Hey everybody! I was out shooting my cousins AR15 a few days ago and it kept getting a round stuck between the action and the mag. I am unsure of the AR's build however I know that it was built to be legal in california. Meaning 10 round semi auto, however it is a 20 round clip with blocks in it to stop it at 10 rounds. Could these blocks be putting uneven pressure onto the spring plate in the mag and do this?