front sight height help

[ActionYobbo]

I have a No4 that I need to change the front sight. its out by 100 yards. 600 to hit 500 etc.
I use 6 oclock hold on a 9" target. I have finally worked up a load that works with the sight increments and it would be nice to actually have the ranges match. current front sight is a 015
thanks

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[Maxwell Smart]

So, at 500 yards range your shots are printing about 15" low when the sights are set as per "correct" graduations?

Does your 600 yard sight setting include the allowance for the 6 O'clock hold?

Is the 9" target size the diameter, or radius, or distance from aiming mark to centre of bull?

[CINDERS]

There were scads of threads on this very subject I was looking them up for E when I got locked into 2008 for some reason.
Best thing to do E is to do range time with this pet load and mark the setting down on a range card like we all have done and go from there honestly you will save yourself allot of grief because the trajectories of the Mk VII Ball and your load are vastly different and the POI will vary every range IE going from 400-500 may still not marry up with the settings.
I have 5 shooters they all have range cards all shoot the same load I know my T scope is basically +50yds on top of the range being shot (Thank goodness for sighters)

Like Peter has said you may be at 500 you know your sight settings with your load is say 525 +2 clicks.

Look up the threads on the matter the digest what is being said then make your decision, I never see getting range time to do up a DOPE card a problem on a nice fine day with some mates.

[browningautorifle]

you will save yourself allot of grief because the trajectories of the Mk VII Ball and your load are vastly different and the POI will vary

Everything was set for the factory load. No one seems to take that into account when their load is so far out. How does it do at 100 or 200?

Here, read these.

https://www.milsurps.com/showthread....hlight=zeroing

https://www.milsurps.com/showthread....=zeroing+rifle

[ActionYobbo]

Everything was set for the factory load. No one seems to take that into account when their load is so far out. How does it do at 100 or 200?

Here, read these.

https://www.milsurps.com/showthread....hlight=zeroing

https://www.milsurps.com/showthread....=zeroing+rifle

read all that but its nothing to do with what I asked.

If I shoot with Mk7 ammo and have to put the sights 100 yards higher than the target range how much lower foresight do I need to put on the rifle? there must be some reference chart to use for this. some one must have worked it out years ago.
With this rifle if I shoot with Mk 7 or my hand loads I hit almost the same spot on the target at 400 500 and 600 but the sights are not calibrated properly. The sights that are on the rifle are replacements that I put on. The front and rear sights were missing and a no drill scope mount was fitted to the rifle when I got it.
I have searched the topics and have not found what I need to know. The other choice is to buy a selection of front sights and try untill I find the correct height.
thanks for helping me with my frustrations

[browningautorifle]

thanks for helping me with my frustrations

Seems you have a problem then. We've come up with various things...maybe you should go back to the drawing board.

[CINDERS]

Hang on a mo and I will find something;
Try this I typed in the search bar; Calculating 303 foresight height and found this thread at the top have not read it all but it seems close......https://www.google.com/url?q=http://...vzDX11LW1rTOKw

I think the formula you require is written just above the 3rd chart down...

Here I even cut and pasted it so others can benefit from what was written;

To calculate the difference a change in foresight would make at the target in relation to the point of aim use the following formulae (in Inches).

(Range x Difference in Height of blades) divided by sight radius = variation on target

Alternatively to calculate the correct foresight blade to fit to a rifle to achieve zero use the following formulae (in Inches).

(Sight radius x the height of the group MPI -usually 5 shots- above or below the point of aim) divided by range length = the change in height of fore sight needed

[ActionYobbo]

Hang on a mo and I will find something;
Try this I typed in the search bar; Calculating 303 foresight height and found this thread at the top have not read it all but it seems close......https://www.google.com/url?q=http://...vzDX11LW1rTOKw

I think the formula you require is written just above the 3rd chart down...

Here I even cut and pasted it so others can benefit from what was written;

To calculate the difference a change in foresight would make at the target in relation to the point of aim use the following formulae (in Inches).

(Range x Difference in Height of blades) divided by sight radius = variation on target

Alternatively to calculate the correct foresight blade to fit to a rifle to achieve zero use the following formulae (in Inches).

(Sight radius x the height of the group MPI -usually 5 shots- above or below the point of aim) divided by range length = the change in height of fore sight needed

those formulas are fantastic. using those formulas I need a -2.5" front sight. work it out to see if I made a mistake I am 15" low at 300

Exactly...or don't you shoot at closer ranges?

the range I shoot at is 300 to 1000. there is a 50 yard range 90 minutes drive form me but its a $100 a year membership
the ranges I shoot at are 25m rimfire of 300 to 1000 fullbore

I'll stick my neck out....

Having measured that 1 click of the No 4 rear sight moves the leaf near enough to .008", by my reckoning you could try a -.045 foresight.

Logic for this is that there are 7 clicks between 600 and 500 on the rear sight, so the sight change required is .056". Each foresight blade increment is .015", so if you came down by .060" I think you would be fairly close.

I too would be interested in how your rifle shoots at the closer ranges, and how the 6 o'clock hold issue enters the picture.

In my own case, I choose to zero (centre hold) at 100 yards; then use a 7 click elevation offset after changing sights for range to allow for the 7 inch distance between aiming mark and centre of bull.

thank you. this is what I was looking for.
I will buy a -.045 front sight and try it

[Maxwell Smart]

Mr E, where does your 6 o'clock hold come into the picture?

When you say that your sights are 100 yards out, is this for a centre hold or 6 o'clock hold?

[22SqnRAE]

Mr E,

I am having similar problems and have had to learn quickly. You have probably already thought of the following suggestions, so bear with me as I'm not insulting your intelligence, research or preparation.

Cinders is bang on with the formulae and every Lee Enfield owner needs a copy of these to understand their rifle. Brian's #11 post is the next excellent part of the equation.

The REME Armourer's Training Pam indicates the tabulated data for zeroing each of the Service Rifles at 25 yards and 100 yards. You've got a problem in being only able to use 300+ yards. OK, here's the suggestion. Like previously mentioned, grab a suitable (big) target like a pistol target and bung it up at 300. Set an aiming mark, shoot three to five 3-shot groups, comfortably, from a fully supported position. Grab the target and measure up the MPI for the groups.

Use measurements by dividing the difference between the MPI (observed) and the MPI (theoretical) and divide by 3 to bring it back to 100 yards and therefore MOA.

From what I have estimated from commercial ammo 174 and 180 gr projectiles, for a 200 yard zero, the MPI at 300 yards will be around -10.5" to -11.5"

With Agent 86's excellent info on the rear sight movements for the No 4, you have enough variables for the equations to determine the required foresight. The exercise is simple linear geometry. Keep all units the same and you can't go wrong.

In summary: sight at 300, reduce to 100 yards numbers (simple triangular ratios) and you then have the measurements to assess changes in accordance with REME Armourer's instructions. There are reproduced in part in the link:

http://www.rifleman.org.uk/PH_Service_sights.htm Scroll down to Zeroing...