these depend on the opposite rail to hold them on- works EXCELLENT on my ar b/c it's the one with the integrated carry handle- completely useless on the m14s with the scope mount- tried all kinds of fasteners- finally got it to work with INDUSTRAIL GRADE velcro- the one for the 45 you HOLD it on with your right hand- again useless for me as i'm left handed- and i should add, EXPENSIVE AS HELL to get across the border