ATI M1500 Detachable Magazine Short Action Conversion Trigger Guard Howa M1500 and Weatherby Vanguard Short Action Magazine System. Turn your internal box magazine and hinged bottom metal into a detachable box magazine! This detachable magazine system from Adaptive Technologies is made of tough polymer and has been designed to be installed without modification on most injection molded stocks. Wood stocks may require modification. Made for target shooters and varmint hunters, this trigger guard and magazine release bottom metal replaces your factory hinged floorplate and trigger guard "bottom metal" and takes the polymer ATI Howa 10 or 5 round detachable magazines.