GOOD MORNING 12borejimbo, the op is probably busy, so if this helps you out . the bifrost stock has extra picatinny rails and has a more rubberised texture but costs almost double of the fenris . if its a hunting rifle the fenris stock wont snag or catch as easily as the bifrost but the bifrost gives you a few more option if you range shoot .<probably best to look on the grs web site for a better discription than mine though >?