MGC THOMPSON BOLT

You cannot get paper caps anymore so no idea if they are louder than the new caps, i would doubt it. A guy in germany did use pistol primers but had to make his own rounds to accomodate this, what other changes he had to make i dont know.

From the photo it looks like your extractor is one of the "dummy" ones without a claw to grab the rim, or am I looking at it wrong?

The 1st photo does seem to show a small lip for the rim to fit.

I was confused at first............but I think John is correct from looking at the pics. The first pics are actually from a different forum member. The pics posted most recently by the current member/poster sure look to be that of a dummy bolt and fake extractor.

I know asked this before, but since its hard to get 7mm caps,
can a shell primer from a low caliber such as a 25 auto be used as a substitute for a cap or are all shell primers the same?

Different primers have different levels of powder - this is true.

I would still not risk it. Even if you don't care about potentially damaging your model, you certainly don't want to injure yourself or anyone else.

You also would have to contend with the fact that the MGC Thompson does not have a firing pin in the bolt. I'd just keep an eye out for caps. My 2 cents.

Well I was going to use 25 auto primer dropped inside pfc shell, but I would not know how much stress the pfc shell could take

A PFC cap has something like 0.01g of powder. I would think a primer from any round would contain considerably more powder than that!

I'm going on the powder strength of certain primers

I purchased my mgc Thompson which came with a drum, 100 pfc caps and 20 off shells. I tested it, and fired off 5 shell in full auto which worked perfectly. But it's not open barrel, its blocked. How can I unlock my barrel without damaging the barrel?

I finally bought a mgc (my 3rd one) and was surprised it came with 100 7mm caps. But the question is once I fire the caps is is it some way I refill the used caps with powder?

Good news on the Tommy, the MGC was always a good firer.

I'd recommend not trying to unblock the barrel.
1: it could be seen as an attempt to convert it
2: the hardened steel inserts are cast during the moulding so your more likely to ruin the model

As for reloading caps, sadly not. unless you can find out the cap composition and replicate it, and as far as I know nobody has the recipe

It is a pain with the poor cap supply

I found a substitute for my caps if they run out, after i fired it I replaced one of the shells with an old fashion percussion cap and it worked! It was just a little smaller in diameter, but it worked, I couldn't tell.the difference far as sound.
Now my other mgc is early model with an open barrel and the smoke comes out the front for a nice effect. My other mgc I is a Hudson block barrel 1980

Do anyone know the grain composite of a 7mm pfc cap?
Is it 0.01, 0.1 or 0.2?

Nope

Leesmth wrote:

Do anyone know the grain composite of a 7mm pfc cap?
Is it 0.01,  0.1 or 0.2?

Active substance, as far as I know, was 0.01g red phosphorus.
Exact content is a trade secret of companies (Marushin/MGC) and is not published AFAIK.

Ok

I have MGC Thompson that I fire a lot but the shells become very dirty, I sanded the inside of the shells with 1000 grit sand paper just to polish the inside, by me doing this will there be a firing problem?

Well as long as its smooth that should be fine, just dont take much out or it wont seal well and that will be a problem. always clean rounds straight after firing they normally stay pretty clean if you do that. a good ultra sonic cleaner is a must and i just use washing up liquid and water and it works well.
The brass rounds will go dull over time and a real round tumbler cleaner will bring them back to new.
Oh! and a must is after every time you fire clean the round, use a Q tip for the inside and clean and lube the piston and seal, this means that when you finish firing the round wont be as dirty and clean easier plus firing will be improved.

Also do anyone know where I can purchase more 7mm plug fire caps? The ones I found (which was 2 boxes) I already used them up with my mgc Thompson. I started using the old school super loud plastic caps. Even though they fire they wont cycle the bolt back to chamber another round. There has to be somewhere in the U.S besides over seas that sell them?

A purchase they Denix Thompson a while back and was disappointed at quality. So I bought MGC bolt to replace the cut down bolt it came with. Second I drill a hole in the solid piece of metal in the chamber a inserted a detonator for plug firing caps. But I had to do a whole lot grinding with a dremel to smooth out all the rough edges. Last the magazine was a challenge, I found out the lip of the magazine was deliberately made high in the front and a round spring was inserted inside so it cant be pushed down to far without jamming. So I bought a real Thompson spring and dremel a small portion of the lip and loaded it up and fired it. And it worked! Just think I was about to sell it.

I have Mgc Thompson with a stick magazine and I notice it is the identical to the real Thompson stick magazine, are both of them are dentical? will a MGC Thomson stick magazine fit in a real Thompson?