Okay here's my question about rifle canting. If I believe that my rifle is perfectly straight meaning not canted when mounting my scope then why do I feel or why does it feel not level when holding/shouldering it? The way I did mine was since I have a Pro Sport, I put a torpedo level on the cocking lever which is in the open cocking position. And then I use a Plumb line and leveled my scope that way then added a scope level to the scopes tube body. My issue is is that whenever i hold/shoulder the rifle to what "i feel" is level, its totally skewed in the scope and scope bubble level. So i am wondering if i should level the scope to the rifle as if i were holding it to what i feel is level then level the scope or just let it be?
imho, you're not leveling correctly. When looking at rifle cant you are checking to make sure that the center of the scope is exactly vertical to the center of the barrel. In order to do this you need to only check the barrel and the scope centerline. The only tool I know of to do this correctly is this...
https://shop.brownells.com/gunsmith-tools-supplies/sight-scope-installation-tools/scope-reticle-levelers/vertical-reticle-instrument-sku289100000-6097-14989.aspx
You then hang a pumb line and make sure your cross hairs are level.
Place a target out at 10 -15 yards indoors. draw a line on it that is perfectly plumb and put a small dot in the middle of the line. Now shoot at the dot with the scope elevation full up and full down. While doing this hold the vertical line on your reticle in exact alignment with the plumb line you drew on the target.
If your groups fall on the plumb line, you're properly leveled. If not, rotate your scope to correct.
Once you're set up, put a bubble level on the scope tube and level it with your vertical reticle crosshair on the plumb line.
Then believe your bubble level. Your brain will adjust.
Knobs
Can someone tell me if my following statement is wrong? I sometimes get confused by the scope levelling process detailed in many sources.
If I align the reticle of the scope such that a line extending through it bisects the barrel-- assumed to have circular cross section-- and then I align the reticle to a plumb line ( i.e to the actual vertical given by gravity), then it is immaterial whether I level the scope the to the top of the receiver/ action as long as I always align the reticle of the scope with the vertical due to gravity.
And if I verify this by doing what Knobs above has detailed then I shouldn't have to worry about levelling the scope with the action.
All the scope mounting procedure I have read of starts by levelling the scope to the action, and there are lots of products which have two levels, and surely they can't be wrong, but I can't find where I am going wrong in my understanding as explained above.
I suspect I am missing something really obvious, but can't put my finger on it!
Can someone tell me if my following statement is wrong? I sometimes get confused by the scope levelling process detailed in many sources.
If I align the reticle of the scope such that a line extending through it bisects the barrel-- assumed to have circular cross section-- and then I align the reticle to a plumb line ( i.e to the actual vertical given by gravity), then it is immaterial whether I level the scope the to the top of the receiver/ action as long as I always align the reticle of the scope with the vertical due to gravity.
And if I verify this by doing what Knobs above has detailed then I shouldn't have to worry about levelling the scope with the action.
All the scope mounting procedure I have read of starts by levelling the scope to the action, and there are lots of products which have two levels, and surely they can't be wrong, but I can't find where I am going wrong in my understanding as explained above.
I suspect I am missing something really obvious, but can't put my finger on it!
“If I align the reticle of the scope such that a line extending through it bisects the barrel-- assumed to have circular cross section-- and then I align the reticle to a plumb line ( i.e to the actual vertical given by gravity), then it is immaterial whether I level the scope the to the top of the receiver/ action as long as I always align the reticle of the scope with the vertical due to gravity.”
You got it.
“And if I verify this by doing what Knobs above has detailed then I shouldn't have to worry about levelling the scope with the action.”
Yes, that is the acid test. Though I do it outdoors. Zero at apex (23-30yds) and verify alignment at 10 yards.
“All the scope mounting procedure I have read of starts by levelling the scope to the action, and there are lots of products which have two levels, and surely they can't be wrong, but I can't find where I am going wrong in my understanding as explained above.”
Sure they can be wrong. All manufactured items have allowable tolerances – receivers, barrels, scopes, mounts. If you make assumptions about what those are, you are at the mercy of those manufacturing tolerances when you setup your scope. Those so-called alignment tools that go off the receiver will likely get you in the ballpark, and might be close enough if you are lucky. I prefer to get it right and not rely on luck.
Can someone tell me if my following statement is wrong? I sometimes get confused by the scope levelling process detailed in many sources.
