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Pyrex
03-25-2014, 11:09 PM
Does anyone in here have experience casting for a machinegun? I'm chose a .45 as my next machinegun for the expressed purpose of firing cheap cast bullets. Is there anything I need to know out of the normal for casting for this purpose? The reason I ask is the higher heat of the barrel could cause excessive leading. Curious if anyone in here has some experience or could lend some suggestions.

btroj
03-25-2014, 11:14 PM
Don't use a single cavity mould.......

Pyrex
03-25-2014, 11:34 PM
Don't use a single cavity mould.......

:) hehehe

btroj
03-25-2014, 11:37 PM
Use a lube that handles heat well. Otherwise I would make sure you have a good load and fit, leading could build up fast if it occurs.

I will keep an eye out for results.

gmsharps
03-25-2014, 11:37 PM
The Thompson M1A1 is a good choice in that it is the cheapest version of the Thompson out there and I've found 200gr SWC HG 68 works just fine. Less lead than the 230gr RN and you are still shooting. They are very controlable and a blast to shoot.

gmsharps

.22-10-45
03-25-2014, 11:41 PM
The early British Maxims were chambered for the .577/.450 Martini-Henry ctg. And these were paper-patched..I would have loved to see the smoke screen laid down by those black powder loads! The P.P. will take care of leading..but your fingers are gonna be sore.

Bigslug
03-25-2014, 11:51 PM
Well, a legitimate machinegun (not a Gatling) barrel can easily get above the melting point of lead, but in the short time any single bullet is exposed to it, I doubt it will pick up enough heat to start to slag.

If the gun is coming to you heavily used, I would suggest slugging just the first inch or so of the rifling, in addition to the entire bore, and sizing your slugs to fit the worn throat. . .If that is indeed what you have. This will help prevent the gas blow-by that leads to leading.

Pyrex
03-25-2014, 11:51 PM
The Thompson M1A1 is a good choice in that it is the cheapest version of the Thompson out there and I've found 200gr SWC HG 68 works just fine. Less lead than the 230gr RN and you are still shooting. They are very controlable and a blast to shoot.

gmsharps

So why do you think the 200gr leads less than 230? Currently I have 1,000 230gr projectiles resized sitting in a bin I was about to load tomorrow to see how they do. What kind of harness are you running?

Pyrex
03-25-2014, 11:53 PM
Well, a legitimate machinegun (not a Gatling) barrel can easily get above the melting point of lead, but in the short time any single bullet is exposed to it, I doubt it will pick up enough heat to start to slag.

If the gun is coming to you heavily used, I would suggest slugging just the first inch or so of the rifling, in addition to the entire bore, and sizing your slugs to fit the worn throat. . .If that is indeed what you have. This will help prevent the gas blow-by that leads to leading.

It's a brand new bore, in good shape, hopefully should have a whole lot of life in it. I'm curious if I should keep the bursts slow and let it cool regularly to avoid leading. But, hopefully after a few months of experimentation I should have some good advice. I'm just hoping I don't have to wear a gas mask to shoot it.

dkf
03-25-2014, 11:54 PM
Maybe consider a coating like the HiTek for the bullets. You will be saving some major coin laoding your own with cast bullets and the coating is not that expensive.

Pyrex
03-25-2014, 11:56 PM
Maybe consider a coating like the HiTek for the bullets. You will be saving some major coin laoding your own with cast bullets and the coating is not that expensive.

I'm not familiar with HiTek, I need to look into that.

Bigslug
03-26-2014, 12:03 AM
So why do you think the 200gr leads less than 230?

I think he means that you pour 30 grains less lead per copy.

As to short bursts, that's just a good idea with most MG's. Remember that the air cooled stuff was designed to be portable to the guys who had to carry all their ammo with them. It's the watercooled guns that are the legitimate sustained-fire toys.

Pyrex
03-26-2014, 12:17 AM
Okay, well I'm on page 40 of the hitek pulled coating thread and it this appears to be one of the biggest things since sliced bread. Pretty interested honestly!

