Cast in a machine gun?

[Pb2au]

Specifically, a Mac-10, mounted with a suppressor.
A good friend of mine owns one of these guns in 45 ACP, and he and I were talking about the concept of running cast boolits in it. Now, having absolutely no point of reference to consider, I am coming here for perhaps a bit of direction.
I have my reservations about the idea.
1) I can imagine the mechanical performance of a cast boolit in a full auto gun would be different that a semi auto. Specifically, I have no idea how the accumulated heat in the barrel will impact the performance of the lube, and even the how it might impact the alloy of the boolit itself.
2) The quality control of the final finished rounds will have to be perfect. Specifically, the extremely unlikely event of a squib. It could absolutely wreck the operator and gun. I like many others do a visual inspection of the dropped charge before seating the projectile, but in this case, it would in my opinion require at least another quality check. My thought would be weighing the finished loaded rounds to look for missed charges. This of course would require sorting cases into like weights to understand deviations in weights.
3) of course the usual boolit fit to barrel, slugging, etc ,etc. The normal stuff.
4) I have no idea if there are any considerations to running boolits through a suppressor. My only thought would be lube fouling it, but again, I have no idea.

So, I am wondering if anyone has any experience in this arena. Right now, I told him that this will stay in the theoretical phase until I can get my mind wrapped around it. After that, I might, maybe, possibly, consider it.

Many thanks team,

[freebullet]

I bet it could be made to work, but those guns are $$$$. 45 is slow enough for plated bullets.

[lancem]

I have shot thousands of cast through my 9mm AR with slidefire stock, sure not a true FA but the rounds are going down range one right after the other. No leading problems over what I would expect with a thousand rounds shot between cleanings (hard to stop once you start, dang things fun). I doubt a squib load would cycle the action, so a cycle failure would be an operator responsibility to check why. I'm sure that the suppressor would have to be cleaned more regularly than if FMJ ammunition was being use, this is something that I think would have to be found out by shooting and determining as you go along. My opinion would be go for it, in my experience I don't see a down side.

[crawfobj]

Mike Venturino has several Handloader articles about casting to feed his various sub guns. Sounds like that's basically all he shoots in them. I see no reason not to, unless that can can't be disassembled for cleaning.

[MAUSERMANK98]

I have done this when I had one and was using unique powder. working pretty good but a had a barrel extension on the gun and built up some lead in threads where it screwed on to gun. barrel was clean enough but took a while to get lead off of threads on front. Think we were loading standard load in lyman book for the 225 rn bullet. PLUS we were on dipping the bullets for lube not sizing and lube with a tool. think it would have worked much better if we would have done that extra step.

[Char-Gar]

I have fired cast bullets in a full auto Thompson (45 ACP) and a full auto UZI (9mm) with good results each time. Subguns strip the round from the mag and shove it straight into the chamber with no ramp to negotiate. As long at the gun is sufficiently clean, properly lubricated, set up properly and fed ammo within the right pressure range for good function, there is no problem with cast bullets. But these same caveats apply to jacketed bullets as well.

The suppressor may prove problematic, but I don't know from experience.

[MattOrgan]

When I had access to a Thompson SMG I loaded a lot of .45 ACP with cast. Never an issue with function, accuracy, or leading. The only caution I heard was not to mix jacketed with cast in the same magazine because it could cause chamber/barrel ringing. Not sure how that would happen, but the person who told me this always knew what he was talking about so I followed his advice.

[NoZombies]

I shoot my machine-gun exclusively with cast bullets. As long as the suppressor that your friend plans to use is serviceable, there should be no problem at all. Mac 10's wok well with cast bullets according to my friends who own them.

Here's some video of my .45 MG running with cast:

http://youtu.be/pcrsxCVl_rc

[Larry Gibson]

I've fired a lot of rounds of cast bullets loads full auto through numerous .380, 9mm and 45 cal MAC 10s and 11s. Some with suppressors. No special care needed to be taken in loading specific to those guns other than having a bullet profile that fed and sufficient power to function the action. Most were fired with standard pistol loads that were loaded on progressive presses with home cast or commercial cast bullets. The suppressors did need more frequent cleaning due to lube and lead build up that with jacketed bullets.

