Hammergun thanks.
The chamber was measured with a telescoping gage, I put it in at an angle and then tightened and moved it to the rim of the chamber next to the extractor and it measured .691-692 a few times. I used a Shurshot Remington hull and like I stated that miked .698. My friend tried new RST 20 ga. hulls and Winchesters.
The chamber is clean, the hull went in smoothly till it came to the brass and stopped.

David