Roper's choke was actually a screw-ON device. It was a short ring that screwed on the outside of the muzzle.(single barrel only) I remember seeing it in a reproduction of an old Sears catalog. It is also shown on page 256 of W. W. Greener's "Gun and its Development". Greener also gives Roper credit for the first patent on a choke device, saying it precedes Pape's patent by about 6 weeks.

> Jim Legg <