I want to replace the aperture on my Bushmaster.  I'm looking for a smaller aperture.  I've googled this and found some replacements but nobody seems to have good descriptions about what replacements will fit what firearms - maybe because they're all interchangeable?

 

Any advice appreciated.

Can tell you how to make one if you want.  Did one for my M1 years ago.

If you want a smaller aperature, you probably want a match grade or national match grade. Also, if you go to a smaller aperature it is advisable to go to a thinner front sight post as well.

Can tell you how to make one if you want.  Did one for my M1 years ago.

 

I'd like to know.

I took an allen head cap screw, drilled a #60 hole in it, tapped the original aperture, trimmed the screw to length, inserted it in the threaded hole.

you have a hooded aperture rear sight.  You can adjust the hole to the diameter you like.

I'd like to know.

I took an allen head cap screw, drilled a #60 hole in it, tapped the original aperture, trimmed the screw to length, inserted it in the threaded hole.

you have a hooded aperture rear sight.  You can adjust the hole to the diameter you like.

 

That's a good idea.