I am thinking about porting M14 barrel (308) rather than threading and buying muzzle break. I have never done it though. How effective portnig may be or can it be as effective in recoil reduction as muzzle break of a good design? And how is it done? I am thinking - should I bore out last 2" or so and if yes than to what diameter? Assuming it is 308 barrel. Or should I live that portion rifled and just drill some holes. Holes - how big where and if there is any sence in drilling them at the angle in hope to deflect gases backward a little more? I also asked same question on main battle rifles forum. Thanx in advance