The Howa 1500 S/A MMS-AICS Mag system is compatible with AICS magazines for short action receivers. The MMS-AICS system is designed for the professional with an ambidextrous push lever mag release. To release the magazine, simply push the lever without breaking your shooting position and the spent mag will hit the ground.
This is not a drop in unit and some gunsmithing is required.
Uses an Accuracy International style short action magazines