I have a 16 inch Encore pistol barrel that I want to put an iron sight in front of the scope mount base. The Encore barrel where the sight/scope base mount is .995 in dia. The dia. were I want to mount the sight in front of the base is .800 dia. My question is what is the dia. of the Contender barrel base. I want to buy a Contender pistol rear sight if the dia. is close to the .800. Any info would be appreciated. Thanks Ron.