BARREL BENDING
FWIW I’ve successfully bent rifle barrels when desired not to move the sights way out of kilter … full octagonal & part oct/part round.
IMPACT FORMULA
The 'Formula' is relationship, where 'A is to B' is the same as 'C is to D'. This is expressed as A/B = C/D, where:
- A = The amount the sight (front or rear) needs to move (or be filed, where possible) in inches
- B = The distance between the sights in inches, or the sight radius
- C = How far away your impact is from your aim, in inches
- D = Distance in inches, at whatever yardage you shot
Example:
Let's say your 2" low @ 50-yards.
'A' is what you want to know. Let's assume you have a sight radius of 28", then
'B' = 28".
'C' = 2" and 50-yards in inches = 50 x 3- feet per yard x 12 inches per feet, so
'D' = 1800 inches.
Using the formula: You have A/28 = 2/1800. Then you
cross-multiply (top to bottom of each!) to get, 1800A = 56 (or 2 x 28).
Solve for 'A': Divide both sides by 1800 results in A = 56/1800, or 0.311" or about 1/32th of an inch that the
front sight needs to be filed DOWN to raise the point of impact.
NOTE - If you are printing
high, you can't UNfile the front sight to
lower the impact, but you could get a taller front sight or file
down the top of the
rear sight (if you have material to do so) and deepen the notch as needed. But be careful there, you need a thin file so as not to inadvertently widen the sight notch.