I picked this sight up recently, the box says "66r" for rem 760/740 but I don't think so. it is marked "lyman L E" anybody have an old chart?
Just a guess - could it be for a Lee Enfield? Perhaps a Lyman model 57LE. Bob
I was thinking the same, just don't know for sure.
Looks to me like the box may be correct: flat mounting base and rounded top of receiver.
Added: yes, it does look like it mounts on the right side. I did not catch that. It is not for a Rem 760 / 740.
"the box may be correct"..............the 740/760's mount on the left side, this one mounts on the right side ??
I agree with @BobJudy . The Rem 740/760 doesn't have the "step" between the flat side & the rounded top. Look at a Lyman 48LE sight which is similar.