i know that this is an old Thread,but felt a need to share my experiences. I looked at tge S&W 500 and n460 mag hand guns. Shot both with and without. With porting is better in fact much better. I have a Browning Highwall B78 in 7mm mag, 26 inch barrel. I had it sent to Magnaport to have it done after shooting a 308 my friend had sent to them as well. It helped his rifle. He and i shot my B78 7mm magbefore and after with the same 150 grain handloads. Definitely better on the browning as we both noticed a better shooting gun much easier on the shoulder. A muzzle break would be better but that would butcher such a beautiful rifle. The erade off is Magnaporting is less effective but nowhere near as loud as a muzzle break. Porting and brakes work better and more effective on magnums and longer barrels. Well worth the 150 plus return shipping. Less muzzle flip and noticably less felt recoil as well.