Steel Ammuntion? In my AR?

[T2C]

I fired 400 rounds of lacquer coated steel case 55g Wolf ammunition today without a malfunction. That's 1,200 rounds in the past two weeks and makes a total of 800 rounds of lacquer coated ammunition fired since the last cleaning without a failure.

Does this mean that certain AR-15s cannot tolerate steel case ammunition, but others can?

[wildcard600]

I fired 400 rounds of lacquer coated steel case 55g Wolf ammunition today without a malfunction. That's 1,200 rounds in the past two weeks and makes a total of 800 rounds of lacquer coated ammunition fired since the last cleaning without a failure.

Does this mean that certain AR-15s cannot tolerate steel case ammunition, but others can?

My BCM's have never given me an issue with steel case ammo. I have a PSA upper that I threw on a beater lower to have around when i'm brush mowing the back fields that continually choked on steel cased. So, after chasing my tail around for a while I said "screw it" and put some soft scrub on a shotgun mop and "polished" the chamber a bit with it. What came out was a mess of sticky brown crap that reminded me of cosmoline. I repeated this until the mop came out clean and now that upper eats steel cased like a BCM.

I don't know what the brown crap was, but i suspect it was some kind of protective coating applied after the barrel was manufactured. I would recommend to anyone who is having issues with steel cased to clean your chamber really well.

[bighawk]

I have a few thousand rounds through my DD MK18 this summer (all suppressed) without a single issue.. All my steel ammo is .223 62gr Wolf Military Classic and WPA manufactured at the Barnaul plant.

While it is obviously not precision ammo it is fairly accurate out to 200 yards as well.

[OTShooter]

Actually, steel cases obturate just fine.

I had surmised that steel didn't obturate as fast because the sooty deposits seem to only be in the neck area of most people's chambers, and because of the particular "sound" steel cartridges make: they do not "ring" like brass, but rather "thunk." To me the latter indicated a very different elasticity profile, which would go along with the case neck not expanding at the same rate as a brass neck.

Is the very tiny delay you mentioned long enough for some gas to "float" the neck? Since even the filthiest brass-cased 5.56 I've shot (generally Winchester) does not leave the kind of case neck deposits I've seen with "good" steel-cased (Barnaul) ammunition. There's got to be some specific mechanism that causes this difference, even if it isn't as likely the cause of stuck cases.

Oh yeah, to the individual who dissed "cheap decisions," I agree with the other guy who says "more shooting is always better." I don't expect much in terms of precision from any bulk ammunition, and I don't depend on steel cased Russian ammo for anything but trigger time. But more shooting is always better.

[lysander]

I had surmised that steel didn't obturate as fast because the sooty deposits seem to only be in the neck area of most people's chambers, and because of the particular "sound" steel cartridges make: they do not "ring" like brass, but rather "thunk." To me the latter indicated a very different elasticity profile, which would go along with the case neck not expanding at the same rate as a brass neck.

Is the very tiny delay you mentioned long enough for some gas to "float" the neck? Since even the filthiest brass-cased 5.56 I've shot (generally Winchester) does not leave the kind of case neck deposits I've seen with "good" steel-cased (Barnaul) ammunition. There's got to be some specific mechanism that causes this difference, even if it isn't as likely the cause of stuck cases.

Oh yeah, to the individual who dissed "cheap decisions," I agree with the other guy who says "more shooting is always better." I don't expect much in terms of precision from any bulk ammunition, and I don't depend on steel cased Russian ammo for anything but trigger time. But more shooting is always better.

From examining the last 100 or so rounds from a single lot of Tula I have shot, I did not see abnormal sooting of the case neck, it wasn't much worse than some of my reloads.

I would like to see some steel cased ammunition loaded with a known clean propellant, or at least the same exact propellant loaded into steel and brass and the results compared.

Maybe an experiment is in order . . .

[Alex V]

At classes I should steel cases Wolf almost exclusively. It's $100/case cheaper than brass. In three cases I have paid for a new barrel and anything over that I am ahead of the game. Seems like a no brainier to me.

