How to make barret 50 cal more powerful? mw2, xbox 360?

Barrett is good because it has more magazines than the intervention. I would attach FMJ to it and use the perks Sleight of hand pro (for the faster aiming) Stopping power pro (for faster, more powerful kills) and steady aim pro (easier to no-scope at close range) or ninja pro (quieter footsteps, better for all the headsets on the 360). Use stun grenades, as they are faster and more effective than flash or smoke and use a semtex, throwing knife or claymore, your choice. This is a good cl for quicker kills with the barrett. Happy Killing!