However, with a high powdered CF rifle cartridge using a suppressor I do not fire cast because the lube is spun off and can quickly gum up the suppressor. If you've one that can be readily taken apart and cleaned it is ok but with my Sionics I no longer shoot cast through it. If I do it has to be dismounted from the rifle and boiled out which is a pain.

Larry Gibson

[Pb2au]

This is excellent information gentleman. I love that we have much real world experience to draw from.
The bullet profile in Lee's 228 grain round nose, so I am thinking that should have no issues feeding. My pet load for that is pretty standard, 6 grains of Unique, so I believe function should be good.
I have not laid hands on the suppressor, so I do not know if is of a design that makes it possible to break down to clean. I will question my friend.
We will proceed with some function testing. This should be an interesting experiment.

[smkummer]

I went to Lee's 230 TL bullet because of the 6 cavity mold. Works out of a Reising, 1928A1 Thompson, Stemple and US M3 grease gun. But the compensators of the reising and Thompson have alot of build-up of lead including the grease gun's cone shaped flash hider. And that is even with spraying compensator spray (a product that is supposed to not allow fouling and lead to build up). I don't own a suppressor yet but it better be able to come apart easy for cleaning and I would try only a magazine or 2 before breaking it down to see how easy it would be to clean. Again, this is from what I am seeing in my compensators. let us know how it goes.

[williamwaco]

I have done it.

The only problem is that you can only use once fired cases and you cannot reload them.

It bulges the cases at the head - severely.

You can resize them and fire them in a 1911 with a fully supported case but if any part of that resized bulge is aligned with the cutout in the chamber when you fire it in the MAC 10, it will burst.

I got rid of it.

[NoZombies]

I have done it.

The only problem is that you can only use once fired cases and you cannot reload them.

It bulges the cases at the head - severely.

You can resize them and fire them in a 1911 with a fully supported case but if any part of that resized bulge is aligned with the cutout in the chamber when you fire it in the MAC 10, it will burst.

I got rid of it.

Sounds like you had a bad barrel. I've never heard of anyone else having the problems that you've described.

[Japlmg]

My son owns a MAC-10 in 45 ACP.
He shoots my cast bullet reloads in it all the time, with out any issues.
I use a 230 cast round nose, flat base bullet, I buy from a commercial caster in the area, Space Coast Bullets.
My powder charge is 5 grains of Red Dot, and use any standard large pistol primers I can get (mostly Wolf and Winchester).
Gregg

[Herb in Pa]

I've shot thousands of rounds using cast bullets in my MP40 without any problems. Most subguns fire from an open bolt and will leave a bulge in the case. If you're just shooting these in the subgun there isn't a problem. To use these cases in other 9mms one can obtain a sizing die that will resize down to the cartridge head. I would be reluctant to fire cast through a suppressor, I have a full auto rated SWR Trident suppressor and it's only seen full metal jacketed rounds. It seems to me to be a false economy to fire cheaper cast slugs and potentially screw up an expensive suppressor, sort of like running recaps on a Ferrari..........just my thoughts.

[jmorris]

I too run cast FA, makes smoke and leads the barrel but is cheap and works. I try and not use a suppressor with cast and have one less thing to clean.

A case pro machine is the best thing to bring cases back to factory dimentions after being fired in SMG's.

[RoyEllis]

If it wasn't for cast, I couldn't afford to feed my wife's choice for a "nightstand gun", Cobray M-10 9mm select fire. Guess it's digested well over 150K lead RN reloads, usually takes 25 or so 36rnd mags before her hands hurt enough to set it down, but it really amuses her & the grandkids. Suppose it is kinda funny to watch "Granny" get worked up while ventilating a rogue appliance.

[Herb in Pa]

if it wasn't for cast, i couldn't afford to feed my wife's choice for a "nightstand gun", cobray m-10 9mm select fire. Guess it's digested well over 150k lead rn reloads, usually takes 25 or so 36rnd mags before her hands hurt enough to set it down, but it really amuses her & the grandkids. Suppose it is kinda funny to watch "granny" get worked up while ventilating a rogue appliance.

grambo..............

[inspector_17]

Would powder coat fix the problem? Seen results for powder coating here, great looking bullets. But what about the cost?

[Larry Gibson]

Sounds like you had a bad barrel. I've never heard of anyone else having the problems that you've described.

I never had that problem either.

Larry Gibson

[jmorris]

Would powder coat fix the problem? Seen results for powder coating here, great looking bullets. But what about the cost?


