front sight

[blaster]

my Ishapore 7.62x51 with the rear sight all the way down, shoots about a foot high. does any one know where to get a taller front sight? or who makes a scope mount for them?

[Alan De Enfield]

1st question (and its not intended as ‘teaching your grandma to suck eggs) but are you aiming correctly ?
According to the original training manuals the MPI (mean point of impact) should be 3” above the POI (point of aim) at 100 yards – eg. you should be aiming at the 6 o’clock position 3” below center at 100 yards.

To enable Rifles to be zeroed, a moveable blade is fitted into a dovetail base,
thereby allowing the blade to be moved from side to side to correct lateral errors.
The Foresight Blades are. also made in varying, heights so that the vertical errors
can be corrected by the replacement of the existing blade by one of a different
height. There are varying sets of blades for the different types of Rifes, for Enfields there is one common rule.
A. blade marked O is provided, the tip of which when fitted to the Rifle is
exactly one inch ove the axis of the bore. All other blades graduate from this
0 (Or zero blade) either above or below it in.constant increments. In the case of
Enfields 'this increment is .015". If a blade is lower than the zero blade it
is refered to. as a "minus;' blade, and if it. is above it becomes a "plus” blade.

All blades are marked so as to be clearly recognised, those below the zero having
as a prefix the minus sign e.g. -.015". The "plus" sign. is not used, therefore a
blade with on1y a figure , e.g. .015” is always a plus blade.

The change of 1 blade height adds 2.77” at 100 yards (for a .303, it will be slightly different for a 7.62)

What blade number / size do you have in at the moment ?

Replacement blades are available from most Enfield dealers or ebay – but make sure you get blades for a No1 (SMLE) and not a No4

Some on ebay at present Item number: 180381216442

[Alan De Enfield]

Just a thought before messing about with the foresight :

The following is a list of faults which would tend to give inaccurate
shooting. These points should be checked before attempting to Zero

1. Badly fttting Stock Fore-end,
2. Loose Butt.
3. Loose Screws.
4. Loose or damaged Blade Foresight
5. Loose Block Band Foresight.
6. Badly fitting Bolt. It should bear evenly with Bolt closed and no 'slop'
7. Condition Of Barrel for wear, bends, bulges or cordwear.

8. Loose Backsight.
9. Trigger to Sear to Bolt interfaces

[blaster]

thanks for the comeback & info. my blade is marked -.015 on the other side it is stamped N2

[Alan De Enfield]

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.)

[blaster]

thanks again, now to find sight blades. If they are not expensive I'll buy a few different ones to experement with, I'm lousy at math.