...I read where someone made mention of the chambers on some rifles not liking the steel cased stuff. Although I have seen some chambers (non chrome lined or rough) that exacerbate the problem that some rifles have with steel cased ammo, it's usually not the chamber that is the culprit. ...This is usually caused by the rifle being over gassed, as is common for many carbines. Some are lucky because they can over come the problem with the addition of a better extractor spring and/or insert and/or the addition of a heavier buffer to slow things down a bit. From what I can gather, steel just doesn't contract as quickly as brass does, so it sticks in over gassed rifles. This is just a conclusion that I came to based on observations that I've made. I've found that on rifles having trouble with steel cased ammo, I've been able to alleviate the problem by using a clamp on gas block and just moving it just a bit forward or backward from the position where it's supposed to be, thereby choking off some of the gas. I've tried adjustable gas block a couple of times, but those are expensive. These days I just try to stick with good barrels with gas ports that are drilled to the proper size.
