Who knows how to fix Thompson feed lips? Seems like a shame to throw it away.

[Doug Quaid]

You know the tale already - dropped a full mag, bent up the feed lips a little.

Been sitting in a drawer for 3 or 4 years.

Are there any gunsmiths who can fix it?   Is there a feed lip guru among ye?

Thanks

 

[timkel]

There was a member that made a feed lip mandrel type tool. This tool was used to repair bent feed lips.

[ltcajh]

I don't know if this will help you, but when I got a new drum it wouldn't feed right. I bent the feed lips open ever so slightly and it worked!

[SP Sarge]

Forum member Tiz makes and sells the feed lip repair tool.

 

[Doug Quaid]

thanks

looks like everyone is happy with the Tiz tool.

I'll PM him.

[katanafred]

23 hours ago, Doug Quaid said:

thanks

looks like everyone is happy with the Tiz tool.

I'll PM him.

I have the tool ... the only problem I have with it is the requirement to ream out the magazine catch hole on some magazines in order to insert and tighten the bolt that holds the tool in place in the magazine. This makes me uncomfortable, but of course if the magazine is not working, anything is worth a try.  I prefer disassembling old USGI magazines, cleaning them up, adding some protective lube, reassembling - then using a micrometer to compare the lip spacing against magazines that I know work in my particular gun. If out of specs, I'll use a magazine lip tool to bend and adjust them to match the measurements on my good magazines until I can get them to function properly.

[Rabbit57]

I have only had one bad mag, but the Tiz tool worked.

Mark

[Tiz]

On 9/18/2023 at 1:21 PM, katanafred said:

I have the tool ... the only problem I have with it is the requirement to ream out the magazine catch hole on some magazines in order to insert and tighten the bolt that holds the tool in place in the magazine. This makes me uncomfortable, but of course if the magazine is not working, anything is worth a try.  I prefer disassembling old USGI magazines, cleaning them up, adding some protective lube, reassembling - then using a micrometer to compare the lip spacing against magazines that I know work in my particular gun. If out of specs, I'll use a magazine lip tool to bend and adjust them to match the measurements on my good magazines until I can get them to function properly.

Just a note of clarification on the use of the Magazine feed lip repair  tool. The included instructions clearly state that if the alignment bolt will not fit it is because the inside folds of the spine of the magazine are interfering, in which case a 5/16 inch reamer will provide the necessary clearance to insert the alignment bolt. Not all magazines may require this step, some mags will have sufficient clearance and will not require a reamer to be used. In any case the magazine catch hole is NOT enlarged in any way. The magazine catch hole is 11/32 so the 5/16 reamer will ONLY provide the necessary clearance to the inside folds of the mag spine. The mag catch hole will not be enlarged or altered in any way.

[Maine-iac]

On 9/20/2023 at 8:55 AM, Tiz said:

Just a note of clarification on the use of the Magazine feed lip repair 

 

-snip-

 

The mag catch hole will not be enlarged or altered in any way.

Huh, I was wondering about that. 

[Doug Quaid]

On 9/18/2023 at 1:21 PM, katanafred said:

 I prefer disassembling old USGI magazines, cleaning them up, adding some protective lube, reassembling - then using a micrometer to compare the lip spacing against magazines that I know work in my particular gun. If out of specs, I'll use a magazine lip tool to bend and adjust them to match the measurements on my good magazines until I can get them to function properly.

Not a bad idea.  I've had plenty of success with eyeballing and kludging stuff over the years.