Adjusting elevation with a ladder sight?

[2ndAmendmentNut]

I have an 80s era Browning 1886 SRC in 45-70. Beautiful rifle, with a slick action. It feeds and shoots MiHecs 462-420 Hollow Base (392gr) boolit wonderfully. My issue is this particular gun used to shoot about 18" low at 100yards with the ladder style sight in the folded down position.

I would like to zero this rifle at 100 yards with the sight down, but I have already filed the tall front sight down as short as I can and the rifle still groups about 4" low. Is there any way to lift the rear sight in order to get the rifle zeroed in?

[Tatume]

The only way I know to resolve your dilemma is going to be complicated and moderately expensive if you can't do it yourself. Remove the rear sight, and carefully file the rear face of the rear sight flat. Solder a flat piece of steel (or other metal if you prefer) in place, and file it to conform to the original shape except about 1/8" taller. File a notch in the new rear sight blade. Polish the blade and add cold blue.

It will now probably shoot too high, and you will need to install a new front sight.

[2ndAmendmentNut]

The only way I know to resolve your dilemma is going to be complicated and moderately expensive if you can't do it yourself. Remove the rear sight, and carefully file the rear face of the rear sight flat. Solder a flat piece of steel (or other metal if you prefer) in place, and file it to conform to the original shape except about 1/8" taller. File a notch in the new rear sight blade. Polish the blade and add cold blue.

It will now probably shoot too high, and you will need to install a new front sight.

Dang. That's beyond my skill level. I was hoping I might be able to wedge shims or something under the rear portion of the sight, but not sure if there is enough flex in the sight base.

Here is a picture of the sight that came on my carbine.

http://uploads.tapatalk-cdn.com/20160713/8519ef0067c8db28882e6d651592ea0e.jpg

[Tatume]

You might contact GoodSteel, who has a reputation on this list as a good and fair-minded gunsmith.

[Tom Myers]

Dang. That's beyond my skill level. I was hoping I might be able to wedge shims or something under the rear portion of the sight, but not sure if there is enough flex in the sight base.

Here is a picture of the sight that came on my carbine.

http://uploads.tapatalk-cdn.com/20160713/8519ef0067c8db28882e6d651592ea0e.jpg

Before attempting to permantly alter your sight, you might locate a thin piece of steel. Determine how much more height you need and then file it to the shape shown in the image below. Epoxy the insert in place and, If it works, you could then have it soldered in place and blue it.


172275

[pietro]

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If the rear sight's long leaf is a bit flexible, a thin BCS (beer can shim) can be slipped under it, as not much additional elevation will be needed to achieve zero.


If that isn't workable, I would cut/file a 1/2"x1/2"x1/16" slab of steel until it looks like the rear sight notch (from the shooting position/rear), and just epoxy it to the rear face of the existing rear sight blade/notch. (you'll most likely need to add less than an additional .10" to the existing rear sight height)

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[Tom Myers]

.

If the rear sight's long leaf is a bit flexible, a thin BCS (beer can shim) can be slipped under it, as not much additional elevation will be needed to achieve zero.


If that isn't workable, I would cut/file a 1/2"x1/2"x1/16" slab of steel until it looks like the rear sight notch (from the shooting position/rear), and just epoxy it to the rear face of the existing rear sight blade/notch. (you'll most likely need to add less than an additional .10" to the existing rear sight height)

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Pietro,
It appears that great minds think alike:bigsmyl2:.
However, I am wondering if placing the insert on the rear of the sight would allow enough clearance when the ladder is flipped up. That is why I suggested that the insert be placed on the front face of the existing notch.
That will probably be determined at the time of the alteration.

[2ndAmendmentNut]

I am going to try shims and see how that goes. If the shims don't work I will replace the sight with a Marbles semi-buckhorn style sight.

[2ndAmendmentNut]

Just to provide some follow up, I attempted to zero the original sight at 100yards with shims without success. I then replaced the sight with a Marbles Semi-buck horn style but found I could not accurately aim with the sight. I decided to go back to the original ladder style and found the filed front sight worked perfectly for a 6 o'clock bulls-eye at 50 yards. The sight when flipped up and the elevator set at the bottom also allows for a perfect 6 o'clock bulls-eye minute of milk jug at 100 yards. On my next outing I will try to learn which elevation notches allow for 200 and 300 yard shooting.

[Scharfschuetze]

Looks like you solved your problem already.

If you encounter it again, you might be able to make up that 4" elevation issue by going to a heavier boolit. Order some before buying a mold and see if that solves your issue.

Another easy fix would be to order a dovetail filler from one of the larger gun supply firms. Remove your current rear sight, slide in the filler and then drill and tap it and then fit your current sight to it with a screw. Should work a treat for you and you won't have to modify your factory sight other than drilling a hole through through the base for the screw.

I'm guessing your sight radius is about 20" so given that, you'll need to raise that rear sight about .024 inches for 4 inches.

Knowing that, you can measure the distance between the notches on the ladder and determine an MOA value per notch when each MOA is about .006 inches. Compare your values to a trajectory table for your load and then you'll be pretty close to determining what ranges the ladder is calibrated for.