The Remington factory magazine has a stated capacity of 10 rounds. However only 9 rounds could be comfortably inserted into the magazines on test without excessive force. When the tenth round was inserted into the magazine, with the bolt forward, it would not allow the magazine to seat in the rifle without considerable force. With the bolt in the rearward open position, this was not an issue.
The magazines on test were fussy about the .22lr ammunition that they would feed. Federal High Velocity 525 bulk pack, American Eagle standard velocity and Winchester sub-sonic did not feed well with more that 4 rounds in the magazine. CCI mini-mag and CCI Standard velocity both fed flawlessly in full or partially full magazines.
Every factory 
10 round magazine has a last round bolt hold open actuator fitted to the follower. This is seen in the image to the left. This actuator on the follower pushes the bolt lock upwards to lock the bolt back after the last round is fired. The magazine base-plate protrudes below the stock enables the shooter to visually verify that a magazine is fitted. This base-plate protrusion also enables the magazine to be removed from the rifle easily.
This metal alloy magazine can be disassembled for cleaning and an improvement over the original plastic magazines for durability with the metal feed lips.
