thumper,

Good question.

It's very hard to explain but I can't post photos but here goes.

The Rigby Bissell rising third bite was a Patented action that was used by
Rigby (I think exclusively) that had a metal loop as a Dolls head
extending from the barrels.

In the action itself, it had 1 solid piece of metal and one piece that went up
and down when the Toplever was pushed over.

It was neat but I would say expensive to produce as Rigy went to
Webley actions after about 1920 so it was only made for a short time
- probably Max 20 years.

It's described in various books.

If someone can PM me an email address I'll email a Picture to post.

Hope this helps.

500 Nitro