[bighawk]

At classes I should steel cases Wolf almost exclusively. It's $100/case cheaper than brass. In three cases I have paid for a new barrel and anything over that I am ahead of the game. Seems like a no brainier to me.

This is my thought process as well.

I am actually about to purchase a new 10.3 barrel for my MK18 this week so I'll have an extra sitting around if/when I actually wear mine out.


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[sasquatchoslav]

This is my thought process as well.

I am actually about to purchase a new 10.3 barrel for my MK18 this week so I'll have an extra sitting around if/when I actually wear mine out.


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I think you will be shocked at when that barrel swap needs to happen. I have an old Colt that went over to a diet of steel maybe ~ 99-00. Still my go to. With the volume our family shoots it's not barrels we could afford it's entirely new rifles at this point.

[nova3930]

Since I shoot behind my house out in the field mostly these days I've nearly switched 100% to shooting polymer steel wolf. That eliminates my reloaders OCD that causes me to try to find every single solitary brass case.....

Actually, steel cases obturate just fine.

At 50,000 psi the sides of a steel case are stuck against the chamber walls as well as any brass case. The difference is at what pressure the case fully expands to achieve the seal.

The bullet uncorks from the case neck when the pressure inside the case is about 900 psi, brass or steel. As soon as it uncorks, gas will start to flow around the case into the chamber bringing all the dirty combustion products with it. How fast the case neck inflates to seal this flow off depends on a number of things, but mainly, 1) how fast is the pressure rise inside the case, and 2) how resistant is the case neck is to distortion.

Stuck cases are probably far more likely caused by improper heat treatment of the steel. Otherwise all steel ammunition would start to show FTE after a certain number of rounds, which is not the case, they tend to occur at random.

As to lacquer causing problems, all US produced steel cased ammunition, mainly 25mm, uses lacquer as a corrosion preventative. However, and this is a big however, 25mm product testing has shown that the wrong choice of lacquer will cause problems. Is it out side the realm of possibility that some lots of Russian ammo where made with a poor choice of lacquer? No, I don't think so. But again, it's the generalization that is wrong - lacquer = bad, no, more correctly it's poor quality control = bad . . .

As to the alloy used, almost everybody that has ever made cases from steel has used a mild steel alloy, 1025 or 1035, maybe 1040 or the local equivalent. One, it's cheap, and that was the whole point of steel cases in the first place. And two, it has a strength similar to cartridge brass. Many people think that steel cases are much stronger than brass, they are a tad stronger at the rim, but not really enough to really make much difference.

And, here is where we are going to refer back to the obturation thing. The neck of a brass case is fully annealed (or it should be) so the the yield strength is 45,000 to 60,000 psi. Any guesses to the yield strength of 1035 tempered to about HRb 60 to 70 (what Frankford found to work best)? Yeah, it's around 40,000 to 50,000 psi.

The resistance of the case neck to distortion is about the same for brass and steel cases, so they obturate just as well and, for the same pressure curves, just as fast. The reason Russian cases are dirtier on the outside is the probably due to the propellant they use.

There has been a big change in Russian produced ammunition that has changed the whole barrel wear thing, however. They, at least Tula, have stopped cladding the jacket with gilding metal. It might make a significant difference with .224 bullets. Generally, the cladding was .003" thick, which is about the same as the depth of the lands. The cladding did provide some lubricity similar to regular GM jacketed bullets.

Outstanding info.

[lysander]

From examining the last 100 or so rounds from a single lot of Tula I have shot, I did not see abnormal sooting of the case neck, it wasn't much worse than some of my reloads.

I would like to see some steel cased ammunition loaded with a known clean propellant, or at least the same exact propellant loaded into steel and brass and the results compared.

Maybe an experiment is in order . . .

Well, I decided I would test this theory, and pulled five Tula bullets and replaced the propellant with 24.5 grains of benchmark, and loaded five rounds in brass cases with the same load.

Full report later.