300W Gas port size with 20" barrel

[txjm]

All the discussions I have found on port sizes refer to sbr, pistol and carbine port locations. Most of those are subsonic applications. I am having a problem trying to get a 20" barrel running with supersonics. My port size is .096". The port location is in a normal rifle position. My barrel is a Remington take off that I rechambered to something similiar to what others refer to as a 7.62x40. The closest to ejecting brass I have come is for the brass to jam in the port as the bolt closes. I am running about 2250 fps with A1680 and a 125G BT. I am scared that I should have put the port in the carbine location. I have only taken it to the range once. When I removed the gas block the port seemed to be a little clogged?? What is the best way to ensure the port lines up with the hole in the gas block? I am using a EGW clamp on gas block.
This seems to be a great forum. I am very enthusiastic about the whispers. I have a contender 10" 300w, a 1.5" 284W wildcat that I shoot 200G lead out of and this ar. They are all a blast.
Thanks

I notice I am probably on the wrong forum. Move if you want to. I will do better next time.