I just installed a tac 21 chassis on my remington 700 308. I have an AI 308 10 rnd mag that doesn't fit, it's like the mag is too long and the tab is not catching the mag release. I tried my 10 rnd 223 mag and it works fine. When I contacted mdt, they asked where I got the mag from and said AI makes different length mags. I bought the mag from mystic precision and it should be the aics mag. Has anyone else had this problem? How do I fix it?