I was hoping someone might be able to help me with a sight calculation. I need to raise the point of impact 30 inches at 100yds with the front sight. How much taller does the front sight need to be. The sight radius is 19 inches. Right now I have a .256 high NECG sight in it. I am thinking the .315 will get me close. Does someone have the formula for figuring it out? Thanks in advance.

Front sight needs to be shorter to raise POI.

Brownells has a handy dandy chart on their site.

Or, you can do it the old fashioned way:

The formula is: FSHC= SR x PIA / DTT
FSHC= Front sight height change
SR= Sight radius
PIA= Point of impact adjustment
DTT= Distance to target in inches.

You will need to raise the rear sight height.

Change = 30 inches X 19 inches/3600 = .158" shorter needed

You are planning on going the wrong way. You need shorter front, taller rear or a combination of both.

Sight height formula is correction needed times sight radius divided by distance to target all in inches.
So 30 times 19 = 570 divided by 3600 = .1583 and as you have a .256 sight at present if you shorten it to .0977 If that is not possible then you may be able to raise the rear sight by a portion of that differential and lower the front the rest of it.

Von Gruff.

I am sorry. It shoots 30" high. I need to bring the group down to point of aim. I have some room to file the rear sight, but I want to move as much as I can with the front before filing. It's express rear. Ideas on front sight height again?

Here's a plug in calculator.
http://www.brownells.com/.aspx...orrection_Calculator

By the calculations, I need a .414 front sight. NECG makes a .394 so that should be perfect and I can file the last .010. Please double check my calculations. Thank you all and I have saved the Brownells calculator to my Favorites for future use. Thanks again.

.414 - .394 = .020

YCMV

You need a 7/16 (.437) sight.

If you have no adjustment then file it down to .414.

0.20 is correct. Even better really. It gives me a little more room for filing it in.