Bolt failing to go into battery....HELPPP!!!!!

[montana]

Remove your upper from the lower and remove the BCG. The chamber and throat needs to be cleaned thoroughly before this test. After the chamber and throat have been cleaned, put a factory cartridge in the chamber and lightly tap the back of the cartridge into the chamber with your finger. Tip the end of the barrel up and the cartridge should fall out. If it sticks, it could be a tight chamber. A function gauge works in the same manor..I would try different factory cartridges to remove any possible defective ammunition from the equation.If you have access to a case gauge, it would help eliminate the cartridges as the problem..