Aligning scope to bore parallel?????

Dusty Stevens said:
I have never had this issue in benchrest:confused:
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Unless you shoot multiple ranges (distances, not locations :D I'm guessing you shoot other places than just Benton :D) with the same rifle, you won't. Many rail guns have the scope mounted off to the side by a noticeable distance.
It can come into play in silhouette shooting though, and varminting where the distances vary from shot to shot.

As for laser alignment, use a boresight laser instead of shooting and still use the practice I described - aiming at vertical lines at two separate ranges. Either way , once you have the mounts in alignment, you still have to mount the scope with the adjustment travel in line with this alignment. I guess it would give you the chance to be sure that the reticle is in alignment with the adjustment travel. :D

The reticle is mounted separate of the erector tube in most scopes.
 
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Would this work? Insert a laser in the bore. Hang a weighted string, so it is perfectly vertical, about 30 to 50 feet away. Aim the laser so it hits the string and then projects on another more distant target, like 50-100 yards. If the center of the scope reticule hits the string and the distant laser point, it will be alligned.
 
JeffL said:
Would this work? Insert a laser in the bore. Hang a weighted string, so it is perfectly vertical, about 30 to 50 feet away. Aim the laser so it hits the string and then projects on another more distant target, like 50-100 yards. If the center of the scope reticule hits the string and the distant laser point, it will be alligned.
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That should get you there. Thanks for the simplification. Provided that the scope was optically centered to begin with. You could then run the elevation adjustment up/down to verify that the reticle is indeed inline with the adjuster.
 
I will have to study this for a while, but I think it may explain something I have been observing for years. Very interesting indeed. The pieces of the puzzle continue to fall in place. Keep the feedback coming.

Gene Beggs
 
Could one also turn the scope 90 deg and run the vertical up and down to check it?
 
JeffL said:
Could one also turn the scope 90 deg and run the vertical up and down to check it?
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People with steep ejecting rifles have been running scopes mounted at 90° for years. You just have to remember that the turret marked "U/D" is now windage, and the one marked L/R is now elevation. And in some scopes the range of adjustment may vary between the two. But just to check linearity? Sure why not. (You have my permission to do so. :D Like you needed it :D)
You would also probably need to redo the optical centering between tests.
 
Gene Beggs said:
I will have to study this for a while, but I think it may explain something I have been observing for years. Very interesting indeed. The pieces of the puzzle continue to fall in place. Keep the feedback coming.

Gene Beggs
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Gene
I"m curious what it is that you have been observing.
 
JeffL said:
Could one also turn the scope 90 deg and run the vertical up and down to check it?
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I have seen Boyer rotate a scope in the rings to see if the reticle is in the center. What does that help??? Dunno!! This was on a Farley where the scope bases bolt on.

Viewing from the vertical plane, the only scope mountings that would not be parallel to the bore probably would be on some of the old actions (Mauser 98's etc) where the scope base screw holes were drilled without a jig or milling machine setup and were off center in different directions.

The right hand spin of a right hand twist barrel will take the bullet out of the vertical zero. I have a 6mm on a Panda, that at 600 yards, and the horizontal drift due to twist is about 2".

Now, gun cant is another story.
 
Verticle Reticle Instrument

RoyB:
I use the Verticle Reticle Instrument you mention and believe it to be a "must have" for accurate hunting rifles (the kind of sporter that may be employed at 400-plus yards) and long-range rifles shot at varying distances and from rests other than front rests and bags used in competition -- but I should add that I almost always employ some type of level (indicating side-to side cant) mounted on the scope or mounting system. It's certainly not a cure-all, and its usefulness, for my purposes, is minimal until extended ranges are involved, and then one's wind reading and adjusting abilities, as usual, are the primary issue.
Well, maybe "must have" is a bit too strong, and I've been wrong before. And there's certainly other noise that is heard, such the bullet spin Mr. Sharrret refers to, that may drown out the noise I'm trying to muzzle. And maybe all the gizmo does on a factory gun is help get the reticle reasonably "vertical" to the bore (right angles being less common in some reticles than one would hope). I wll say that Remington doesn't always drill their mount holes with sufficient precision.
For known-and-constant-range competition rifles shot off very stable (and therefore repeatable) rests it may not be a big issue -- I dunno. But I have that gizmo, and I use it, and it adds to my confidence in my long-range shooting and hunting abilities.
 
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Thanks Folks! Great conversation.............

Most, if not all Remington actions I've ever measured have the scope mounting holes off center to the bore of the action.

Savage actions tend to be spot on. I've also had all kinds of off center problems with Ruger rifles...

Currently, I use nothing but Millett Angle Locs, Nikon or SK Kontour rings and mounts because they all offer both front AND rear windage adjustment.....

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But does it prove anything in the end?

I have a rifle I shoot 200SMKs & 210 SMKs & Bergers thru & the 210s print 3 inches to the right of of the 200s at 100 yards, but once zeroed at theat distance for either, my 1200 yard zeros are consistent with the short range strike (as wel as you can judge in such circumstances), though I'm certain enough to make alterations & expect a centre hit when the flags cross the pole.
 
Don, A columnated beam

Gunner223 said:
A Sweeney columnator works well for me. I have been using one for many years.

