Help me with a calculation
Have I figured this correctly?
I have a 22 mag. rifle that shoots 13" low at 35 yards. The scope rings are 3-1/2" apart. My calculation is to put a .036" shim under the rear scope ring (raising the back of the scope) to bring the point of impact back to center...I think.
I am using country boy arithmetic--it's all I know. I do vaguely recall a course where we solved x, but it's been way too many years ago.
Thanks,
Rafter-S
"What is truth? No wonder jesting Pilate turned away. The truth, it has a thousand faces -- show only one of them, and the whole truth flies away! But how to show the whole? That is the question."
--Thomas Wolfe, "You Can't Go Home Again" (1934)
I have a 22 mag. rifle that shoots 13" low at 35 yards. The scope rings are 3-1/2" apart. My calculation is to put a .036" shim under the rear scope ring (raising the back of the scope) to bring the point of impact back to center...I think.
I am using country boy arithmetic--it's all I know. I do vaguely recall a course where we solved x, but it's been way too many years ago.
Thanks,
Rafter-S
"What is truth? No wonder jesting Pilate turned away. The truth, it has a thousand faces -- show only one of them, and the whole truth flies away! But how to show the whole? That is the question."
--Thomas Wolfe, "You Can't Go Home Again" (1934)
0
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If you put a .036" shim under the scope - with 3?" between the scoperings...
You will change the angle - as you want to, with .036" per 3?".
Convert the 35 yards to inches and divide it by the 3?".
Then multiply it with the .036" - then you have the change of Zero at 35 yards.
(Theoretically)
Don't do anything that I've allready done - That'd be just plain STOOOOOOPID.0 -
In answer to your question, Your close enough for the 22 mags trajectory.
Some ???'s
? #1. What kind of mounting system are you using?
? #2.How high are the rings?
Measure from the base top to the circle of the bottom of the ring.
? #3. How much adjustment have you used of the Windage?
? #4. Same as #3, but for Elevation?
? #5. What scope are you using?
Happy Bullet Holes!0 -
The rifle is a stainless Ruger 77/22 magnum. I've used 2 different Leupold scopes, switched the rings (front to back and back to front), cleaned and deburred all around the V-block. It still prints 13" low at 35 yards. Scopes are set on dead zero (center of adjustment). I believe the barrel suffers from extreme runout.
Requiring that much elevation adjustment on the scope, it is obviously an manufacturing problem.
I called Ruger and they said to send in the rifle. They would repair it or make it right. Being a new rifle, they are also picking up the shipping both ways.
I could solve the problem with shims under the scope mounts, but I don't want to start out with a rifle that nice with shimming and improvising. It ought to be "right."
Thanks for your help and suggestions,
Rafter-S
"What is truth? No wonder jesting Pilate turned away. The truth, it has a thousand faces -- show only one of them, and the whole truth flies away! But how to show the whole? That is the question."
--Thomas Wolfe, "You Can't Go Home Again" (1934)0 -
Well, you're making the assumption that the bullet's flight path approximates a straight line in its drop from leaving the barrel---not entirely correct, given the true effect of gravity, which bends the bullet's flight path into (essentially) a parabola. However, not knowing how fast your .22 bullet goes, it's probably not too bad an approach as a first approximation. And it has the added advantage that, unlike the (supposedly) more accurate "physics" approach, you don't need to know your bullet's muzzle velocity and initial angle of elevation.... 0 -
Ruger will make it right! But, if you don't want to send it back, and you don't mind adding a pressure point between Stock and Barrel. This Little Trick will make the rifle shoot the bullet, any bullet. It doesn't detract from the rifle if done properly, and is relatively simple. This system was used by Expert Marksmen back in the days when 52 Bs were Advancing toward Legendary Status.
get a 3/16th drill bit, drill two holes about 1 inch from the forward end of the stock, at about 33 degrees from centerline. In otherwords, one on the bottom left side and one on the bottom right side, the angle is not terribly important. Tap the holes with a Standard Thread 1/4 -20 tap, add set screws. Tension as needed. Assuming you are using Ruger Rings and haven't put them on backward, or Mixed the rings with Model 77 Rings (which are two different heights). Adding Barrel pressure is as good or better than Glass Bedding the Barrel, Glass Bedded Barrels are not adjustable. Now! If you want to Glass Bed the Action, I would totally agree. How accurate do you want this gun? ~You do know: It will shoot with the 17HMR all day long, if you use the Ballistic Tip, or Remington Rounds (with the actual Jacketed Bullet and Moly Coat them with spray Moly), the Magnum becomes very formitable.
Ronnie G. Perkins0 -
Let Ruger make it right.
A person should not have to go to such extremes to make
a quality gun shoot where it's supposed to.
My 2.5 cents worth.
JOIN THE NRA
SUPPORT THE NRA
NRA Benefactor Life Member0 -
Delta514.......drill two holes in what???
"The only thing necessary for the triumph of evil is for good men to do nothing."
Edmund Burke0 -
Rafter, sure the shim job will bring in your zero ???? But what if it just sheds light on another problem? I think you have the right idea along with alot of the other posts, send it back and get a rifle that is correct. It is too nice of a rifle to make it a rigged unit.
Good luck DD2B0 -
I read that you're shooting and expecting to be, 'dead on target' without any adjustments.
If that is so, and it does happen, it's one in a million 'shot'.
There are so many variables that affect things, and just the fact that the scope is above bore line at '0' settings will greatly make a difference,...for any gun.
In reality, when adjusting a scope, we are making the reticle see & point to where the bullet hits. Ie., where the gun shoots.
You will have to adjust the scope. If I'm reading your post right(?).
BEFORE you go doing anything else, and just in case I'm not, or what you wrote isn't what you meant, the following are another variables.
Don't think its the stock-bedding at that distance.
> Check muzzle bore for concentricity, and damage. If there return to Ruger.
> Scope function correctly
> Ring alignment. Install rings on rifle without scope.
Eyeball ring sides, and especially the inside bottoms of the F & R ring alignment. Are they parallel? Are they level? "Square" to each other?
If the front ring is higher than the back, there'a an elevation problem with the receiver, ring, and/or mounting technique.
If skewed any any of the three axis, it's a mounting problem.
> If a variable scope, look at the target, rifle FIRMLY held still, rotate the power ring without moving the rifle. If the reticle/target move,..it's the scope.
If it doesn't move, loosen each ring cap screw 1/2 turn. Recheck.
Then another 1/2 turn (1 turn total). Recheck.
If any movement, it's internal stress of the scope.
Caused by rings, receiver, and/or bad scope. Cheaper scopes are very easy to "stress". Many have multi piece construction tube assembly.
> Same scenerio as above, try to wiggle the back part(eyepiece) of
the scope. If it moves at all,...it's the scope.
Happy Bullet Holes!0
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