Front Sight Height

[cwheel]

Good morning,
Have the loads dialed in on my old Winchester 94 in 38-55. Cuts 2-3" groups @100 with a 265 gas checked boolit and 29gr. of 3031 at 1600fps. It will hold this group very consistently if I give time for the barrel to cool in-between shots. The problem is that this rifle cuts that group almost 16" above the point of aim. ( front sight is to short ) This old rifle has the rear ladder type sight, ( not the buckhorn with the elevation stepped wedge adjustment ) and with the slider down their is no adjustment. This rifle also has a blade type front sight that looks like the elevation adjustment is to file the front blade, front blade is just a pinned insert. Question is their a chart somewhere on line showing changes in point of impact with changes to the front sight blade height ?? This rifle has a 20" barrel, but a chart for longer could get me in the ballpark and I could adjust for zero with a slightly taller sight if needed. Thanks for the help,
Chris

[pietro]

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Here's Brownell's sight height calculator: http://www.brownells.com/.aspx/lid=13186/guntechdetail/Sight_Height_Calculator


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[JSnover]

Here's a good read: http://www.texas-mac.com/Sight_Radius_and_Sight_Settings.html
The math is pretty simple.

[cwheel]

Thank you both, this was exactly what I was looking for. The Brownell's calculator showed I was a full .156 low on my front sight blade, I'll make a new blade and give it a try. Thanks again,
Chris

[Tom Myers]

Thank you both, this was exactly what I was looking for. The Brownell's calculator showed I was a full .156 low on my front sight blade, I'll make a new blade and give it a try. Thanks again,
Chris

Chris,

Experience has taught me to always make the front sight slightly taller than the calculated height and fire a test group, then file the height down as needed. (One or two very light file strokes and then recheck point of impact)

Front sight metal is easily removed but sure is difficult to replace.

[country gent]

This works good too. error in inches X sight radious in inches /distance in inches = amount to move sights in inches. Error= what its off on target in inches, Sight radious= distance between sights in inches, and distance = range it was shot at in inches.

[cwheel]

It's a carbine, 20" round barrel, and a older one, 1917 production special order. I've loaded this one down and up, best groups seam to happen in the 1600 fps range. Sure, these were loaded with 255gr. from the factory, and I'm now loading 265 gas checks, yes there is a difference there. Loaded up at 1600 fps this rifle shows no signs of pressure, easy extraction, almost no primer flattening. In my loading manuals it states that many 38-55's show signs of excessive headspace, this one has good headspace and is generally in good condition. 1300 fps will kill a deer just as dead as 1600, just closer in, and out west, our shots are sometimes longer. This is being loaded and setup as a hunting rifle, and not for range use, the extra 300 fps could take the effective hunting range to 150 yards or so without having so much drop. All valid considerations though. My research has shown that the Factory Winchester 255 loadings during the day were around 1300 fps. The Canadian Imperial brand loaded the same bullet to 1600 fps. I got 2 boxes of the Imperial factory with the rifle, ran 3 through the chrony. Looking at the front sight with 30X magnifier, I can see clearly the marks left by a file, why, I don't know. I did take down some of the pre-WW2 reloads my grandfather loaded, couldn't ID the powder, could also be that powder is no longer made ?? Same mold he used, his mold, Ideal 375296, same boolit loaded into his pre-WW2 reloads. Was he running slower, think so. Not a option to change loadings with this lot, it's loaded and filled 2 30 cal GI cans. Last part is doing the sight height adjustment, dialing it in, before passing this to my grandson for his first hunt.
Chris

[fouronesix]

Kind of odd that many if not most of the original Win carbines used that sight set up. It's as if something like 200+ yards was going to be the closest range they would be shot at :)

The most direct way to get a correct front sight height is to set the rear at lowest point and estimate/adjust at the range. You can eyeball an approximate height at the range with the gun in a cradle while looking at the height needed. 16" elevation is easy to see and can be measured with a caliper while looking down the barrel. Use a sharp, black bull @ 100 for consistent sight picture.

Basic hand tools like drill, punch, hammer, hacksaw and file are easy to use.

Simply fashion a tall enough (slightly taller than estimated) steel blade based on the above described visual estimation, replace the short blade, shoot and file the taller blade at the range to desired POI. Sand and "blue" or black to desired color and texture.

[Nobade]

Sights were likely originally for black powder loads. Those rifles could be ordered both ways toward the end of the 38-55 production, and you can see why. If it has a pinned-in front blade just replace it with a taller one and file to zero as has been mentioned.

(distance to target in inches/error in inches) * (sight radius in inches/X)

solve for X, that's the difference your new sight needs to be from your old one.

-Nobade

[cwheel]

Nobade, think you are probably right about the black powder sight height. Yes it is a pinned-in blade. The Brownell's calculator places me .156 low. Think if I make it + .187 there should be enough to file back to what I need. Blade is made from common steel .0625 thick, have the stock already.
Chris

[Nobade]

Good deal! I'm glad it's an easy fix. Rifles are sure a lot more fun when you can hit what you're shooting at with them. Get it zeroed, then see what the steps in the rear sight give you and play with it plenty so you know what it'll do at various ranges since you have a good load worked up already.

-Nobade

[pietro]

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After verifying the sight height by zeroing, You might want to think about measuring the final result & ordering a Gold or Ivory bead sight blade in that height.


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[cwheel]

If Brownell's sells that height and style, I'll sure look into it. I'm having a tough enough time seeing the front sight with these old eyes as it is now. Think gold or ivory would help the grandson as well after dialing in the height of the blade. The rear tangent sight, when flipped up, is graduated from 0-20. If the 20 = 2000 yards, someone was dreaming about shooting at something that far with this rifle. Sure would help to be able to see the front sight a little better though. Gold or Ivory sure would make a difference.
Chris

[pietro]

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Alternatively, a new/bright front sight blade for the correct height could be fashioned from an older Silver US Dime coin.

http://www.gun-parts.com/peepsights/nov30_02.jpg

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[cwheel]

Pietro, the rear sight pictured is exactly what I have, but the base of the front sight is machined into the barrel and a part of it, no dovetail. Blade itself is replaceable, and that's what I'll end up doing, just the blade. Thanks for the thought though,
Chris

[dlbarr]

Simply fashion a tall enough (slightly taller than estimated) steel blade based on the above described visual estimation, replace the short blade, shoot and file the taller blade at the range to desired POI. Sand and "blue" or black to desired color and texture.

The front sight on my NEF Handi Rifle proved to be too short once I installed a Williams rear aperture sight. My solution was to solder a 16 penny nail on the top of the front sight, trim it down to match the width/length dimensions of the sight, take it out to the range for a sight-in. With a few adjustments and the top of the "nail sight" filed flat, was back in business.