A good cleaning wouldn't hurt. Sometimes a piece of crud in an extractor can produce undesirable effects. You mentioned that you just picked it up. Had it been cleaned at all before firing?
This may not be the problem, but it's a cheap and easy thing to eliminate.
"An armed society is a polite society." — Robert A. Heinlein
"After a shooting spree, they always want to take the guns away from the people who didn't do it. I sure as hell wouldn't want to live in a society where the only people allowed guns are the police and the military."
— William S. Burroughs