Had to switch rifles while running the @guardiantrainingcenter carbine 3 class.
Due to running my sandman s and alot of rounds. Took a water break and my chamber flag melted into my rifle. Do not use plastic chamber flags especially is you run a can and a lot rounds in short secession. I eventually got it all out at home , but had to switch to my bcm 14."5 w the p4xi on it to finish the class.
Check out Guardian Training Center. Excellent facilities and people.