Quote:
Originally Posted by
blaster
| thanks for the comeback & info. my blade is marked -.015 on the other side it is stamped N2 |
A "0" will give you 2.77" lower
A +015" will give you 4.5" lower
A +030" will give you 6.31" lower
A +045" will give you 11" lower
By aiming with the 'bull' sitting on top of the foresight you'll gain 'a bit' as well so you should be able to use a little bit of elevation on your rear sight with a 045 front blade.
The above is a pure approximation only - there is a formula if you want to do it correctly :
There is a linear relationship linking the distances between:
1. The front and rear sight distance, and
2. The change in height needed for the front sight of the rifle and the actual location of the bullet, above or below the bull’s-eye on the target.
Equation A = the distance from the rear sight to the front sight. Units are in inches and approximate.
B = the distance from the barrel of the rifle to the target. Example: 100 yards (3600 inches), 200 yards (7200 inches), etc. Units are in inches.
C = the CHANGE in height required in the front (or rear) sight. Units are in inches.
D = the height ABOVE or BELOW the bull’s-eye of the target. Units are in inches.
Note 1. On a SMLE the distance between rear and front sights is approximately 19.5 inches. 2. On a No4 MkI the distance between rear and front sights is approximately 28.5 inches. 3. On a No5 MkI the distance between rear and front sights is approximately 23.25 inches. 4. On a P-14 the distance between rear and front sights is approximately 37.75 inches. Actual Relationship A is to
B, as
C is to
D. Therefore, the formula is as follows:
A C
---- = ----
B D
Restated:
A x
D =
B x
C or
C = (
A x
D) /
B Example
A SMLE (fitted with a +.045 front sight blade) shoots a 5 shot group 8 inches above the bulls-eye at 100 yards.
C = (
A x
D) /
B.
C = (19.5” x 8”) / 3600”.
C = 0.043 inches.
Therefore, you must INCREASE the front sight height by 0.043 inches.
(+.045
add 0.043 equals +0.088, closest sight +.090)
(Just check out no screws, bolts or woodwork is loose first.)