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

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[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

[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

[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.

[Maxwell Smart]

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.

[Peter Laidler]

Max has it. (thread 8). Just change one foresight blade and see what difference that makes. THEN work out what you need from that. Simple!

[browningautorifle]

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.

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