Ruger's Big Bores: The 99/44 Deerfield & .45-70 No. 1

Guns Magazine, May, 2001 by John Taffin

Simply sight in with the scope, remove the scope, and install this receiver sight. Once sighted in, the receiver sight can be removed and placed in pocket or pack, and the scope can be reinstalled. If you encounter bad weather or very heavy cover that makes the use of the scope difficult, all you need is a large coin to remove the scope and replace it with the peep sight.

Another excellent idea.