Hi, no mag mods needed to fit..forget the front, it does nothing and isn't in the way of anything. The T3 in Long action setup is limited on OAL allowed due to the action design, so it is limited to max OAL of factory 300 Wm rounds(about 3.400 Max OAl). for the 6.5×55, there is no OAL issue, and it jut is wasted real estate. IT will work out fine..