Are you handy with tools? If it has the typical small "v" on the rear sight use a small flat jeweler's file on edge to re-shape it to a square bottomed "U" shape. I found that doing this on a few rifle sights now has greatly improved my ability to see the front post. Seems that the the sides of the new "U" notch act sort of like a small aperture peep sight and this let's my old fuzzy eyes see the front post a lot more sharply.
I got the idea from my Mosin Nagants. The post war M44 came with this sort of deeper and wider easy to see "U" where the wartime 91/30's had the little whisper of a "v" that I could barely feel with a fingernail, let alone SEE the darn thing.
Speaking of which.... With the new "U" notch I no longer try to put the bead of the front sight directly on the target. It's too hard to estimate the proper height with the fuzzy old guy eyes. Instead I treat the bead as part of a plain front post and just line up the top of the bead with the sides of the U notch like a pistol or military style rifle. I adjust the elevation so the round passes through the target at the top of the middle of the front blade or post with that setup. Again this enhances the ability to make do with the plain iron sights.
To see if this will help you in your case get some soft steel pipe strapping and cut the end to form such a flat top with "U" notch. remove the rear sight of your rifle and duct or hockey tape (what two products are SO Canadian as these?
) your makeshift rear sight to the barrel at the right spot and see if it works for you like it does for me. If it doesn't work then at least you know and can move on to some other option.
One you can try using the same pipe strapping is to bend it so that first one of the larger holes is presented to use as a ghost ring rear sight. And if that doesn't work rebend and tape it back on with one of the smaller nail holes as a long relief rear peep. If you're like me the bigger screw hole will serve well as a fast view ghost ring style rear sight when the surrounding metal is narrowed down to about 2 to 3 mm or 3/32 to 1/8". The small hole won't do well at that distance from the eye more than likely.
But now try moving the small hole to the rear of the receiver just in front of the hammer. If it works now then a good option would be a Skinner rear receiver mount sight.
Best of all you can try all these options for no more cost than an hour or so of tinkering time, a $7 mini file set and about a nickel's worth of plumber's pipe strapping. And both the files and strapping will certainly be useful for later on. And since it's all just a "Tape N' Try" thing at this point you're not doing anything that you can't simply take off and restore the gun to stock.
