New Sights - How To Set-Zero

[Gonfishn]

I'm refurbishing my No 3 in .223, finishing up the wood right now and I've recently installed new iron sights which were previously removed due to sight mounting by the previous owner. Had no problem wedging them in with a brass rod, etc., my question is whether there's a way to rough zero them, like make them parallel? I've been looking at gunsmith tools and noticed there's a sight setting tool, not that I'm going to buy it at 275.00, but is this what folks use to get a rough zero? Hope my question makes sense

 

[Greg Mercurio]

Bore sight them on an object some distance away. I do it with open sights and scopes. Very easy with No. 1 and No. 3's. Gets you on the paper quickly.

 

[pete44ru]

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If you find the bore sighting reveals that one of the sights is the wrong height, you can get in the ballpark with a few simple measurements & a little E-Z-peazy math.

The basic premise is that the total height, measured from the top, of the front sight (including the ramp, if the rifle has one) should be the same distance from the bore C/L as the sighting notch of the rear sight, with the rear sight's elevation adjustment in the middle of it's range.

After you work it out, I'll pass on the $275.....


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[JFB]

the math is easy

at the rear sight, take half the diameter of the barrel plus from the barrel to the top of the blade
at the front sight, take the same.
the two will be from the sight line to the barrel center.

you do NOT want the two exactly the same, you want the barrel angled up. the amount of angle depends on the ballistics and desired zero. for example about 5 MOA would give a 100Y zero with the below ammo.

to determine the angle requires a little more advance math plus the distance between the sights

angle = Inv tangent {(rear sight - front sight) / distance between sights}

IF the distance between sights is 16", setting the front sight 0.025" less than the rear would be a smidge over 5 MOA