Uberti vs. Colt Sig Series

[Tommygunn]

That anti gumming collar as you call it is a gas ring and was also on the originals and carried over to the 1873 SAA. With the open tops with the gas ring it is imperative to have the arbor length exact to keep from binding up the cylinder.

OK. Correction noted.
I was aware the 1873 had a similar ring. I have 2 Ubertis that have it -- although the ring is apparently part of a bushing that removes.
I don't believe my 1871 Opentop has a removable ring .... although I haven't checked it so I could be wrong.

Geeeesh ..... it's hard to keep up with you guys!