Originally Posted by t_humm
Whindam Weaponry SRC
DI gas system
Not brand new but I'm the first owner, probably 150-200 rounds through it (all brass until today)
The ammo was Tulammo .223
Steel cased FMJ
I took it home and knocked the case out with a cleaning kit and fired another 79 rounds of steel case through with no problems.
Here's the extractor, looks fine to me just dirty.
Just some thoughts:
Carbine gas systems tend to be a bit over-gassed. This is because of the gas port being closer to the chamber and also having more bore past the gas port before getting to the muzzle. So gas pressure at the port is higher due to the lower bore volume to drop the gas pressure before venting gas rearward into the bolt carrier. Gas is also vented rearward longer, because the bullet has farther to travel past the gas port before exiting the muzzle. This blows more garbage into the bolt carrier and action than you would get from a midlength or rifle length gas system. The higher pressure makes extraction a bit harsher than the other gas systems as well. Using a heavier buffer can make the extraction less harsh. Steel case rims are a bit more brittle and can shear more easily if a case is stuck and jerked more harshly.
The AR with its direct impingement gas system and steel cased ammo can make a dirty chamber faster than average, because the steel cases don't expand as fully and gas and carbon blow around the cases and dirty the chamber up faster. If the chamber was never cleaned of the factory oil with solvent and a chamber mop, that powder residue and factory storage oil could cool and make a gritty paste that would potentially make a prime place for a case to get stuck. Also if you cleaned it and stored it with excessive chamber oil and didn't swab it out before shooting it could I tease some hydraulic pressure around the case and make it harder to extract.
It doesn't seem to be an extractor problem, because it held on tight enough to rip off the rim.
None of what I shared may make you want to continue to use steel cased ammo. Just some things to consider for folks who do use steel case in ARs.