Question about scopes...
- Thread starter Epyon
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Art Eatman
Staff in Memoriam
" How do you align your scope with your barrel to be accurate?"
Basic alignment comes from factory-emplaced screw holes for the mounts' screws. Then, "boresighting", where you look through the bore and center some object at a distance--and work the scope's adjustments until the crosshairs and the centered object coincide. The next step is the fine tuning on targets, adjusting the scope as necessary.
"Does adjusting for far distances mean that if you take a close shot your aim will be off?"
No. Might be a little bit of blur or some parallax (look it up in Wikipedia) but not enough to really matter.
"What does eye relief mean?"
The distance from the back end of the scope to you eye. Bigger is better. Too little eye relief and a heavy recoiling rifle can mean a "bloused eyebrow", a half-moon cut above the eye. Roughly, 3" to 4" is common.
Art
Basic alignment comes from factory-emplaced screw holes for the mounts' screws. Then, "boresighting", where you look through the bore and center some object at a distance--and work the scope's adjustments until the crosshairs and the centered object coincide. The next step is the fine tuning on targets, adjusting the scope as necessary.
"Does adjusting for far distances mean that if you take a close shot your aim will be off?"
No. Might be a little bit of blur or some parallax (look it up in Wikipedia) but not enough to really matter.
"What does eye relief mean?"
The distance from the back end of the scope to you eye. Bigger is better. Too little eye relief and a heavy recoiling rifle can mean a "bloused eyebrow", a half-moon cut above the eye. Roughly, 3" to 4" is common.
Art
wolverine350
New member
Art said it all 
Depends on what you mean. If you are referring to the trajectory of the bullet then yes, but probably not enough to matter. Typically you will sight the rifle in so that you can hold for the center of your game animal and hit in the kill area out to some distance. For example with most standard deer hunting rounds if you sight it in so it hits about 1.5 inches above the point of aim at 100 yards you can hold for the center of a deer's chest from contact distance out to at least 200 yards and expect to hit it in the chest, just like you would do with iron sights. If you mean focusing clearly then you will probably have some blurring up close. Keep both eyes open and you won't have a problem.
Eye relief is how far from the eyepiece lens you have to have your eye to see the full view in the scope. Eye relief typically has a range of several inches which is good because changing from summer to winter clothes can add an inch or more to the length of pull on the rilfe. Variable scopes will have a different eye relief range at each magnification. If you are outside that range you will not see the full field in the eyepiece lens. More eye relief is not always better especially with standard hunting rounds. I have had problems on a number of rifles when I picked a low powered scope with such a long eye relief that the standard mounts would not allow me to achieve correct eye relief when I shouldered the rifle. IOW I couldn't mount the scope far enough forward to use the scope without going to some funny looking extended scope rings. I have a 2-7x Nikon Monarch on a rifle and if I turn the scope down below the 3x mark on the adjustment ring the eye relief is too long so I have to leave it set on 3x. I could spend more money on a mounting rail that extends 1 inch farther forward and that would solve the problem but the last time I looked for one the only one I found was intended for police snipers and cost over $100 for the mount alone. I wouldn't worry about the eye relief being too short on a .243, but I would on a .338 Win. mag.
Another thing to consider is how high you mount your scope. A test to see if the scope height and eye relief are set correctly for YOU on that particular rifle is to pick an object some distance away. The 100 yard target frame at the shooting range will work. Stand facing the target frame while holding your rifle like you typically would while hunting. If you are at a shooting range make sure this doesn't violate some rule they have. If you want to do this at home try not to scare the neighbors. Close your eyes. While keeping your eyes closed bring your rifle to your shoulder and put your cheek on the stock where it feels right. Then open your eyes. You should have the target frame more or less centered in the scope and you should see the full field in the scope without having to move your head on the rifle. You should see the full field of view in the scope without doing anything else. Do this several times. Try it with your typical hunting clothes on because a heavy coat will change the length of pull of the rifle. If you have to move your head on the rifle to see properly through the scope then either the scope height is wrong for you or you need to move the scope forward or backward to get it in the correct eye relief range. Most people who claim that scopes are slow or difficult to use have never tried this and their scope is not positioned correctly for them on their rifle. You may have to try several different height rings to find ones that are right for you.
MeekAndMild
New member
Two other considerations: shims and an adjustable scope base.
It is a good thing to start the scope alignment process by shooting at a huge target, maybe 24 inches square at 25 yards. Then rather than using the knobs, use shims to close the vertical gap between the aim point and bullet impact point. (An acceptable 0.0025 inch shim can be cut from an aluminum coca cola can, two of which which will change the point of impact about 1 and 1/4 inch* at 25 yards.) Shim the bottom of the ring but not the top. Once the scope is shimmed with one or 2 of these it will reduce the need to use the vertical knob. I generally start with 1 shim under the back end of the scope and will use up to 4.
Horizontal movement can be done with the screws on the adjustable base, to move the scope from side to side.
Then once these 2 steps are done and the bullet is impacting where it needs to go at 25 yards the process can be repeated at 100 yards. Once I get it within 3 or 4 inches at 100 yards using shims and the base screws then I take it all apart and put Loctite on the mounting screws and shims, let it sit for a day or so and then check tightness again. I also have no qualms about putting a drop of Loctite on the bottom of the scope in whichever ring isn't shimmed.
All this can be done while breaking in the barrel, which makes it a little less boring. THEN is the time to sight in using the scope knobs.
(If a person doesn't want to do all this or if they need more than 2-4 shims Burris makes adjustable rings with inserts that do the same thing easier, faster and with more stability.)
*edited to reflect what I usually do to raise the aim point.
It is a good thing to start the scope alignment process by shooting at a huge target, maybe 24 inches square at 25 yards. Then rather than using the knobs, use shims to close the vertical gap between the aim point and bullet impact point. (An acceptable 0.0025 inch shim can be cut from an aluminum coca cola can, two of which which will change the point of impact about 1 and 1/4 inch* at 25 yards.) Shim the bottom of the ring but not the top. Once the scope is shimmed with one or 2 of these it will reduce the need to use the vertical knob. I generally start with 1 shim under the back end of the scope and will use up to 4.
Horizontal movement can be done with the screws on the adjustable base, to move the scope from side to side.
Then once these 2 steps are done and the bullet is impacting where it needs to go at 25 yards the process can be repeated at 100 yards. Once I get it within 3 or 4 inches at 100 yards using shims and the base screws then I take it all apart and put Loctite on the mounting screws and shims, let it sit for a day or so and then check tightness again. I also have no qualms about putting a drop of Loctite on the bottom of the scope in whichever ring isn't shimmed.
All this can be done while breaking in the barrel, which makes it a little less boring. THEN is the time to sight in using the scope knobs.
(If a person doesn't want to do all this or if they need more than 2-4 shims Burris makes adjustable rings with inserts that do the same thing easier, faster and with more stability.)
*edited to reflect what I usually do to raise the aim point.
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Good tip on starting at 25 yards. I've found that if I'm on for elevation or a little low at 25 I'm close at 100 - no more wondering which side of the target I missed on.
Instead of shims, if you have a Weaver/picatinny rail you can use windage adjustable rings if you need to. I haven't seen a problem with this recently. I suspect improved tolerances in machining and placing the d&t holes have a lot to do with it.
Instead of shims, if you have a Weaver/picatinny rail you can use windage adjustable rings if you need to. I haven't seen a problem with this recently. I suspect improved tolerances in machining and placing the d&t holes have a lot to do with it.