay open.
 

BREWINZ

NES Member
Rating - 100%
10   0   0
Joined
Jan 16, 2016
Messages
643
Likes
352
Location
Central MA
Excuse my ignorance. I've been doing some reading, but MA law is ever changing and clear as mud. Can I SBR a Thompson? I see no reason why not, but my intention is to have a 10.5" barrel on it and I'd hate to find out later that I can't.
 

67ray

NES Member
Rating - 100%
167   0   0
Joined
Feb 27, 2006
Messages
1,776
Likes
830
You can SBR a Thompson. But, there is a snag now because SBR can't be FA-10ed properly that is well discussed on this forum. They avoid the definition of "assault weapon" by the fixed stock, no bayonet lug, and no flash hider. Plenty on this site to read up on.
 

BREWINZ

NES Member
Rating - 100%
10   0   0
Joined
Jan 16, 2016
Messages
643
Likes
352
Location
Central MA
You can SBR a Thompson. But, there is a snag now because SBR can't be FA-10ed properly that is well discussed on this forum. They avoid the definition of "assault weapon" by the fixed stock, no bayonet lug, and no flash hider. Plenty on this site to read up on.
Thank you, sir.
 

gerrycaruso

NES Member
Rating - 100%
17   0   0
Joined
Jun 9, 2006
Messages
2,946
Likes
757
Location
westford
I had a 1927 semi-auto and sold it when I got a 1928 full-auto. I don't know much about Thompsons but this is what I've learned. Only the 1921, 27 and 28 can use both a stick or a drum but as has been mentioned the drum is kind of a pain. The bolt is much easier to pull back on the full auto and will stay back. Full auto stick magazines have a round hole to lock them into the gun. This hole can be filed into an oval and the magazines will work in the semi-auto but cannot be used in the full auto any longer. The gun is very heavy but I'm not carrying it around and it keeps the recoil down.
 
Top Bottom