If I align the reticle of the scope such that a line extending through it bisects the barrel-- assumed to have circular cross section-- and then I align the reticle to a plumb line ( i.e to the actual vertical given by gravity), then it is immaterial whether I level the scope the to the top of the receiver/ action as long as I always align the reticle of the scope with the vertical due to gravity.
And if I verify this by doing what Knobs above has detailed then I shouldn't have to worry about levelling the scope with the action.
All the scope mounting procedure I have read of starts by levelling the scope to the action, and there are lots of products which have two levels, and surely they can't be wrong, but I can't find where I am going wrong in my understanding as explained above.
I suspect I am missing something really obvious, but can't put my finger on it!
“If I align the reticle of the scope such that a line extending through it bisects the barrel-- assumed to have circular cross section-- and then I align the reticle to a plumb line ( i.e to the actual vertical given by gravity), then it is immaterial whether I level the scope the to the top of the receiver/ action as long as I always align the reticle of the scope with the vertical due to gravity.”
You got it.“And if I verify this by doing what Knobs above has detailed then I shouldn't have to worry about levelling the scope with the action.”
Yes, that is the acid test. Though I do it outdoors. Zero at apex (23-30yds) and verify alignment at 10 yards.“All the scope mounting procedure I have read of starts by levelling the scope to the action, and there are lots of products which have two levels, and surely they can't be wrong, but I can't find where I am going wrong in my understanding as explained above.”
Sure they can be wrong. All manufactured items have allowable tolerances – receivers, barrels, scopes, mounts. If you make assumptions about what those are, you are at the mercy of those manufacturing tolerances when you setup your scope. Those so-called alignment tools that go off the receiver will likely get you in the ballpark, and might be close enough if you are lucky. I prefer to get it right and not rely on luck.
Thanks very much. That was very helpful.
I suspect I am missing something really obvious, but can't put my finger on it!
No, you're not missing much.
I figured out my method cuz the TX had no decent place to put a level. Once I saw how easy it was, I quit using a level completely.
The trick is to draw a line through the two groups you shot to test. Then put the gun in a rest and align the vertical crosshair with the plumb line. Carefully loosen the scope and rotate it so that the vertical crosshair now lines up with the line through your groups & retighten.
9 times out of ten you'll reshoot and your new groups will fall on the plumb line. You might have to repeat the procedure a couple times till you get the hang of it.
K
I've read all of this with great interest. It seems to me that it all assumes the scope and barrel are coplanar relative to gravity. Most scope mounts clamp from one side, introducing a potential eccentricity. What I've always done is figure out a way to verify the levelness of the action, then clamp it down and rotate the scope to align the vertical crosshair with a plumb bob string. Recently, I've used a vertical laser line from a PLS, which is self-orienting.
With regard to how it shoulders, I concur with the idea of an adjustable butpad. First of all, get everything lined up the way it should be, then figure out how to make it comfortable.
OR just figure out how to shoot it. I've been to several outings with my shooting buddies, where we frequently swap guns, and I've been amazed at what I see thru their scopes. What works for one guy might not work for the next guy. Ranging requires serious vertical consistency, but how you shoulder and hold the gun figures into that also.
There is SOME science, but no hard answers, and no substitute for trigger time and experience with any given scope-rifle combination.
Before getting carried away, do this, assuming you have a bubble level mounted on your gun. If you are right handed, shoulder the rifle, check the bubble for level and look through your scope. Bet your reticle looks a bit crooked in the counter clockwise direction. Now should the gun lefty and do the same. Bet it looks crooked in the clockwise direction. This has more to do with tilting our heads when laying our cheeks on the stock than anything. Level your gun, level your reticle (actually get the vertical cross hair, to use an antiquated term, perfectly vertical and never mind the horizontal cross hair), trust your bubble level when you aim and forget about how it feels. If the feel still bothers you, take the advice of the fella who recommended an adjustable butt pad that can be rotated. I have small bubble levels on all my dovetails. First I level my guns. Then, looking through the scopes at a carpenter's level hanging perfectly vertical on my fence, I rotate my scopes so the vertical cross hairs line up perfectly with the edge of the carpenter's level, tighten the screws and I am done. If the bubble says "level" I know my vertical cross hair is straight up and down and I am ready for hold over or hold under. I have yet to try any fancy tools to see if my scope is centered over my bore, but I have tried the mirror trick a time or two and could not discern any alignment issue.
Good luck friend.
