Thompson MGC info.

*** Originally posted by eatdirt ***

Hey guys . This is my first post on this site and I am looking for some help . I am buying a Thompson mgc from someone who has had it a long time , maybe 25 to 30 years ( wood and color in great shape , stick and drum mag ) . They took great care with it but lost the instruction booklet. Does anyone know where I can get a copy of the instructions ?? Also I am only getting a few of the brass rounds with the unit , where can I find a good place the buy a bunch ?? Any info will help a lot Thanks .....

*** Originally posted by claymore ***

Francky is the man for the rounds, check out the buy and sell section and you will see what he is selling and you can PM or email him.

I should think he can send you a set of instructions but i can always scan a copy and email them to you if you want.

What rounds do you have are they an open round or do they have a bullet head and a piston inside, the open ones are old paper cap style and you will need a new chamber and bolt (which Francky can supply) to get the gun working on the new style round. You will want the new style CP round as the old open rounds are hard to get and the paper caps even harder + the new rounds work better.

*** Originally posted by eatdirt ***


Thanks Clay for the reply. The info on the rounds was great only problem I am waiting for the snail mail to deliver my package .Don't know which type of rounds are coming with it . I have only seen the thompson by pictures . If I do have to replace some parts as you said how much would think that would cost ??? Thanks Ron

P.S. This is my first modelgun / I have been wanting a thompson for years and well the price was right !!!!

*** Originally posted by mark ***

Hi um, eatdirt

Welcome to the forums! It seems that the MGC MP40 and the Thompson brings in the most questions and interested people to the forums. If your example of the MGC Thompson is the one with the allen head screws on the top of the receiver then it is possibly the earlier version with the "papercap" style of cartridges. (The open ended cartridges that claymore alluded to in his post.)

Some if not all of the MGC submachinegun series (MP40,Sterlings,Thompsons etc) that where imported into the U.S. in the 1960's-1990's had their bolt faces cut at an angle and their chambers blocked to comply to some obscure law. So, don't be too suprised if your bolt and chamber is like this. Some of the mid-80's MP40's and the Thompson's where imported with intact bolts and chambers(with out their proper "detonators") but, these are fairly rare.

The parts that you would need for the "CP" style cartridges are not that expensive but, the receiver does need some dremel work done on the inside to clear the later style bolt (if it does need one that is) it isn't that hard to do and it can be done in a few minutes. The old chamber can be removed by removing the small flathead screw from the receivers underside jst in front of the magazine well. Once the screw is removed, the chamber can be slipped out of the receiver if its not stuck. If it is stuck point the muzzle upward and tap on the receivers sides with a rubber mallet or a piece of wood until the chamber falls out. (the stamped steel ejector needs to be removed before the chamber can be removed)

Now, the cartridges are fairly expensive and they do wear over time also, they come 10 to a package and if you shoot it alot you will soon need at least a full drum (39) or stick (20) magazine full then, you will probably need at least one more magazine and finally, you will need more caps too...

Quote :

P.S. This is my first modelgun / I have been wanting a thompson for years and well the price was right !!!!

Since this is your first modelgun be sure to clean it as soon as possible paying close attention to the cartridges and the steel parts like the magazine, extractor,ejector, springs etc. as the phosphorus "smoke" that is generated from the fired caps is corrosive and it gets everywhere!

I use a solution of hot water, vinegar and baking soda to clean off and neutralize the phosporus residue. Pay close attension to the cartridges after firing them as they will "sieze up" and refuse to dissasemble easily with out lots of force if they sit for a few days (or in some cases, hours!)

When shooting the MGC "Thompson" or any semi or full auto modelgun be sure that there are no breakable objects any where in line of the ejection port as the cartridges are fairly heavy and will dent as well as break valueables both near and far! (my kitchen cabinets as well as the ceiling bear modelgun cartridge scars

If you pay careful attention to proper loading/cleaning of the cartridges and the modelgun(s) they will be extremely fun to shoot and since they are fairly quiet too they can be shot almost anywhere without too much worry..

*** Originally posted by eatdirt ***

Thanks Mark for the good advice . All the info. you gave me will be very helpfull to this new guy ! I contacted The seller of the thompson about the allen screws and he said 'why yes there are two allen head on top . I never noticed that " Sounds like I might need a few Parts . O well at least I will have a thompson to add to my collection of WW II firearms. No way could I afford a real one M1A1. also try to explain that cost to the wife ( OUCH ) .




Hey Clay , I will need a copy of the instruction mannual for the thompson . If there is any to get one so I can see maybe exploded view and disassembly and parts I. D.



