Talk:P30L/@comment-38950410-20190613031728/@comment-39164063-20190706162026

FMJ stands for full metal jacket. Modern ammunition has a full metal jacket. Bullets are made of lead. I think lead is a soft metal. Someone was smart enough to cover lead bullets with I think copper. Maybe brass. IDK. Lead bullets dirtied the barrels. So with the FMJ, this problem was partially solved. FMJ is not the shell (I don't know.  I learned this a while ago.  I forget stuff easily.)