It is a bolt action, there is no reason for it to lock open. Depending on the bottom metal, it will have either a fixed, top loading magazine with up to 5 rounds capacity or a removable magazine with, usually, 10 rounds capacity. Either way, unless you are in the heat of battle, counting rounds loaded and then rounds expended really should not cause a great deal of mental strain. I know how many rounds I intend to shoot and load that many. I often just single load each round, I have 4 bolt action rifles and have zero trouble push feeding rounds into them. 2 Remington style short actions, a Pierce and a Surgeon, a Ruger Gunsite scout and an ancient Mauser 98.