Thanks RON

*** Originally posted by mark ***

You are welcome.

The early MGC Thompsons with the allen bolts on the receiver top usually have an "open" barrel that will-with the proper chamber- vent gasses "smoke" out the muzzle. These open barreled versions can be far more realistic as they smoke and discarge lots of gas out the muzzle which looks better than just out the ejection port like the later closed barrel Thompsons do.

I noticed that you refered to the M1A1. This MGC Thompson is the 1921-28 version with the top mounted cocking handle. Hudson, CMC (defunct) as well as Tanaka produce the M1 and the M1A1 versions of the Thompson modelgun. The Hudson is the M1A1 version while the Tanaka is the M1 version.

*** Originally posted by cerwyn ***


Hiya

I've just bought another MGC Thompson and this one has the 2 allen screws on top of the receiver. I couldn't figue out why the detonator chamber refuses to stay in place even though the single screw is tightened fully.
I assume from reading the posts above that this has been converted from the old paper cap rounds to cp.
Should the new style detonator chamber just slip into the barrel exactly like the newer type gun or do further mods need doing?
All I can think of rigt now is a longer screw...

Cerwyn

*** Originally posted by mark ***

cerwyn wrote:

Hiya

I've just bought another MGC Thompson and this one has the 2 allen screws on top of the receiver. I couldn't figue out why the detonator chamber refuses to stay in place even though the single screw is tightened fully.
I assume from reading the posts above that this has been converted from the old paper cap rounds to cp.
Should the new style detonator chamber just slip into the barrel exactly like the newer type gun or do further mods need doing?
All I can think of rigt now is a longer screw...

Cerwyn

If the chamber won't stay in place i would venture to say that the screw that you have currently in place isn't long enough to hold the chamber in. I ran across that problem in my converted early MGC Thompson in as much that the original afixment screw was too short to hold the new chamber in place. So, i merely replaced it (actually, that's not quite correct, it took quite some time to locate one that worked!) with a longer example.

The chambers should slip into place with a fairly loose fit until they are almost flush with the chamber walls. (it should not move around too much side to side without the screw holding it.) If your chamber is really "sloppy" someone might have done some gunsmithing on it already and messed it up..I have seen some MGC Thompsons that had solid steel plugs pressed into the chambers that where slightly oversized and made the chamber walls a little looser after their removal.

*** Originally posted by claymore ***

On the old chamber it had a metal strip integral to the chamber that fits into a recess, if you look at the chamber you will see this recess, the screw, screw's down onto this strip. On my cp chamber i simply glued a thin piece of plastic to the chamber and hey presto the chamber stays secure, or of course as mark says get a bigger screw

*** Originally posted by reemo ***

Lay a piece of an industrial staple (like on an cardboard shipping box) in that channel........just break off a piece of copper staple and lay it in there, its the exact same width.........the grub screw will press against the strip you made, holding the detonator cup in there firmly.

*** Originally posted by mark ***

Excellent suggestions guys!

I couldn't quite remember that the older chambers featured the small integral strip on their O.D. i suppose that this small "strip" was intended to align the chamber with its gas holes that lead into the open barrel.

*** Originally posted by reemo ***

mark wrote:

Excellent suggestions guys!

I suppose that this small "strip" was intended to align the chamber with its gas holes that lead into the open barrel.

Bingo......it was "keyed" like this to keep holes to the vent left and right of the septum (or divider) in the barrel.

*** Originally posted by cerwyn ***

Hey guys you done it again!
Thanks very much for all your help on this one.
I was beginning to think I'd thrown my money away with this one.

If the barrel will vent smoke I'd guess that the base of the detonator should be drilled then?

The chambers on my MP40 and M3A1 are drilled to allow venting

Thanks very much

Cerwyn

*** Originally posted by reemo ***

Found some pics of the old style paper cap detonator and chamber (cup)........you can see the "key" that is molded into the cup that once occupied that slot we are discussing.....the width of a staple from a cardboard box.

The second photo is a clear view of the slots cut into the base of the detonator chamber that allows the gas and smoke to pass.

*** Originally posted by mark ***

Both of the replacement chambers (stainless steel) that I have had lacked the proper holes and I ended up drilling them. As far as the "rib" on the outer part of the chamber, my replacement chambers lack that feature too. I will have to try your "fix" Reemo....

*** Originally posted by cerwyn ***

Thanks Reemo,
Your photo of the chamber and it's rib are just what I needed.
Should be easy enough to drill the chamber's base too.
Thanks again, I'll let you know if it's successful, I've no doubts it will now.

