Home Forums Hunting & Shooting Handguns POI change with front sight height?

Can someone tell me the formula to calculate moa change with a change of front blade on a pistol.

Specifically, I painted the front sight on this new Ruger 4.4 inch 22/45. The top of the blade is bright green. (.2 inches). Then if you raise the muzzle, the red bottom of the sight becomes visible.

Brownells has formulas or use to

This is what I can find.

Tan X equals b/a. b is blade height, a is sight radius.

.12 in blade height change in 4.5 inch sight radius yields tan .0266.

Arctan .0266 equals 90 moa.

That seems like a lot just off the top of my head.

Dawson Precision has a formula on their website, it's useful for such things (they sell all kinds of replacement sights) for all manner of pistols.

It is simple. .2 divided by sight radius times distance to target equals how much elevation difference it will make.
OR divide the distance to the target in inches by the sight radius times .2
Try it compared to all the other answers you get.

How long did it take you to Google that Jason?

That's interesting. Where does front sight height enter the equaition? How do you turn it into an angle measurement?

Actual front sight height isn't a factor, the important part is the distance between your two reference points on the sight. As I understand the problem, you want to know how much higher the bullet will strike using the top portion of the green part vs the red part .2" lower.

Just solve that formula using a target distance of 100 yards or rather 3600 inches to get direct MOA, since MOA = 1" at 100 yards. (Yeah, it's 1.04" but let's not get carried away.)

I don't know the actual sight radius of your pistol but a 5.5" barreled Mark IV has a 7.5" sight radius, so assume a 4.4" barrel has a 6.4" radius.

Using this example, your formula is (.2 / 6.4") x 3600" = 112.5" or roughly 112 MOA. So, the bullet will strike 112 MOA higher using the top of the green portion vs. the red portion.


Now just plug in the actual sight radius of your pistol to get that accurate to the last inch. (.2 / actual sight radius) x 3600 = actual MOA

Put a piece of tape on site using the edge as the line. Adjust the tape as necessary to get your hits. Paint it when done. While it sounds great, in practice it's hard to not have the front site will cover your target when you use the painted line.

I don't have the exact measurement of sight radius or blade height change at this point. I am sure that 6.4 inch measurement should be close.

I am at work now and trying to get a feel for the situation when I get home and take careful measurements.

That is my thought, to bring the gun back on target at 50 or 60 yds, vs the 15 yd sight in.

I may have to use a smaller differential.

I approached it the same way and also came up with 112 moa.

I used 3600” (inches in 100 yds) divided by the sight radius in inches (6.4) and then multiplied by 0.2 (the change of sight height or amount of change per 6.4” of travel)….(3600”/6.4”) X 0.2.

I know a .02 will change impact about 3 inches at 25 yards on my Glock, a .2 change is 10 times greater, so that would pan out with the math above, give or take.

Sitting at the desk with the calipers.
Sight radius is 6.62 inch.
The band of green at the top of the sight is .09 inches.
0.09 in/6.62 in yields tangent .0136.
Arctan .0136 yields .78 degree or 46 moa.

Which puts me on target well in excess of 150 yds.

Absolutely useless in this scenareio.

A band of color which would do what I was thinking, would be invisible. So I will just paint the rest of the sight red.

No harm, no foul.

The calibrated front sights will have to be relegated to the boomers shooting out to 500 or 700 yds.

Error x distance between sights / distance to target

Use inches.

Example: my SW622 has 8" between front and rear sight, and my sights are off by 2" @20yds.
8" x 2"/720 = 0.0222" of sight adjustment.

If they were off by 2" @100 yards
8" x 2"/3600 = 0.0044" of sight adjustment.

1 moa at 100yds is 1.047".

2 inches divided by 720 time 8 gets the same thing.
2 divided by 3600 times 8 gets the same thing.
Simple.

Sis probably thinks "Kentucky elevation" (related to famous "Kentucky windage") would be simplest to use.😆😂🤣.