Here's how it works.
The flash hiders and front sights on these 18.5 factory rifles are the standard offering from norinco/polytech. I could be wrong but I don't think they purpose made them for the shorter barrel.
On the shorter barrel, the front sight dovetail needs to be higher, the blade sight remains the same. In theory, this would allow the standard G.I. Spec front sight to zero at 100 with the elevation set 8 clicks from bottom.
With the massive variances in chinese front blade height, it is hard to just throw a measurement and say, your blade needs to be "this high" .
So, take your rifle, follow this procedure.
-set up a big full size target at 100 .
- set elevation 8 clicks from bottom and fire three rounds at center, off the bench or rest.
-observe point of impact in relation to point of aim and record on paper.
- if your shooting low, removing approx 7 to 8 thou from the blade will RAISE elevation at point of impact approx 1 inch. So for each inch low, calculate 7 thou per inch required to achieve 8 click 100 yard zero
The opposite is true.
If you are shooting HIGH, adding 7 to 8 thou per inch high will bring the point of impact 100 yard zero to agree with 8 clicks from bottom.
That's about as easy as I can explain it.
The flash hiders and front sights on these 18.5 factory rifles are the standard offering from norinco/polytech. I could be wrong but I don't think they purpose made them for the shorter barrel.
On the shorter barrel, the front sight dovetail needs to be higher, the blade sight remains the same. In theory, this would allow the standard G.I. Spec front sight to zero at 100 with the elevation set 8 clicks from bottom.
With the massive variances in chinese front blade height, it is hard to just throw a measurement and say, your blade needs to be "this high" .
So, take your rifle, follow this procedure.
-set up a big full size target at 100 .
- set elevation 8 clicks from bottom and fire three rounds at center, off the bench or rest.
-observe point of impact in relation to point of aim and record on paper.
- if your shooting low, removing approx 7 to 8 thou from the blade will RAISE elevation at point of impact approx 1 inch. So for each inch low, calculate 7 thou per inch required to achieve 8 click 100 yard zero
The opposite is true.
If you are shooting HIGH, adding 7 to 8 thou per inch high will bring the point of impact 100 yard zero to agree with 8 clicks from bottom.
That's about as easy as I can explain it.
