Front Aperture Sight Inserts for the Hy-Score Mod SM 810 (Diana Model 65)

I finally got around to making some front aperture inserts for my Hy-Score Mod SM 810 (Diana Model 65) rifle. I wrote an article showing how to do this before, but I figured I could show a few details. The insert size is smaller than on my Diana 75, I measured .618" (15.7mm) diameter of the one insert the rifle came with. The insert that came with the rifle has a 3.8mm hole, which is a bit too large for 10M shooting.

I chucked a rod in the 3 jaw chuck to take up the play and bored a small step to hold the insert.

Drilling some holes.

A stack of inserts turned down to size.

Ready for final drilling.

Making the 60 degree cone, I decided to try a steeper angle than I did previously (90 deg.), as I had a chance to look at one on a friend's rifle and it looked closer to 60.

Drilling the hole. I used a combination of metric and number drills to make a range of sizes.

After drilling I used pin gages to determine the actual aperture size. Each insert gets put in a small baggie labelled with the diameter.