SODAPOPMG
03-26-2014, 12:44 AM
cast bullets in pistol caliber machine guns is not a problem just follow the standard procedures for size and lube
i shoot them in
1928 thompson 45acp just have to keep cleaning out the cutts comp as it tends to build up with carbon and lead very minor leading in bore 1000rds
mp40 9mm those Nazis made good barrels no leading after 1000 rounds
mac 10 9mm some leading after 1000 rounds
mac 11 .380 some leading after 1000 rounds
uzi 9mm depends on the barrel that i have in it some lead some do not 1000 rounds
sten 9mm moderate leading but the bore is not the best 1000 rounds
mk 760 9mm moderate leading 1000 rounds

i do 2 mag dumps spaced between 5 mags that are fired in 3 to 5 round bursts giving the gun time to cool off between mags, ok sometimes i do 2 mags back to back
and do not shoot cast bullets through a suppressor as they will fill it up full of lead carbon and bullet lube same as the cutts comp of my thompson

chris in va
03-26-2014, 12:47 AM
Probably should look into moly or powder coating.

fastfire
03-26-2014, 01:01 AM
Powder coat, NO leading and will be able to use the suppressor.


Probably should look into moly or powder coating.

gmsharps
03-26-2014, 03:19 AM
So why do you think the 200gr leads less than 230? Currently I have 1,000 230gr projectiles resized sitting in a bin I was about to load tomorrow to see how they do. What kind of harness are you running?

I did not mean they lead less but just that they weigh less and use less lead. The 230gr bullets will work just fine also. I usually have quanitys of the 200gr bullets available as I favor them in my 1911's so I use what I have. I'll get around to casting a bunch of 230's one of these days and I may use them as well. The M1A1 only uses stick mags so 20 or 30rd sticks keep me from burning through to much ammo at once. Sorry for the confusion.

gmsharps

Pyrex
03-26-2014, 09:54 AM
cast bullets in pistol caliber machine guns is not a problem just follow the standard procedures for size and lube
i shoot them in
1928 thompson 45acp just have to keep cleaning out the cutts comp as it tends to build up with carbon and lead very minor leading in bore 1000rds
mp40 9mm those Nazis made good barrels no leading after 1000 rounds
mac 10 9mm some leading after 1000 rounds
mac 11 .380 some leading after 1000 rounds
uzi 9mm depends on the barrel that i have in it some lead some do not 1000 rounds
sten 9mm moderate leading but the bore is not the best 1000 rounds
mk 760 9mm moderate leading 1000 rounds

i do 2 mag dumps spaced between 5 mags that are fired in 3 to 5 round bursts giving the gun time to cool off between mags, ok sometimes i do 2 mags back to back
and do not shoot cast bullets through a suppressor as they will fill it up full of lead carbon and bullet lube same as the cutts comp of my thompson

I went ahead and bought a serviceable can so I can shoot suppressed cast. The gun is an AR15 that I'm using modified greasegun mags. 10.5" barrel. Good to hear you've had good results!

nhrifle
03-26-2014, 11:45 AM
Mike Venturino did a writeup in Shooting Times magazine awhile ago, interesting reading. You may want to get in touch with him and find out what worked and what didn't.

Pyrex
03-26-2014, 11:50 AM
Mike Venturino did a writeup in Shooting Times magazine awhile ago, interesting reading. You may want to get in touch with him and find out what worked and what didn't.

How long ago was this? I did search the forum first and found a post in regards to an old article many years ago, but no one could find it.

nhrifle
03-26-2014, 12:24 PM
My bad, I think the article was actually in GUNS magazine. I am out of time to search the archives as I have to go to work, but will look later.

Pb2au
03-26-2014, 01:15 PM
I currently help "feed" a friend's M-10. I use the Lee 230 RN boolit with Lyman's super moly lube and have had no problems in it. Surprisingly, I slugged the barrel it was spot on 0.451". I currently size them to .452" and function is fine. He has opted not to use them when he has the suppressor mounted. It is of an older design and is pain to clean.

Pyrex
03-26-2014, 09:58 PM
If anyone could locate that article I would love to read it. I've been chasing it for a few years.

tiger762
03-29-2014, 10:08 PM
I have M10/9, M11/9, M11/380 and M10/45, all full-auto and suppressed. I have put craploads of cast wheel weight hollow points (http://www.mp-molds.com/). I would just make sure they are 0.001" bigger than bore diameter.


cast bullets in pistol caliber machine guns is not a problem just follow the standard procedures for size and lube

btreanor
03-31-2014, 11:24 AM
In addition to making sure that you use good lube and have a good boolit fit, load every fifth round with one that has a jacketed bullet. This will help prevent lead build-up.