Brezny rewrote the Article in the latest Wildfowl magazine. I have one of his Dead Ringer chokes as well as a custom made by Hajjar for my 935. They did not work for me. It appears they are shotcup sensitive. Also thproject found that full chokes give about 14 ft shotstrings while the Mod gave less than half of this. My 935 likes the Mod choke best for great tight patterns. Ned S the young 81 yr old