Learning every week: ammo and ammo

[amafrank]

Steel does wear the extractor faster than brass.

I keep wondering where this idea comes from. The only real difference between steel and brass cases in use is that the steel tends to spring back faster which means as the pressure drops in the bore the steel relaxes its grip on the chamber sooner. Less grip means less energy required to pull the case from the chamber. Since most firearms don't pull the case from the chamber, it pushes the bolt back through residual pressure, that isn't even an issue. Look at the number of small handguns and rifles with no extractors....Beretta 950s come immediately to mind. The case pushes the slide back, the extractor doesn't pull the case out. This is true of your 1911 and most other semi auto firearms too.

Every steel case I've seen in commercial or military use has a coating which is softer than brass by far. Laquer was popular, copper or other metallic plating, polymer coatings etc. Every one of those is softer than brass and far softer than the steel of the firearm. For that reason even if there was a wear issue with cartridge cases rubbing somewhere on the firearm (there really isn't) the steel cases would cause less wear than brass.

Since the steel is not actually bearing on the extractor and in reality the soft steel of the cartridge case is substantially softer than the hardened extractor there is no more wear from steel than there is with brass. There is no more load on the extractor with steel because it comes free from the chamber quicker than brass and has less drag in the chamber. Because of that one thing I'd be more inclined to believe that brass is harder on extractors than steel. If the effort required to run with steel was really that much higher I'd expect to see soft crappy brass cases with bent rims a lot more often. So in reality, if the brass cases don't have bent rims from the extractor, why would the steel cases make the extractors break sooner? Why would steel wear the extractor more?

As a simple example from my own experience, a tale of the steel vs brass.
I had a post sample thompson 1928 SMG. We ran about 7000 rds of steel cased wolf ammo through the gun doing demos and machinegun shoots. I broke an extractor. It took us about 4 mags to finally figure out the extractor was broken because the gun ran fine with occasional cases being dropped back into the feedway. Maybe once or twice per 30rd mag. So I replaced the extractor. We ran a few thousand rounds of steel cased wolf through the gun with no issues. I got to a shoot somewhere and we ran out of ammo but a customer wanted to shoot the gun. He had a couple boxes of S&B brass cased 45 auto. We let him load up a couple mags and run the gun. After the first mag we had some odd issues with empties dropping back into the feedway and guess what? Broken extractor. So did the brass cased ammo break the extractor? All that steel ran fine but 100rds of brass killed it? In reality thompson extractors seem to last about 5000 rds or so and it doesn't matter whether its steel or brass cases. Not a measureable difference in anything we could detect. Rate of fire is the same, reliability is the same, wear is the same.

No real difference. So I say, shoot what you want, reload what you want, don't let guys scare you with tales of doom and gloom when most of them haven't even tried what you're asking about, they just have internet myth.

Just my 2 cents corrected for inflation

Frank

 

[BehindBlueI's]

http://www.luckygunner.com/labs/brass-vs-steel-cased-ammo/

Look at the magnified photos of the lip of the extractor yourself.

 

[amafrank]

I don't think the luckygunner test was very scientific. It was better than the TFB or whoever did the other test but they weren't comparing steel to brass they were comparing different ammo with different powders and had no controls to actually tell them which part was causing what damage. Powder can make a huge difference in bore wear, temperatures and operation due to varying gas pressures at the port. Over pressures blow the bolt open too quick and yank the cases out which will cause damage to the extractor with brass, steel or even aluminum cases. Lower pressures allow the bolt to operate properly where the gas pressure pushes the carrier and bolt apart which rotates the bolt and then the bolt is slowly opened as the angled rear surfaces let the bolt move rearward slowly to start with and then as the lugs clear the barrel extension the pressure in the barrel pushes the case out of the barrel as the bolt moves back too. No yanking.
A real test would have been loading steel and brass cases with identical powder, primer and bullets and then running it. All their test proved is that you can save enough buying wolf steel cased 223 to replace your barrel if you run it like they did.....at least when you compare the cost of wolf to the cost of the more expensive stuff they used.

Frank

 

[BehindBlueI's]

...they weren't comparing steel to brass they were comparing different ammo...

The OP already said he didn't reload, so that's exactly what he's getting. Different ammo. He's not going to pull bullets, use the same powder, etc. He's comparing factory ammo to factory ammo. Which is what LG did, albeit in a rifle and not a pistol. Which leads us back to steel wears guns faster. If "faster" is enough to matter is dependent on the gun, etc. etc.

 

[russc2542]

I don't think the luckygunner test was very scientific. It was better than the TFB or whoever did the other test but they weren't comparing steel to brass they were comparing different ammo with different powders and had no controls to actually tell them which part was causing what damage. Powder can make a huge difference in bore wear, temperatures and operation due to varying gas pressures at the port. Over pressures blow the bolt open too quick and yank the cases out which will cause damage to the extractor with brass, steel or even aluminum cases. Lower pressures allow the bolt to operate properly where the gas pressure pushes the carrier and bolt apart which rotates the bolt and then the bolt is slowly opened as the angled rear surfaces let the bolt move rearward slowly to start with and then as the lugs clear the barrel extension the pressure in the barrel pushes the case out of the barrel as the bolt moves back too. No yanking.
A real test would have been loading steel and brass cases with identical powder, primer and bullets and then running it. All their test proved is that you can save enough buying wolf steel cased 223 to replace your barrel if you run it like they did.....at least when you compare the cost of wolf to the cost of the more expensive stuff they used.

Frank

While unscientific in that it doesn't compare the wear from steel vs brass case separate from the contents of the case it's far more applicable in the real world where most people don't reload steel cases. The vast majority of people use steel cased ammo with the contents as delivered from the manufacturer.

 

[Expat]

While unscientific in that it doesn't compare the wear from steel vs brass case separate from the contents of the case it's far more applicable in the real world where most people don't reload steel cases. The vast majority of people use steel cased ammo with the contents as delivered from the manufacturer.

It is also consistent with other reports I have read from trainers that have seen many thousands of rounds put through their ARs over the course of each year.

 

[Vigilant]

Not to mention the laquer/polymer/chicken grease coatings most steel ammo "comes with" as an added bonus gums the crap out of chambers and actions. Steel ammo for commie guns, brass cases for everything else. Aluminum(Blaser) is just plain crappy ammo, and has no real business being near firearms. As is always the case YMMV!