How does one locate and install a front sight ramp?

I'm rebarreling a custom sporterized Springfield '03 that my father-in-law had built for my wife when she was in high school (1956 - 1960). It was test fired with military ammo that had corrosive primers in it, not cleaned, and the barrel was destroyed. I tried to shoot it, bullets went sideways through the paper at 50 yards. She brought it with her, along with 6 other rifles and a revolver, when we were married almost 43 years ago.

I decided to rebarrel it for her as a 43rd anniversary present. I'm almost there.

I recently posted pictures of cutting the extractor groove in the barrel breech for an '03 Springfield action, that was for this project. Today I got the stock modified so that tne new barrel fits. This is what it looks like so far:



The barrel needs a front sight ramp, front sight, final polish and bluing.

I did some measuring on the old front sight as installed on the old barrel. From the centerline of the old barrel to the top of the front sight bead is 1.022". The ramp height measured from the top of the barrel to the bottom of the dovetail is 0.380". The barrel OD at the front sight is 0.594". The front sight itself from bottom of dovetail to top of sight is 0.345"

The new barrel OD at the front sight location is 0.667". To get the same height, bore centerline to top of bead, I'd need a ramp with a height of 0.345". Brownell's sells one, Williams, that mounts iwth a scre that's 0.3445" top of barrel to bottom of dovetail. That will work if this is in fact the right way to determine the required height.

My questions:

Is the above a reasonable way to figure out front sight ramp height, top of barrel to bottom of dovetail?

If not, how do I go about figuring out what height front sight ramp I need?

Once the ramp is here, what is the best way to decide where it should be on the barrel so the rear peep sight zeros about centered?

This, like some other features of this project (square threads and cutting an extractor groove), is a first for me. Any suggestions are welcome.

Thanks
Fitch

The Brownells catalog has a chart/explanation for establishing front sight height in it. For top center, I might just eyeball it or set the action up on a surface plate that is level and make it top dead center with squares or a level. There is a leveling tool made that is designed just for this application and I imagine Brownells sells it.

Gazz said:

The Brownells catalog has a chart/explanation for establishing front sight height in it. For top center, I might just eyeball it or set the action up on a surface plate that is level and make it top dead center with squares or a level. There is a leveling tool made that is designed just for this application and I imagine Brownells sells it.

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Thanks! That's exactly what I needed to know. I can take it from there. The chart answers my questions about height, and I have no problem setting it up in the mill to drill the holes centered on the barrel with the receiver dead level.

Fitch

Hi Fitch. That's a williams peep sight, correct?

When I fitted one of those to my daughter's 22, I did the front sight height by
guess-n-by-gosh by having the rifle sighted in using the blade sight, and the
the stock front sight.

Then I simply measured the altitude of the front sight from the barrel centerline
(using the diameter at the front sight) and the altitude of the more-or-less correct
rear sight notch, again at the barrel diameter near the sight to get altitude above
bore centerline.

With those calculated numbers in hand, I installed the new peep sight and more
or less put all the adjustments at mid-range.

Then measured the peep sight center above barrel center dimension.

That, subtracted from the original sight dimension above centerline, gave
me the number to *add* to the original front sight.

Brownell's had one that tall - *just*. It took a few hours of page-turning
to get the style I (she!) wanted in the height needed.

This exercise was one reason I went with a marbles peep sight when I did my
22 - I could be adjusted to be as low as the original blade sight, and I could
retain the original front sight.

Best to you and yours - Jim

(nice gun btw. Also I'd say the wife's a keeper if she arrives with her own
firearms. )

jim rozen said:

Hi Fitch. That's a williams peep sight, correct?

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Hi Jim,

Good to hear from you. It is.

(nice gun btw. Also I'd say the wife's a keeper if she arrives with her own firearms. )

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Oh yeah! Definitely.

Fitch

By "locate" it means you are trying to determine what front sight height you need correct? And not how to find the centerline of the barrel to mount the front sight if I understand you correctly.

The fastest and simplest way IMHO is to remove the bolt and use either a cleaning rod or other metal rod and pass it through the barrel so it sticks out the breech and muzzle. Use a dial caliper (or depth micrometer but that is overkill) to measure the height from the top of the rod to the center of the rear sight aperture with the sight at its lowest elevation. Now measure the height of the top of muzzle end of the barrel to the rod and subtract it from the first measurement and there you go. It will take you less time to do than it did for me to type this.

Fitch Williams said:

Hi Jim,

Good to hear from you. It is.



Oh yeah! Definitely.

Fitch

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Hey Jim what else do you expect him to say, his wife has a gun!

MarkW said:

Hey Jim what else do you expect him to say, his wife has a gun!

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<LOL> More than one!

I did much like what you recommeded, but I just used the barrel OD at the point where the sight would be located. You are right, takes longer to describe it than to do it.

Now I'm busy figuring out the right way to solder it in place.

Fitch

LOL. This is one reason I taught my daughter to shoot....

As for soldering, I'm not even close to a gunsmith so don't listen to me.
But I'd use 95/5 tin/silver soft solder if a low-temperature job was desired.
Stronger than regular lead/tin by about 3X.

Fitch Williams said:

<LOL> More than one!

I did much like what you recommeded, but I just used the barrel OD at the point where the sight would be located. You are right, takes longer to describe it than to do it.

Now I'm busy figuring out the right way to solder it in place.

Fitch

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Not to sound like a grumpus but I don't see where you have taken any measurements from the rear sight? If so you are replicating the height of the original front sight but that may not be the actual ideal height, which should be based on the height above bore of the rear aperture. I suppose instead of a rod you can pull back the bolt so the bolt face is below the sight and measure from the firing pin to the aperture but at least you are creating your own standard and not relying on someone elses which may not be as good as yours.

MarkW said:

Not to sound like a grumpus but I don't see where you have taken any measurements from the rear sight? If so you are replicating the height of the original front sight but that may not be the actual ideal height, which should be based on the height above bore of the rear aperture. I suppose instead of a rod you can pull back the bolt so the bolt face is below the sight and measure from the firing pin to the aperture but at least you are creating your own standard and not relying on someone elses which may not be as good as yours.

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I stuck the reamer I used to ream it into the chamber (it aligns perfectly) and measured from the top of the reamer shaft to the rear sight. Added half the reamer shaft diameter to that measurement. did the same thing with the indicator rod in the chamber. Got essentially the same result.

Turns out the rear sight and the old ramp on the new barel are within 0.005" of the same height as close as I can determine.

There is bunch of adjustment in the rear sight, it could go an eighth of an inch lower than it is, and up a half inch or more. I just need to zero it at 100 yards and I'm good, so this is going to work. But at least I know that now.

Fitch