Tommy gun compensator threads

[MMcfpd]

Would any of y'all perhaps know what threading is used in an Auto Ordnance Thompson compensator?

I just had the admittedly silly idea to perhaps use one on the .45 ACP AR I'm gathering parts for.

 

[dstorm1911]

they are pinned along with the front sight. at least the originals are, I just got through building 30 of em last week from original new/old stock parts..... for a customer who supplied original NFA Registered recievers...

 

[MMcfpd]

Do you mean then that there are no threads, just some sort of hole/slot for the pin?

For whatever reason, I can't manage to adjust my computer's settings to allow me to see the graphic you attached.

 

[dstorm1911]

the front of the barrel is belled up the comp is press fit then a pin goes through right under the front sight with non Cutts barrels such as the M1s and M1A1s at the far end of the table the sight is just band mounted with the pin through it...... no thrrads needed

 

[dstorm1911]

BTW with authentic original comps going for around $150 ea by themselves not really cost effective either...

 

[dfariswheel]

I don't know about the current Thompson semi-autos, but the older Numrich Arms and Kahr Arms guns had threaded muzzles.

On the older Numrich guns the compensator was actually GLUED ON with epoxy, and you had to warm the metal to 300 degrees to get it to break down so the compensator could be screwed off.

At least the early Kahr Arms guns were still treaded, but they used the original Auto Ordnance SMG method of a threaded muzzle and a cross pin to lock it in place.

Before attempting to get the compensator off, FIND OUT WHAT YOU HAVE.
Trying to pull off a threaded compensator isn't going to work.

The Thompson M1 and M1A1 type guns with NO compensator had smooth belled muzzles and a cross pin. The guns with a Cutts compensator are/were threaded and either epoxied or pinned.

 

[dstorm1911]

Dfariswheel, we have 4100 original unissued parts sets left (the Thompsons we shipped to Russia for WWII that they never used) and of all the cutts comped barrels (about 1/3 of the total) so far I've disassembled a couple hundred finned and smooth all have simply had the comp pinned in place with a very tight press fit, I'll see if I can remember to try and get some pics this week if I get a few minutes, The owner decided to seperate a few of em to sell the components seperatly the non-comped barrels I can usually punch out the sight pin then tap the sight off with a rawhide mallet but not the comped barrels they require goin to the press...

 

[theken206]

I just got through building 30 of em last week from original new/old stock parts..... for a customer who supplied original NFA Registered recievers..."



I will give him first born for just one of those suckers..... well not really but man that sounds nice.

 

[dfariswheel]

dstorm1911:

That's really odd.
The original Thompson 1921/1928 guns with Cutts compensator were all threaded.

At least the later WWII Savage and Auto Ordnance guns with Cutts were threaded, and no US or British Ordnance manual I've ever seen describes anything but removal methods for the threaded and pinned Cutts guns.

Many of the current Russian imports Thompson parts were taken from the American tanks we sent the Soviets under Lend/Lease.
The Lend/Lease authority was told to ship the Soviets new American built tanks, and they assumed that meant the same setup as shipped to the US army: A COMPLETE tank, right down to the one-per tank Thompson SMG.

The Russians had no real use for the Thompson's so they were removed and stored.
It's these stored guns that are nor being sold as parts.

I'm wondering if they used barrels from the M1 or M1A1 guns briefly.

 

[dstorm1911]

Well I did pull a few more today just outa curiosity and yep there are both some threaded some not.......... The ones today are from a new crate of 1928A1 barrels and yes all of these were threaded while in the old crate of M1 barrels only found a few that were threaded most were just the usual press fit from h#ll hmmm Gonna be busy gettin these MG34s built so they can ship but as soon as am done with that am gonna pull a few samples from the other crates and see what I find, We have barrels from the M1s but a few m1a1s we have mostly 1928a1 barrels

 

[MMcfpd]

Can you tell what the threading dimensions are?