This glitch happens almost all the time when using the IZH-18 as a primary. I will load the round into the weapon and from there I am able to fire it. Yet if I return the weapon to my inventory and then re-equip it, I cannot shoot the gun (I get the clicking noise) and when I load the gun, I get a "The weapon is already full" message. In order to fix this, I must return the weapon to my inventory and re-equip it. This happens almost all the time with any gun I chamber. This does not happen to a weapon that requires either a clip or a magazine, or has an internal chamber.