newmexicocoonass

Excellent video. Now we know! I've seen a number of websites that claim they are American issue. Just false marketing I guess.

That makes sense. I have seen original Thompson spare parts and cleaning kits, but never any screwdrivers. Thompson's are all pins except the stocks.

PhilOrd is making M1 A1 bolts, so that's always an option. I would be looking at saving wear item parts in the lower also.

I'm a gunsmith, so I always think about those things too. And, my bolt was made in 1943. Worth having the specs, parts do wear out. That was my point of this post. It is not difficult to press in a new firing pin if you have the right tools. I've wanted a Thompson since I was probably 10 years old - finally got one, and I want it to run a good long time.

The one I'm looking at is American issue, but I can't really see what it might have to do with the Thompson.

Anybody know what these were used for exactly? Curious about the slots on the side. Thanks NMCA

I normally shoot reloads, but tried a box of Fiocchi 230 off the shelf & had a FTF. Did anybody (GU) read the original post? I was asking for specs, not comments and opinions. As indicated, Bob from PhilOrd was kind enough to email me back with the correct specs for the M1A1 firing pin (.040-.002"); as .044-.050" are for the 28/M1 hammer-actuated firing pins. Sounds like Fiocchi is not a good choice for my Tommy. Thanks all. NMCA

Fired primers look good, one FTF with Fiocchi ammo. Strike looked ok. Just playing it safe.

Hi Jim - I had one misfire the other day; that's what got me looking. Got an email from PhilOrd saying spec is .040-.002", so my .0395" is OK. I would've thought it'd be more like .050".

Richard+ thanks for the info, I ordered a gauge from Apex just to have really. .044 & .050" I got off a picture of another gauge. Replacing the firing pin is easy if you have the right tools; I'm just hoping the bolt will fit in my lathe chuck & make it real easy if needed. NMCA

Is the M1A1 spec the same as for the m1 (.044-.050")? Mine comes in at .0395". Thanks NMCA

Bob - understood. I do color case hardening from time to time and my cut off point is WW1 and later - there's a lot of steels that I can't identify or predict how they will respond to real bone and charcoal color case hardening. I didn't think truing the sear notch would hurt, but when in doubt, ask. Appreciate all the great info !!!

Sounds like I need to ID the bolt. If it is cased. I wouldn't want to cut through it. NMCA

Some great information coming out here, thanks all. So the bolts are cased rather than through hard? NMCA

Planning on trueing the sear notch on my M1A1 bolt as part of a tune-up. The bolt itself doesn't seem as hard as I thought it would be; file checking indicates 22-25r. Anyone know what the metal is and what the heat-treat specs are? I would imagine they were through-hardened, but I'd like to learn more before I proceed. Thanks !! Tommy

Good to go now, here is the M1 with the BRP picatinny adapter and Vortex Viper installed, trigger polishing & overtravel, and modified mag channel & release. Now, considering barrel options to lighten it up some. NMCA

Anybody got a take-off 10.5 inch barrel? NMCA El Q

Shot it at the range today. When I got the Viper dialed in, the red dot was sitting on the back of the front sight !! Now I've got the picatinny back on the adapter plate, and the Viper on its mounting plate. Will try it again manana 👍

Progress. Drilled & tapped a BRP picatinny adapter so I can use the rail or red dot. No extra holes in the receiver. EZ Pull kit is in, and smoothed out the trigger as per another post I found here somewhere. Modified the frame catch and added a trigger overtravel stop. Flared the mag channel. I was hoping to shoot it at the local match tomorrow, but it'll have to wait til I get some more mags!! NMCA El Q

Getting ready to SBR my Kahr SA. Going from stock 16.5 to 10 or 10.5. Question: Are all Thompson barrel threads the same? Will a USGI 10.5 M1/A1 barrel fit on a Kahr SA? Will a 1928? Second question, does anyone know the weight difference between a M1 plane 10.5 and a 1928 finned ? Thanks !! NMCA El Q

Wow that's cool !!!

The factory sights are pretty high. The DeltaPoint has an option to come with a built-in rear sight. If you made your mount on the thompson tall enough (or trimmed the front sight shorter), you could get this lining up. https://www.leupold.com/gear-and-accessories/accessories/deltapoint-pro-rear-iron-sight

That looks like what I'm after, and maybe even some protective ears to disguise the sight. Most likely I will not be running a suppressor. I did see one kind of reflex sight that had a channel in the housing to allow use of the stock sights.

Good advice, thanks. I'll be comparing sights this week, and things will be clearer then.

That's a good point... Probably smarter just to drill and tap. El Q NMCA