This one I have to disagree on . With 308's vs AR15's ... Mag Catch , Mag Release , P &T Pins come in a kit now , just buy one. A decade ago we had to buy these separate or get a 308 LPK for $30 more than an AR15 LPK. I always used a DPMS mag Catch or an Armalite mag catch. The couple millimeters of height always helped.