R1lover I am glad that you got this post back on track because when people start talking about how to level a rifle and scope it was kind of not on the same plain as I was talking about meaning the feeling of the rifle and the way reticle looks like through the scope. I'm going to try what you suggested and report back. Thank you
Josh3rd, glad it helped. The most important thing I've learned from using bubble levels is......that I need to use bubble levels! Lots of shooters shoot very well without them, but without a bubble level I tend to cave and give in to the optical illusion that I am holding my gun crooked when looking through my scope and compensate for it, which results in me really holding my gun crooked. Checking a bubble for level before pressing the trigger assures me that things are "plumb" and guarantees consistent aim (very important) shot to shot. The longer the shot and/or the lower the velocity and loopier the trajectory, the more pronounced the effect of a canted rifle becomes.
Yes, the vertical retical alignment tool" is the best thing though I had made a reasonable substitute tool before buying the storebought one. Anyhow, first bring the gun level so the scope bell center is directly over the center of the barrel. Then align the crosshair with a plumbline or distant carpenter's level. Then mount a spirit level on the scope tube so the bubble is centered when the scope is directly over the barrel center and the crosshair is squared up.
I designed and built target rifles with deliberately canted actions that shoot perfectly true all the way out ... because what matters is the scope is over the boreline and the crosshair is squared up EVEN though the action and grip angle are near 40 degrees off in some guns I made.
I think if you tried an adjustable butt plate that you could rotate it would solve most of the cant problem you are experiencing when shouldering the rifle. I would do that before rotating the scope to adjust for the hold.
I like the adjustable butt pad approach to account for an 'error' that naturally occurs due to the anatomy of the human body.
Let's assume you've already done whatever was necessary to have the vertical part of your scope's reticle perfectly straight up and down and bisecting the rifle's barrel. Having an adjustable pad and adjusting it--just slightly should be enough--to the right angle will probably take care of it IME. The reason is that the angle of the intersection of your arm and your chest isn't perfectly straight up and down, so when you shoulder a rifle into that intersection, the rifle tends to tilt e a bit (as I think was mentioned in one of these other posts in the thread). Adjustable butt pads can be set to match the angle of that intersection and thus negate the error caused by the angle.
I found this out in a big way when I was fortunate enough to tune some R11's aka the HW 98. Having the tilt at the butt pad gave me repeated level sighting and easier-than-usual accuracy when I pulled the rifle into my shoulder, and I loved it. Using a bubble level that's mounted on a scope ring or the top of the receiver is fine for setting up and double checking from time to time, but I don't want to have to refer to it constantly when I'm shooting a lot of pellets.
I don't compete and I don't even do small game hunting anymore, at least for now. But, if I was shooting in circumstances where every shot counted, I'd probably be using adjustable butt pads on all my rifles. For the shooting I do right now, which I guess I'd call, "semi-serious plinking and target shooting', the fixed factory pads are good enough. But, I reserve the right to change my mind at any time should I start wanting to shoot with more precision.
I've sighted-in quite a few rifles and also tested them for accuracy, but I don't want to contradict Airguntunes in any way if he's done hundreds using his methods and gotten stellar success. I'm just saying that based on what I've seen and done here, the adjustable angle butt pad cures a lot of accuracy ills IME.
Speaking of experience, LD has set up and even designed quite a few match winning rifles, so I sure don't mean to contradict anything he's saying either (if I am). I'm just saying that a small butt pad adjustment gave me the good results I was looking for with a rifle whose scope had been properly set-up, without having to constantly refer to a bubble level that was mounted somewhere on the rifle.
P.S. And, I'm humble enough to say I realize I may be in a little over my head when it comes to this particular subject. I've never shot a filed target match in my life. I've tuned quite a few rifles for those who do shoot them, but they told me they were going to run through their favorite scope set-up routine once they got the rifle back home to make sure everything was 'just so', even if I sighted-in their rifle here to do my testing.
Pick a method you like and I'd align the bore to the center of the scope ...........
The coolest old school method to check canting error.
U need a large leveled backer board and keep the gun level at all times when shooting.
Take 3 shots on board and this will be your POA for the shots below.
20 MOA / clicks up take 3 shots.
20 MOA / clicks left take 3 shots.
20 MOA / clicks down take 3 shots.
If the connected groups are a perfect square, no canting error.
If it looks like a parallelogram, u have canting error.
In the direction that it leans is the canting error direction also.
Assuming no wind of course.
The Tall Target Test (TTT).
~ Greg
