Oh! I saw the "screw in straight rifled choke tube" but I wasn't familiar with the meaning... I read it as "screw in straight, rifled choke tube" rather than "screw-in, straight-rifled choke tube".
Couldn't figured why you'd want one that screwed in crooked anyway!
Still happily answering to the call-sign Peetza.
The problem, as you so eloquently put it, is choice.
He is no fool who gives what he can not keep to gain what he can not lose.
-Jim Eliott, paraphrasing Philip Henry.