Last night I got two steel cased shells stuck in the chamber after the gun got very hot.

I was shooting BCM 11.5" w/ Turbo K and after 2 or 3 full mags shot very quickly, I'd get a shell stuck in the chamber.

It was Tula steel cased.

My understanding is that this isn't unexpected, but what exactly is happening?  Is the chamber heating up and expanding?  Or is the steel case expanding too much?

Just trying to understand.

Thanks

The steel cases don't expand to seal the chamber like brass does so you can get carbon buildup in the chamber that could cause cases to stick

Yep, first course of action is clean that chamber really well.

Suppressor is going to make it worse.

That's it!  I thought it was something like that

It seems to run fine when not super hot, but then it get's hot and I get a stuck one.  

Need to just get rid of all this steel cased ammo I got, seems like Tula is the worst of it.

Generally, stuck cases are the result of poor metallurgy of the case.  It can happen to brass, but brass is more forgiving than steel.

I had understood that both brass and steel expanded when shot, but the Brass being more "elastic" would come back close to its original shape.

This needs to be done with a fairly new chamber brush, a worn one will not get it done.  I had to put mine in a power drill to get all of the crap out and it took three goes at it.

I immediately sold my stash of 5 cases of poly/Wolf.  Never again.

I think it's the poor quality of the Russian powder that causes the excess carbon and stuck cases myself.

Because I reloaded about 1,000 steel .223 cases back when they came in with Boxer style primers.

Sizing was almost as easy as with a brass case and they were short enough to not need trimming.

I wet tumbled them and dried them well before loading.

The polymer coating took on a very shiny almost glass sheen and the cases appeared dark gray.

I fired about 600 rounds of those suppressed and full auto and never had 1 single issue.

The cases looked almost perfect upon ejection with none of the typical soot and carbon residue found on them from their factory load being fired.

Some AR’s will stick steel case no matter what you do.

I own two that stick cases every time. Mine run brass with no trouble at all.

A steel-case 5.56 advocate will be along shortly to admonish you for the “low quality” of your barrel and/or instruct you on your deficient cleaning methods.

Nope. Just shoot it more, it will stop all on it's own once the chamber sees more wear. I had a Windham Weaponry that did the same within the first 500 rounds, but have been shooting everything through it since then and never had another failure.

Imagine having to rod-out 500 stuck cases to “season” a barrel to shoot steel-case.

I thought alot of steel had a coating to prevent oxidation. In turn that coating gums things up fast requiring more frequent cleaning... Thoughts?

I got 1,662 rounds through it, only ever gets stuck when it's super hot.  

No no no no no. I only rodded out one case and mortared out another in the first 500 rounds, none since. If I would have had to rod out many more than that it would have gone in the trash.

That was the original theory.  It's not really correct.

Current consensus is it's a combination of steel swell and poor sealing properties that allowing powder residue to sneak back into the chamber (gaskets are rarely made out of steel, probably for a reason),  lower general adherence to the deposition so not really pulling much out with each shot (and so the fouling builds up).  Those two combined means a lot of sticky foulant building up and staying built up with steel.  Add in how steel doesn't have a spring-back, but stays swollen to full chamber (and chamber imperfections) dimensions.  


And on that note, beware when switching back to brass, which has a greater affinity to the build up, and can stick badly when done after many steel rounds.

When I shoot steel (rarely, but I do run steel in Grendel, as it was purchased for 25 cents a shot);  I always finish the session with a few brass rounds to "clean" the chamber.

Every steel round I put in the two uppers stuck.

Every. Single. Round.

Ripped every rim off.

One upper was a 20” Armalite. Other was a 10.5” JT Enterprise.

Two types WOLF steel case. One with lacquer coating. Other was polymer coating.

After three or four back-to-back insertions of the cleaning rod, the rod was too hot to touch.

I blasted half the remainder of that (large amount) of WOLF through a 5.56 AK on other dates until I got tired of it. I sold the 5.56 AK, and gave-away the rest of that godforsaken batch of steel-case 5.56

could be rough chamber?

Just a follow up, I scrubbed the chamber really good.  I used one of those Real Avid Chamber tool thingys.

Went to the range last night and shot 140 rounds of brass then 90 rounds of steel.  

Not a single hiccup.

Ain't that what I said?

I thought the lacquer coating on some of the cheap steel-case ammo causes a sticky build-up in the chamber.  needs to be vigorously cleaned out with a strong cleaner and chamber brush.

strong cleaner is the kind that causes cancer in Kalifornia.

It's the steel, not the coating.

Steel cases, combined with dirty powders in Russian ammo.  I’ve had this happen, and have seen this happen on several DI AR15, piston AR15 and a Tavor.  Everyone has heard the whole thing about “if your rifle doesn’t run steel, then it’s a crap rifle”, but there’s a reason why you don’t hear it happen with brass nearly as often.  Having to scrub the chamber every couple of hundred rounds is a waste of my time.  Having to use a rod to knock out stuck cases with ripped off rims is a waste of my time.  Only shooting a few rounds to prevent heat, to minimize the chances of a stuck round is a waste of my time.  On top of that, Tula chronos at lower velocity and shoots less accurately than even the cheapest brass case ammo, which means that even if it runs in your gun, it’s only good for 50 yards and under training and plinking.  Personally, I don’t use steel case ammo in .223/5.56 guns.

I did run Tula/Wolf/Barnaul in 7.62x39 guns, when I had those, but the more aggressive taper of that cartridge contributes to it’s extraction, and I wasn’t worried about hitting anything past 200 yards with any of them.  I still use steel case 7.62x54R in bolt guns and 9mm in blowback PCCs.