have you followed the break in procedure in the owners manual ? probally 500 round breakin ,clean and oil every 100 - 150 rounds. if you ran 300 through the gun it should have been cleaned and oiled at least twice. 300 on a new kimber ,no cleaning,1 stovepipe i think you have a good one.kimbers need well taken care of. if this helps post a reply as this advice has been given before but i have never read if it has helped , i'm sure other members would like to know also. good luck!!