Here's the bottomside of a windage adjustable sight that was on a 1916 Mklll* RSAF Enfield , which was pinned through the adjustment screw . The knob was long gone . The sight's serial number matched the receiver/bolt/barrel.
A fully functional w.a. rearsight
I also have an , all matching , 1918 BSA Mklll* Brit civi converted and stamped .410 - 2 1/2" , re- BNP'd to 3 1/4ton . Singleshot , standard Mklll* rearsight.
Interesting that it has the Fulton Regulation stamp ontop the barrel knox and the stocks are still cork bedded with barrel supports , so at one time it was used for targetshooting.
The mag , (which is actually for a Savage No4) has the ears ground off and the follower is spotwelded into place as a stationary loading ramp.
I've had alot of fun with this .410 , including some bunnie hunting.
I got 5" groups using slugs at 75yd , but I think that could be tightened up some with abit more shooting time.