Why no steel-cased ammo?

[Skarekrow88]

Just got my Numrich made 1927A1 back from tommygunner. It was handed down to me from my grandfather and was missing the bolt assembly. I am itching to shoot it but I have read that it is not recommended to run steel-cased ammo throught it and unfortunately steel-cased ammo is all I have...Why is it that running steel-cased ammo through a Thompson is a bad idea?

[CTS]

That is a good question that I wish I could anwer. I am curious as to where you found any steel cased .45ACP? I have never seen it.

[Dc777]

Sloppy- I've bought a bunch of steel cased .45acp from Walmart. It has been Tula. Surprisingly my guns eat it up.

[Metal god]

That sounds like a tough question to be answered . There's just not a lot of people left that shoot those any more .

This is me just thinking out load and throwing some stuff out there

Just a guess : Older metal when made may wear more then modern metals I.E. chamber , extractor . I'm not sure how the Thompson operates but if the case needs to expand and seal the chamber . Steel cases don't have as much elasticity as brass and with a such a short case you may get blow back outside of the chamber do to the case not expanding and sealing the chamber .

[seeker_two]

Maybe the steel-cased ammo they're referring to is the old WWII stuff? The Russian ammo is better quality than that.

Try a mag or two. If you don't have any problems, enjoy!

[44 AMP]

original US steel cased .45ACP ammo was only made in one year, 1943. Even during the height of land combat in WWII, with brass in demand for so many other things, we went back to brass cases for the .45 after one year of producing steel (and I've never seen any steel cased ammo that wasn't EC 43 headstamped, so I believe it was all done in one place).

The only issue I have had in over a decade with my Tommygun was a broken extractor. I don't shoot steel cased ammo, ever.

You have a fine gun, but if you feed it the cheapest crap you can get, expect issues. If you don't get them, consider yourself blessed.

[bcarver]

steel does not expand and contract like brass. There could be a lot of gases going around the cases and cases pulling steel against steel on extraction rather than the softer brass.

[Metal god]

You have a fine gun, but if you feed it the cheapest crap you can get, expect issues.

^^^yep^^^

Handed down from his grandfather . Heck yeah , thats one of the good ones and I'd do nothing to screw that thing up .

[CTS]

The only thing I can think of is since the Thompson works on blowback design, that too much pressure may escape around the case and not have enough left to cycle the action since the steel cases don't expand the way brass does and will not seal off the chamber. Although I have shot plenty of it in ARs with no problem but then ARs are not blowback operated and are generally overgassed anyway.
I have seen plenty of .223/5.56, 7.62x39 but was surprised to hear they were making it in .45 ACP. I have never seen it but then I reload most of my .45 ammo so am rarely in the market for store bought.

[tahunua001]

I think somebody is pulling your leg. M1911 ammo was steelcased and a heckuva lot of that went through tommies. I've personally seen a number of different headstamps and years on the steel headstamps.

[CTS]

I think somebody is pulling your leg. M1911 ammo was steelcased and a heckuva lot of that went through tommies. I've personally seen a number of different headstamps and years on the steel headstamps.

I'm not sure about that. I carried a 1911A1 in the military for quite a few years and never saw any steel cased ammo being used. It may have been made for one year like was mentioned earlier but the majority of it was brass cased. I am not one of those who think that steel cases are crap. I have shot plenty of it but obviously some companies warn against it otherwise the OP wouldn't have started the thread. Kimber says that it is fine as long as your gun is clean and lubed properly. http://forums.1911forum.com/showthread.php?t=133427

[Dfariswheel]

The problem is, steel cases aren't as elastic as brass, and won't expand and contract back like brass will.

This lower elasticity of steel cases prevent the lower pressure pistol cases to expand enough to fully seal the chamber and that allows fouling to escape into the chamber and foul it.
In addition the steel cases don't contract back to near original size and are normally harder to extract from the more straight walled .45ACP chamber.
The combination of chamber fouling and less contraction of the case causes harder extraction.

Auto Ordnance discovered that steel cased ammo's harder extraction causes much more stress on the extractor and will cause extractors to break.
For that reason they specifically state that steel cased ammo is not to be used in the semi-auto Thompson guns.
If you do shoot steel ammo, you can expect broken extractors and that will not be covered under the warranty.

[James K]

WWII steel case .45 ammo was not taken out of production because of any problems with the ammo itself, but because it was hard on the production equipment and the copper supply improved to the point where steel was no longer needed.

FWIW, the U.S. also experimented with rifle and carbine steel cased ammo but only the .30 Carbine was ever produced in volume. Drawing problems with steel case .30-'06 ammo were never solved before the end of the war, in spite of the fact that Germany had been able to produce billions of rounds of steel-cased 7.9 ammo.

