Zero/Setup iron sights on Drilling

[jcf1]

Have run through a few loads today on the new drilling, and would appreciate others experience on zeroing with fixed iron sights. Currently it seems to be shooting high and right, but need some further time to attempt a group properly to allow for decent barrel cooling time.

What I would like to know is what range others tend to set up their iron sights, and also any tips for adjustment for windage and/or elevation? I appreciate this will probably require careful filing of the notch or post accordingly? Any basic guides based on experience appreciated. I do not currently have a scope on the gun, and would be intending to primarily use it with open sights in the field.

[mike ford]

jcf1,
You didn't say how high the drilling is shooting, nor at what range. They were normally sighted for whatever distance allowed by the range available to the company. This was often less than 100 meters; not knowing the actual distance, I suggest trying it at 80 meters. If it shoots high, but not so high that it caused you to miss a deer, I wouldn't worry about it. For most calibers I sight mine to shoot about 2 inches high at 100 yards( or sometimes meters). This allows me to hold "dead on" at any range I am likely to shoot a deer. I admit, however, that the drillings I use have scopes and I would not shoot open sights to nearly the distance that I would a scope. The principle is still the same, however. You can adjust the point of impact, some, by adjusting the load. The change is indeterminate, so you will have to try the new load to see where it shoots. You are absolutely correct to allow the barrel to cool after each shoot. As far as shooting to the right is concerned, I suggest waiting until the elevation is worked out, as best you can. Changing the load for elevation, might also have an effect on the "windage". I would only file the rear sight if there were no other way to bring the point of impact to an acceptable place. If you file it and decide you don't like it, it would be difficult to change back. A new one can be had, but it might be quicker and easier to file one out by hand. I hope you find this useful, if someone else offers different advice, you might try theirs first( except filing the sight, which should always be the last resort).
Mike

[sharps4590]

I generally shoot my open sighted guns at 50 yards. For where I hunt 75 yards would be a fairly long shot. Usually I can find a load that shoots to the sights. Windage should be drift adjustable. More often than not I will open up the "U" notch a bit with a needle file in an effort to get more light around the bead. Obviously that is providing the firearm is equipped with the "U" notch and round bead. I have never filed a rear sight to adjust elevation and as Mike mentioned I don't believe it a good idea. For the very few times I've needed to adjust elevation what I've done is either make or have made a taller or shorter front sight then file it in, saving the original for posterity. I don't recall that I've ever needed a shorter front sight. Once everything is settled on for 50 yards I'll try it at 75 and 100 yards. With the slow poke cartridges I usually shoot at 75 yards little or no correction is needed in sight picture. At 100 yards that isn't ordinarily the case. That's just what I do and it works for me and where I hunt.

[Leatherman]

I agree with Mike we need to know what type of rear and front sights you have on your rifle , ( pictures) then we can better advise you what can be done. There are front sights available in different heights that we may be able to point you to depending on the style. I would try to work up a load first that gets you closest to the sights as they are. It was originally sighted to a load that you need to figure out the bullet weight and velocity. What is the caliber?

[jcf1]

Thanks folks. They are 26" barrels. Its an 8x57 IR. I have worked up 3 loads that shoot a 196gr SP at 2275, 2550 and 2650fps for 3 successively heavier powder charges. I'm using IMR 4064.

Pics of the sights - its a typical flip up leaf with silvered front bead:

IMG_20160331_083422.jpgIMG_20160331_083356.jpg

[jcf1]

Also - rifle barrel is marked 13g (so I'm guessing regulated for 200gr loads). Only .318 rounds I can find anywhere are all 196 - so that's that!

[jcf1]

Have also just slugged the barrel. It is marked 7.8mm - so would expect a .318. I am getting .320-.321 from my measurements. So - should I be sticking with .318?

[sharps4590]

IMR-4064 should be a good powder for that cartridge. Do all three loads shoot to the same POI? Generally a lighter bullet or faster load will shoot lower but, as with all things "rifle", nothing is 100%, 100% of the time. As Mike always advises if a .323 bullet will fit into the mouth/neck of a fired case I believe I would be using .323. For that type of front sight my local gunsmith machined out two front sights of differing heights. Once I decided on the loads, or rather the rifle decided for me, one jacketed and one cast, I filed them in for elevation then hand filed them to a bead configuration. As I shoot about 95% cast it's probable the front sight for the jacketed load will never be re-installed. Anything can be overcome, just takes some time and fiddlin' with it.

[jcf1]

Hard to tell if they all shoot to the same POI yet, as I haven't yet done a proper run on cooled barrel. Measuring the inside of the case mouth gives me about .3195 so I'm guessing sticking with the 318 is the way to go.

[mike ford]

jcf1,
It seems to me that you are coming along very well with your project. It is hard to measure the inside diameter of a fired case, unless you have a set of small hole gauges or plug gauges ( I find the small "flats" on the inside jaws of calipers and difficulty of centering them causes me one or more thousandths error).Using a bullet as a plug gauge, on the other hand, is quick and easy. It is not necessary to know the precise diameter, only if the bullet fits in or doesn't. If this were my project, I would be pretty excited to try the new 165 gr Flex Tip 32 Win. Spec. bullets , for the Leverevolution ammo( even sized to fit).
Mike

[Leatherman]

I believe Brownells sells that style of front sight in different heights. It may still need to be filed to fit the slot in your rifles rib.

[Leatherman]

Is your front scope mount forward of your rear sight?

[jcf1]

Yes it is.

[Leatherman]

In that case it was originally mounted with a long modern German scope most likely with the bar entigrated in the tube and front objective that the claw bases are mounted to the scope with screws. I don't know what these types are called I am sure they have a name.

[mike ford]

The bar (rail) is a Prismaschiene. Lower powered Aluminum scopes usually have one rail on the tube. Higher powered/variable powered aluminum scopes usually have two, one on the tube and one on the objective bell.
Mike