Towpro thank you for the info, later Ray.
There is a lot of peep sights that also mount on the receiver. Some with target knobs, some without.
The advantage of the tang sight is a longer sight plain over the receiver mounted peep sight.
If you have a flip up rear sight the the tang sights can fold down so you can use them.
Plus they look cool!
If you get a flip up rear sight, be careful, there is one design that will wear the bluing away as you flip it up and down. I plan on just putting a blank in the rear dove tail.
I plan on putting a tang sight on my 1948 336SC 30-30 (in brand new condition!) and use it for some Lever action silhouette next year. This year I used my 1921 Marlin 93 in 32 special, but next year my Dad hopes to join me, and the 93 was his deer hunting gun.