it's a adjustable choke for the tip of your barrel
Au contrair...it is not a "choke", it is a barrel weight adjustment system that supposedly lets a shooter "adjust" the vibrations in the barrel when it is fired to get better accuracy.
Sometimes you get what you pay for, sometimes you only pay more for what you get.
Three shots are not a "group"...they are a "few".
If the Bible is the literal, infallible, unerring word of God...where are all those witches I am supposed to kill? (Exodus 22:18)