Ok I'm trying to figure out what to use for bottom metal I want a detachable mag. I'm going to be building a 280 Sherman. So what are my options for mags? I seen the wyatts detachable mag on red hawk page but it doesn't give a oal for the mag. The other mag I found is only 3.41 and I need like 3.6. Or am I going to be stuck with a hinged floor plate? This will be a Remington 700 la on a Grayboe terrain stock. Any advice would be great.