Will the semi-auto Thompson magazines work in the real deal?

Do they even make a semi auto mag for them?

The semi auto mags have the catch hole machined out so the bottom of the hole is .10" lower. The semi trigger frame is .10" shorter (height) than the original, to keep FA parts from fitting.

All the semi mags are just mil surplus that have had the catch hole opened and a quick refinish job.

Quoted: The semi auto mags have the catch hole machined out so the bottom of the hole is .10" lower. The semi trigger frame is .10" shorter (height) than the original, to keep FA parts from fitting. All the semi mags are just mil surplus that have had the catch hole opened and a quick refinish job.

+1

Take a dremel and lenghten the hole a bit..should fit in no problem.

i gotta admit that that's the first time i've ever heard about semi/auto mags

What about the 50 round drum mags?

Quoted: i gotta admit that that's the first time i've ever heard about semi/auto mags

I learn something new everyday on arfcom.

No wait a minute, I'm putting the semi-mags in the real thing...

I'm heading to rent a MG and I wanted to know if an old mag from a gun I sold would fit.

Quoted: No wait a minute, I'm putting the semi-mags in the real thing... I'm heading to rent a MG and I wanted to know if an old mag from a gun I sold would fit.

I have a semi Tommy, so I am no expert on FA Thompsons. From what I have read on another forum, semi mags need to have the mag catch hole welded up and the hole reshaped back to original specs.  I have posted your question on a Thompson board so hopefuly I can update this with an experts opinion.

Quoted: What about the 50 round drum mags?

The drum mags made by West Hurley (70's 80's) and Kahr (current) are mostly junk. They are not made to spec. Takes some major tweaking to get the things to run right. Kahr had major issues with their 50 round drum that came out after the AWB expired. People were having to send the drums back repeatedly to get Kahr to fix them.

Kahr is coming out with a 100 rd C-drum this fall(?). They say they learned their lesson from the 50rd drum mess. The C-drum is suppose to be made to spec and won't be realesed for sale until ALL quality issues are dealt with.

Quoted: Quoted: No wait a minute, I'm putting the semi-mags in the real thing... I'm heading to rent a MG and I wanted to know if an old mag from a gun I sold would fit. I have a semi Tommy, so I am no expert on FA Thompsons. From what I have read on another forum, semi mags need to have the mag catch hole welded up and the hole reshaped back to original specs.  I have posted your question on a Thompson board so hopefuly I can update this with an experts opinion. Quoted: What about the 50 round drum mags? The drum mags made by West Hurley (70's 80's) and Kahr (current) are mostly junk. They are not made to spec. Takes some major tweaking to get the things to run right. Kahr had major issues with their 50 round drum that came out after the AWB expired. People were having to send the drums back repeatedly to get Kahr to fix them. Kahr is coming out with a 100 rd C-drum this fall(?). They say they learned their lesson from the 50rd drum mess. The C-drum is suppose to be made to spec and won't be realesed for sale until ALL quality issues are dealt with.

I so gotta get a Thompson Semi Auto is this true

Had one and sold it long ago...

In order for a full auto Thompson mag to be used in a semi-auto gun, the magazine catch hole has to be filed upward.

This is because the semi-auto receiver is lower than the full-auto to preclude installing full-auto parts.

This means that the modified magazine will no longer work in a full-auto gun, since the magazine will be held way to low to feed.

You cannot use a drum magazine in an M1 Thompson.
The receiver and trigger group are not cut for the drum on the M1 or M1-A1 guns.

One thing I do know, full auto mags converted to semi have the bolt hold open tab ground off the follower.