7 stw mag. box change

[skinny pedal]

I have a savage model 112 in 7 mm stw and i would like to change the box mag so i can maximize the the length of the bullets to be near the lands . from the factory they installed a box for a 300 mag whis is significantly shorter than the 7 stw. is this possible to do on the savage 112 and if so who can do it that is reputable .
thanks casey