Don
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is what I spend my days striving for. I build particle analyzers that utilize three lasers. This focus parameter is a must for our product to measure accurately. This also explains my log on. Could you describe your set up? I could probably implement it at work. One can sure tell it's winter, can he not? Thanks

LASER
 
JeffL said:
Gene
I"m curious what it is that you have been observing.
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Jeff, after studying about it, I do not believe this is related to what I was thinking about.

When I first got involved in this obsession called benchrest back in 1988, my first rifle exhibited a trait that I have yet to understand. The rifle was a Hall sporter in a Hall stock built by James Messer with a Hart 13 twist LV barrel and a Leu 36 scope. At the time, I did not realize just how good it was, but have since realaized, I had a real jewel!

My mentors, Charles Huckeba and Cecil Tucker advised me to put that barrel away and save it for the big matches, but, ignoring their sage advice, I foolishly burned it out in about a year. Here's what it would do.

Let's say you have four shots in a dot, when the condition goes away and will not come back. Time is running out and you know you are going to have to fire a sighter and hold off. With that rifle, you could go to the sighter, hold the same point of aim used with the preceeding four shots and fire the shot, then place the dot back on the point of aim and carefully, without disturbing the rifle in the bags, move the dot over to the bullet hole with the scope turrets. You could then go back to the record, hold on the GROUP and that shot would go right into the hole every time! It was the damndest thing I ever saw; it would do it every time, and I have not had a rifle since that would. Oh, I have had several barrels that were very accurate; one that even earned a couple of HOF points for me, but I have never had a rifle/scope setup that would duplicate the behavior of that first rifle. It now belongs to a friend of mine, Street Rogers, a captain for America West airlines who lives near El Paso.

Some would say, "Well, you're just disturbing the rifle when you make your scope adjustment." but I don't think so; I have even tried it with a rail gun. Others may say, "Well,, you're not firing the two shots in the same condition; you're missing a change, and that's what's causing the shot to go astray."

For years, I have thought about this and have yet to understand it. I have also tried it in the tunnel and it will not work there either. It seems simple; you put the dot on the point of aim, fire the shot and tweak the crosshair over to the bullet hole. If the rifle is shooting, the next shot should strike precisely at the point of aim, but it rarely does. It seems that the scope adjustment always results in about twice the change in point of impact as I expect. Anyone got any ideas about this?

Gene Beggs
 
Gene Beggs said:
For years, I have thought about this and have yet to understand it. I have also tried it in the tunnel and it will not work there either. It seems simple; you put the dot on the point of aim, fire the shot and tweak the crosshair over to the bullet hole. If the rifle is shooting, the next shot should strike precisely at the point of aim, but it rarely does. It seems that the scope adjustment always results in about twice the change in point of impact as I expect. Anyone got any ideas about this?

Gene Beggs
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Gene, one thing that may effect your exercise of clicking over, I think most times when we hold off, we hold too much. i.e. What looks like a bullet and a half change on the sighter, I think we end up holding 2-1/2 holes.

How many times have you heard someone say "I held xxxx and it went exactly where I held"? In the instance where you clicked over was an exact amount of where you held versus where the bullet actually went not what our mind pictures it.
 
Jerry, what I have always done is the same thing we do when sighting in any scope sighted rifle. i.e., hold a precise point of aim (I center the dot in the mothball), fire the shot then place the rifle back on the point of aim as when you fired the sighter, which in this case would be center the dot in the mothball. If the bullet hole is say high and left, carefully move the dot with the turrets until it comes to rest directly over the bullet hole. All this without disturbing the rifle in the bags. This should, theoretically, bring the point of impact perfectly in line with point of aim. Like I said, in spite of my best efforts, I have been unable to duplicate what I experienced with that first Hall sporter.

Gene Beggs
 
Gene Beggs said:
Jerry, what I have always done is the same thing we do when sighting in any scope sighted rifle. i.e., hold a precise point of aim (I center the dot in the mothball), fire the shot then place the rifle back on the point of aim as when you fired the sighter, which in this case would be center the dot in the mothball. If the bullet hole is say high and left, carefully move the dot with the turrets until it comes to rest directly over the bullet hole. All this without disturbing the rifle in the bags. This should, theoretically, bring the point of impact perfectly in line with point of aim. Like I said, in spite of my best efforts, I have been unable to duplicate what I experienced with that first Hall sporter.

Gene Beggs
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Hi Gene,

That tells me you are having a "sighter to record target" change that is occuring due to angular differences to the gun as it is positioned differently on the 2 different targets, which can make for oscillation differences or bag reaction differences.

Notice, that if you make these same target/scope adjustment changes during a practice target shooting session, with a practice target that has multiple bullseye aimpoints located horizontally within a couple of inches of each other..............the impact change will be non-existent or almost unnoticable with a scope adjustment change for new wind condition, at least it has for me.

Like you, Ive seen where some guns have a greater "sighter/record target" reaction than others and I have not been able to determine what the causation factor is for those guns that handle this change better...................Don
 
Gene Beggs said:
I have been unable to duplicate what I experienced with that first Hall sporter.

Gene Beggs
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Now Street has that Hall and he has a nice South Bend Heavy 10. He must be blessed!

I've noticed many times with rimfire BR that the POI changes greatly when moving from a centerfire group targets sighter target to the record target. And this is at 50 yards & 50 meters. Just the change of how the stock contacts the bags when moving up and down seems to cause this.

In shooting rimfire score, changing from one row to the next will many times invoke a POI change. Some of the rimfire score organizations like ARA have a sighter bull outside of each end of each row.
 
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