I have a tech question I could use some help with. My fiber optic front sight bead on my T/C Rengade is .0090" It is 28 inches from the
aperture sight. What diameter cirlce does it cover at 100 yards. That is, what is the MOA at 100 yards?
Thanks,

If my math is right it's 1.5" or 1.11MO MOA

my calculator says radius of 28" at 100 yards a width of .0093 = 1.2", so 7mm's figuring of 1.11 is probably pretty darn accurate.

If I could only hold to .11 at 100 yards I'd be a happy clam, LOL!

I blew it. That was .090" so I'll just multipy your findings times 10. So I cover 11.1 inches at 100 yards. I was shooting 5 1/2 inches low when I put the bead at 6 O C'Clock so if I hold dead on it should hit exactly center of the bead.

Copied and pasted from Brownells-

http://www.brownells.com/.aspx...orrection_Calculator



Formula:
Amount of Error X Sight Radius = Sight Correction Needed
Distance to Target

If you are shooting low, you would replace your front sight with a lower sight, and conversely, if you were shooting high, then you would replace your front sight with a higher sight. Add or subtract the number of thousandths needed to the actual height of your sight and you will have the correct height of the replacement sight.

Example
At 100 yards, your shot is 6" low and the distance between your front and rear sight is 19.5".
6 X 19.5 = .0325
3600

Since you are shooting low, you would need to lower your front sight by .032".



Anyway, can't you raise the rear sight any more, or if it is all the way up can you shim under the sight base?

Keep in mind the position of the rear aperture is irrelevant to the apparent size of the front sight, no difference between 4" or 28". The critical dimension is to the eye position. That is what determines the apparent size of the front sight compared to the target.