The hi-tek coating works. Less labor and cost vs PC.

[jmort]

"Less labor and cost vs PC"

Possibly less labor but for sure, not less cost.

[Pb2au]

So we ran the M-10 with boolits yesterday and all was well.
We did not use the suppressor with those loads however. The owner was a little hesitant, and seeing as it is his machine gun I did not protest. But, the boolits performed fine with really nice accuracy to boot. No leading in the gun. All in all, cheap shooting and a heck of a lot of fun!
The cases I recovered looked like any I might get from my kimber, so from that I guess the chamber does a reasonable job of supporting the case. I will put them under the microscope in the bat cave tonight.

[Smoke4320]

I have shot many many 45 ACP pc'ed bullets thru my Kriss Super V FA and YHM suppressor .. no issues at all

[303Guy]

The question of squib loads hasn't been addressed yet. Should a squib load occur (and I assume the question was about a boolit being left lodged in the barrel), could the action cycle and fire another round?

[Pb2au]

303Guy,

My guess in this case would be no. The bolt of the M-10 is incredibly heavy. I had no idea how massive it was until I was able to hold the firearm. But, that is a guess, and we all know what that can be worth.
The idea of a squib was really preying on me going into this adventure. I did an audit of the ammo I loaded for it. Besides the usual visual inspection of the charge during the loading phase, I sorted the finished cartridges by head stamp and weighed them to hopefully find any very low weights in the lot.
But once the owner stripped the weapon and educated me on its mysteries, I felt pretty confident that it should "fail safe". Another person posted here, correctly so, that even though it is a machine gun, the same range safety rules apply.
But again, read guess.

[43PU]

I have a Yankee hill can on a reising and they told me to "lube" the first 2 baffles with Vaseline... I would imagine the bullet lube does the same thing... It smokes a lot but that's what they said is best for their cans.. My 36 black powder smokes less.
However the only cast I have has problems with is my 1945 STG-44 it is a pain mostly because the barrel has "loose" spots in it when you slug it. My Soumi does great with cast in SA and FA and I dump 72 end mags all the time

[NoZombies]

I have a Yankee hill can on a reising and they told me to "lube" the first 2 baffles with Vaseline...

Would you be willing to post a picture or two of the set up? I've been trying to find a machinist to make me a replacement barrel for the Reising that would allow me to run a suppressor.

I assume the YHM can is user serviceable? Which model is it? How's the performance?

[Artful]

I think you'll find Never Seizes works well to keep from coating things permanently, It's what I use on my user serviceable cans.

[Silence is golden]

My best 9mm load consists of a LEE TL.358-158-SWC lubed with LLA sized to .356 on top of 3.0 grs. Of bullseye with a coal of 1.020 velocity is 869fps out of a Glock 18 FA SBR it made that G18 run like a scalded cat

[jimb16]

I used to have a registered M2 carbine and fired cast through it all the time. Just remember to keep the rate of fire reasonable so you don't get the barrel too hot. I lit the handguard once from too many 30 round mags in too short a time! *LOL*

[dogrunner]

Had an MP40 for many years..........'68 amnesty registered piece. Shot truncated cone Lachmiller 120's almost exclusively in that gun. Still have my M1A1 converted to full and have shot the Lyman 311359 thru it almost exclusively since '66. Load for the latter is about 12.0 of 2400 nowadays as opposed to the heavier loads recommended back then, the 40 load consisted of the mentioned bullet and 5 gr's Unique. I cannot recall a malfunction in that 40, ever!

The Carbine tho takes some attention to detail and after the cases get some 'life' on them.....harden, get 'springy' and won't hold a bullet well.....course most of my brass dates from the 50's so.................!

Anyway, cast in a full auto is no more of a problem than in a bolt gun, provided you pay close attention to your lubing. Have a buddy that used to run cast in an 08/15 with great results and reasonable accuracy....you do want to avoid really heating the bbl tho.

Far as the mention of 'bulged' cases in another poster's '40 goes I'd amost bet that it was not loading or technique. My '40, a nearly mint speciman, had a chamber unlike any I've ever seen, and it was obviously deliberate, the forward portion of that guns chamber was recessed for at least 3/4ths of the case length prior to the rifling lead.....I surmised that the chamber cut was a method of delaying blowback.........anyone else ever seen this? Kinda the reverse of the HK fluted chambers I guess.