Author Topic: Sight Height  (Read 895 times)

Offline Jerry

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Sight Height
« on: March 11, 2024, 10:45:14 PM »
Can anyone tell me how to figure front and rear sight heights to cut out a lot of guess work? Many thanks, in advance. Jerry

Offline J Shingler

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Re: Sight Height
« Reply #1 on: March 11, 2024, 10:53:17 PM »
Jerry,
I start with about 1/4" and just shoot it and see how it goes. I have clamped it in a vice and looked down an unbreached barrel and then see if the sights are close, but usually at this stage its breached and not practical.  I guess you could measure across the flats divide by two to get center of bore to flat. Add height of sight then compare front and rear to get you in the ball park.
Thank you
Jeff

Offline smylee grouch

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Re: Sight Height
« Reply #2 on: March 11, 2024, 11:05:14 PM »
In the past I have tried to get the front sight CLOSE to .100 inch higher than rear when measured from center of bore as a starting point. Dont file any correction until you have found the best grouping load . So far this has worked well for me. YMMV

Offline recurve

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Re: Sight Height
« Reply #3 on: March 12, 2024, 12:39:15 AM »
to regulating a sight

       A=BxC/D
     
        A correction to sight

       B inches between sights (rear/front)

       C how many inches off aim point/bullseye

       D distance to target in inches  (900inches =25yrds)


this is how I found out how much to file off my rear sight to hit aim point above 
you should shoot a group then use the above to help get on target  first group 2 high then filed back sight
using the regulating formula
if the group was low I would have filed the front sight( high file rear/ low file front)
« Last Edit: March 12, 2024, 12:48:12 AM by recurve »

Offline Daryl

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Re: Sight Height
« Reply #4 on: March 12, 2024, 01:20:51 AM »
Over the years, we've found with open sights, that same height above the bore line (or center of the bore) for both rear and front sights, usually puts them on at 25 and 50yards with round balls.
Thus, level is usually the first "installation".
Then, find the accuracy load, raising powder charge from just above bore size until the groups shrink, then start to expand again.
Ball .005" to .010" smaller than bore size + 10 ounce denim that we measure at .021". If the barrel has rounded rifling, you are going to likely use the .010" undersized ball and
a LOT thicker patch to fill the grooves tightly.
Adjust one thing at a time. Pick up the patches and see if they are standing up to the 'gaff'. If they are reusable with the addition of more lube, they're fine with THAT load. They might
not be fine with more powder though, as more powder raises pressure and thus is harder on the patch's purchase and sealing the gas/flame and pressure behind the ball.
Our loads seal and thus we do not need a wad between powder and ball - the patch does it all. The patch must also be thick enough to carry enough lube to wet the fouling from the
previous shot to allow loading, pushing all of that fouling down onto the powder, to be blown out the bore next shot.
The lube also must lubricate that ball's passage out the bore and leave 'some' lube in the bore to soften that shot's fouling, allowing easy loading of the next patched ball.
« Last Edit: March 12, 2024, 08:22:55 PM by Daryl »
Daryl

"a gun without hammers is like a spaniel without ears" King George V