Cerwyn

*** Originally posted by eatdirt ***

Hey guys I need some help .
I finely got my mgc thompson 1921 in the mail and I'm puzzled about a few things . First the "caps" are solid brass and when I work the action it will chamber a round . The finned barrel is hollow but none of the internal parts look anything like the other pictures I have seen on this post. It looks more like a real bolt assembly .
So I guess i won't be firing any caps soon by the looks of things . But I did get both types of front grips and a hollow (Fake ) drum mag .
The Item looks and feels great . like new condition . My question : is it worth less than some of other thompsons of it's kind that are out there ? Thanks RON

*** Originally posted by mark ***

Ron,

By "caps" you must actually be refering to the cartridges. Many of these MGC modelguns that where sourced through the main importer in the U.S. "the collectors armory" where ordered with extra dummy solid brass cartridges that where of course, optional. I would like to see the chamber area in your Thompson as I am not sure what you mean:

"The finned barrel is hollow but none of the internal parts look anything like the other pictures I have seen on this post. It looks more like a real bolt assembly"

Anyway, it sounds as if you received a good standard edition, display only MGC Thompson, with un-cut parts. This is not bad news actually as you received the normal version that was sold in the the early 1980's by the collectors armory. It is fairly easy to get it back to its former cap firing "self" with a few parts if you wish but, it involves buying a few components from board member "Francky"

As far as worth is concerned that is purely subjective to each of us. The version that you have sounds like it is an early open barrel that usually is a nice version to have since it vents out the muzzle. The functional drums can be bought as well as the proper "CP" cartridges that it needs.

The fact that you received both of the foregrips is nice. But never handle the MGC Thompson exclusively by the foregrip only as the zinc bar that it is attached to will break (if it isn't already)

*** Originally posted by eatdirt ***

Mark You were right on about the barrel , It is hollow but it does have a metal bar that splits the barrel in half . The rounds I have are solid and have a dimple on the end ( looks like a hollow point round ) . Got nine of them with the unit . The safety switch works when I pull the bolt back . The auto/single switch does not seem to do anything . When cocked and then pull trigger bolt slams into chamber fine .
I wish I had a camera to show you some pic. ( spent too much money on ammo for mil. surplus firearms ) .
Thanks for the advice about the front grip . upon bench cleaning the unit I changed grip right away . Looks better with the m1 type grip also I can put on a sling now.
What do you think it would cost to make this unit a blank fireing model ? Or would it be better to keep it in the condition its in .
Thanks for the help RON

*** Originally posted by mark ***

Ron,

The cartridges that you describe are the standard solid brass dummy rounds that the collectors armory offered for the MGC "1967A1" .45 as well as other modelguns like the Thompson. These solid rounds are nice to cyle in the action but they are practically wortless otherwise. The Thompsons safety is ment to be left on the off position to operate the action. Now as for the selector, when you select the SEMI position, try to pull back the bolt with the trigger held back. Does the bolt stay in the open position when you release it with the trigger held down? If the bolt in the SEMI position stays to the rear then it is working properly.

I would think that it might cost anywhere from $80-200 to get it working again firing caps. The high side of the quoted cost would be due to the functional 39 round drum magazine, a new bolt assy chamber (with a "detonator") and spare cartridges. The cost of getting it to fire caps can be fairly expensive but, it will be worth it.

Now, a word of explaination about "blanks" This does not use actual "blanks" that are far too loud and much more powerful (and not to mention illegal as of this point..The cap firing modelguns are quiet but the are fun and best of all: Legal....

*** Originally posted by eatdirt ***

Mark , You are 100 % Right with all your info. about the selector switch-- auto/ semi fire mode . The action works just as you said in your last post . Nice to talk to someone who knows which end is up ...
The fake rounds don't do much more than look good . If I cycle a round in the chamber it does not eject too well if at all . If I change some of the parts to use modern cartridges will the action cycle o.k.
Thanks RON

*** Originally posted by cerywn ***

Reemo wrote:

Lay a piece of an industrial staple (like on an cardboard shipping box) in that channel........just break off a piece of copper staple and lay it in there, its the exact same width.........the grub screw will press against the strip you made, holding the detonator cup in there firmly.

Thanks for this Reemo... It's taken me this long to get around to trying it but your suggestion of slipping a copper staple nto the locating groove and retightening the standard length screw works a treat!
Perfect firing, no detonator movement, just great!
Thanks again!

Cerwyn

*** Originally posted by reemo ***

Cool! Glad it worked Cerwyn!