(I once talked with a man who had inventoried a captured German ammo depot. It held over 5 million rounds of 1944-dated 7.9 brass case ammo that had been rejected by the Luftwaffe as not up to specifications and was awaiting issue to the ground forces. That didn't happen; it was eventually destroyed.)

Jim

[Skarekrow88]

Thanks for all of the feedback. Just to clarify the steel-cased 45 ammo I have is manufactured by Tulammo. I guess it's better to be safe than sorry. I suppose I will just shoot the steel-cased ammo out of my .45 pistols and buy some brass to run through my Thompson. Would Blazers aluminum-cased ammo be an alternative?

[CTS]

Blazer should be fine. It is no harder than brass on an extractor as far as I know.

[swopjan]

WWII steel case .45 ammo was not taken out of production because of any problems with the ammo itself, but because it was hard on the production equipment and the copper supply improved to the point where steel was no longer needed.

What does copper have to do with steel cases? Is that a typo or am I about to learn something?

[44 AMP]

What does copper have to do with steel cases? Is that a typo or am I about to learn something?

Copper doesn't have to do with steel, it has to do with brass.

We made steel case .45 ammo in WWII to allow brass to be used for "more important" things. Improved copper production improved the brass supply, and we went back to brass .45 cases. Now, considering that everyone says steel cased ammo is cheaper than brass, it seems to me that there must have been some other reason we went back to the more expensive brass ammo, what with a war on, and all...

[swopjan]

I see, I did not know that copper was one of the elements in brass. Thanks

[Opinated]

http://en.wikipedia.org/wiki/Brass
Hope this helps.

There was a time when none of us knew about brass.
My experience with the steel-cased ammo has been good.

[Art Eatman]

Then learn about bronze:

http://en.wikipedia.org/wiki/Bronze

TFLers get smarter all the time.

[velocette]

I work at a large municipal firing range. Of all the problems with firearms we see, by far the most common is steel cased ammo sticking in the chamber of a rifle. Most common with ARs but also seen with bolt rifles. The higher the quality of the rifle, the worse the problem is. Our stainless steel bore rod is very frequently in action as brass cased ammo is hard to find. You may rest assured that steel cased ammo is never & will never be used in my rifles.
Incidentally, to my knowledge, we've never had an AK type rifle jam up with steel cased ammo.

[HoosierDave1967]

I am by no means an expert, especially when it comes to the debate regarding the elastic natures of steel vs. brass or which is better for a particular firearm. I think most of these issues come down to cost per round, casual vs. competitive shooter and other circumstances.

However, I will state that here in Central Indiana, if you do not have a private place to shoot, either your own property or that of a friend, good luck finding a public or semi-public range that will let you shoot steel cased rounds, of any caliber.

As to why, I have no idea. I purchase target/practice ammo from reman companies and the cost is the same per round compared to TULO and other steel cased ammo, so I have never immersed myself into the why.

[PVL]

Since re-barreling a Thompson is no trivial matter, I wouldn't recommend running steel cased ammo through it.

It will scratch and wallow out your chamber, most particularly after the gun gets hot from firing a little.

The cold steel on the case mouth will be harder than the hot steel of the chamber, and damage will follow.

Sure, they police departments fifty years ago used to shoot steel-cased ammo through their Thompsons... They could get new barrels pretty easily back then and on top of that, they were spending other people's (tax) money, so fiscal responsibility was not what you would call a top priority.

Just as it is with law enforcement today.

Price new replacement Thompson barrels ( if you can find one ) and the fee to have a new one put on - and then make a decision about running steel-cased ammo through your gun.

[mete]

Brass used for cases is "cartridge brass" which contains 70 % Copper and 30% zinc.
Steel that is as soft as they want is difficult to make ! Much of it is harder than wanted so the wear and tear on production machines is high and the same for firearms.
The world always comes down to METALLURGY !!

[HiBC]

My 2 cents.
Most older barrel steel is not very hard.Its more free machining for good surface finish from the barrel making tools.It does not get heat treated after rifling/chambering,so its still pretty soft.

The steel of the "brass" can only be so much softer than the barrel steel.As a 45 headspaces on the case mouth,a heavy blowback bolt slamming a steel case mouth into the headspacing chamber mouth sounds destructive.

One more thing,Peak pressure case obturation (brass case) grips the chamber wall and delays the bolt blowback.See Ackley's experiments removing locking bars from a Win 94.

A steel case might allow the bolt to blow back when pressure is higher,so the rearward bolt velocity may be higher.

Hoosier Dave,Many ranges will not permit any bullets that will stick to a magnet.With the bullet,steel can make sparks as it hits rocks,and fires can result.(OK,it is controversial,some say it can't happen..).but that is the reason for steel bullets.Cases?No clue,unless it has to do with recycling the brass and contamination.