Here's yet another test I did once again today with a turkey gun of my friend wbowman. He bought a Remington 870 express , 20 gauge and bought a Pure Gold .570 choke for the gun. This gun has not had a thing done to it so today we got together and gave it a full blown test.
This is all done at 40 yards
To start - one shot with the gun and choke with No polishing
Pure Gold .570 choke -
Hevi 13 ,3in,#6 1 1/4 oz

now after I spent close to an hour polishing from a 000 steel wool with gun oil , then Grey scotchbrite, Red scotch brite,Blue scotch brite and then White scotch brite until it came out of the barrel clean white.
Pure Gold .570
Hevi 13 ,3in,#6 1 1/4 oz

and the last test after we finished,was with the Winchester SX copper/lead ,3in,#4 1 1/4 oz It is the target on the bottom of the 3, so I thought all 3 together would give a better idea how they all looked together.
Pure Gold .570