There are a lot of schools of thought when it comes to leveling a scope to the rifle. 90% of them are wrong. Technically you are not leveling the scope to the rifle, you are leveling the scope to gravity. The bullet only cares about gravity and the rifle is just a delivery vehicle for the bullet.
I have written about having a scope that is set up level to the rifle vs having a scope set up level to gravity. The difference in the second case is, the rifle is slightly canted to fit my natural hold. If you want to understand your natural hold better, consider the rifle mounted level people use to shoot with. If you add a bubble level to your rifle and each time you address it, especially in the prone, the bubble is off and you have to adjust the hold to straight out the level. This is what we call a clue. A level is a not a Shooting Aid but a Training Tool. It's telling you, your natural hold is not straight and the rifle should be adjusting to that natural inclination you have to cant the rifle. This is the reason super duper Air Rifle and .22 Olympic Rifles are designed to by hyper adjustable. The Olympic Shooters understand comfort, they understand their hold, and they understand that under conditions where concentration is elsewhere , like downrange our body will naturally cant the rifle on us.
Here is the text of my Canted Rifle, Level Scope Article posted some time ago. But come back because I have some additional details to follow up with. Like the numbers that show a canted rifle with a scope leveled to gravity is better than a scope leveled to the rifle.
What are the effects of canting my rifle and leveling my scope to gravity at 1000 yards ? Here I shot several groups with a level rifle and level scope vs a Canted Rifle and Level Scope. The results might surprise you. Canted Rifle Level Scope
Before I start, I am not here to sell you a new product, nor am I here to offer you specialized training, I am just looking to provide some insight based on my real world experience which just happens to mirror some others.
If you read the instructions for David Tubbís DTR reticle you will see the first line says to address the rifle with your natural hold. The word ďnaturalĒ is a key piece of information here, as most people advocate an unnatural hold. They tell you to level the rifle, then to level the scope to the level rifle. In fact you can buy all sorts of things to help you level your rifle. Whether you use the rail, the bolt raceway, the barrel, none of it actually fits our body correctly. We are not built straight.
How many of you use a level on your scope or rail and think, ďitís a good thing I have this level because without it I would be canting my rifleĒ. I bet a lot of you. If every time you address your rifle and during your preparation for the shot you have to adjust to straighten your level you are missing out on a big clue. You body doesnít want the rifle to be level, itís telling you to fix it. What do you think will happen under stress ? What is the default position if you always have to consciously adjust it ?
There are a lot of discussions in the forum and on the internet in general where people advocate a level rifle to level scope. And honestly there is nothing wrong with that, but if you are a field shooter, it goes against our natural hold. The fact is, our shoulder pockets are not level, and when we address the rifle our mind will want to fix this by moving the rifle to fit us better. So we cant. Donít get me wrong, I have seen every diagram, read every justification, and will tell you are they talking in extremes which donít exist in reality. A little goes a long way to satisfying our brain. That $6 level you are using which is placed in a $100 wrapper is only accurate to within .8 of a degree. We are talking about working in and around this value.
For years I have canted my rifle every so slightly and then just leveled the scope to gravity. I can then, ďFeelĒ when it is not right in shoulder pocket. I am addressing the rifle the same every time and that tells me, everything is right with the world. Understand I view the level as a training aid, so for me I am well past that part of the course. I can successfully shoot UKD Targets, I am not overly struggling to make my software line up and I find I hit more targets than I miss.
I went out this week to see what would happen if I used two scopes set up different on one rifle. The first scope would be leveled to a level rifle using a Plumb Line, the second scope would be adjusted to my Canted Hold. When I say canted hold, I am saying my cant is probably under 1 degree. To repeat myself, I am still leveling the scope to the fall of gravity. This is key, the bullet is only concerned with gravity so we have to match that action. The rotation of my rifle and my scope does not move the barrel out from under the scope, itís within the tolerance of your bubble level as well as the manufacturers tolerance of their reticles. Scope companies will tell you 2 degrees or less is within spec, so the idea that you can guarantee better just because the reticle appears true is bit optimistic. Itís a mechanical device built by humans, small variations are bound to happen and often go unnoticed.
What makes me chuckle is when people talk about 5 degrees of cant or more. 5 Degrees is hugeÖ A very good shooter from Norway, Thomas Haugland has done some excellent videos on the subject. In them he demonstrates the accuracy of a bubble level vs the accuracy of the human brain. By using an electronic level accurate to a decimal place, he has shown the human brain is consistent to within .2 degrees. So you have a .8 level and .2 Mind, which one should you trust more ? Our Vestibular Sense is amazingly accurate which is shown in his videos.
He debunks the idea you need a level to be successful and I happen to agree. Remember we are talking small amounts, and not whole degrees, nobody is advocating your cant it 5 degrees or more, although I will add you can get a Tubb2000 rifle with a 0, 5, or 10 degree offset for mounting the scope.
Talking to a friend in the military who works on the precision rifle side of things, he also sets his rifle up with a slight cant. Through his efforts they have found that there is no noticeable Point of Impact shift by doing this. They have also found if you cant a level rifle you get about 3/16th of an inch shift per 2.5 degrees of cant. Then multiply that by each 100 yards you go out. So that is .1875Ē X 10 if you had as much as 2.5 degrees. 1.875Ē at 1000 yards. Remember, your bubble level from edge to edge is .8, so how far would you need to bury it in order to get to 2.5 degrees ? Most people would notice that and not press the trigger. Meanwhile others hit with no problems while that bubble is off center.
Explaining the Shots
For those keeping score, here were the conditions, 65 degrees out, 25.05bp, (6600 DA) and winds anywhere from 5MPH to 8 MPH. You can hear the wind changing in the video. I did chronograph the rifle and had a Muzzle Velocity of 2710, but 2650 seemed to true the computer up to just about right. I was using a Spartan 6.5 Creedmoor and the shots were all at 1000 yards.
We used between 8.5 Mils to 8.7 Mils to demonstrate, the center hits were at 8.6 Mils proper. The .5, .7 mils I spoke of in the video is the fine tune adjustment, not the total dope.
It does appear in going back I was off on my initial read of my turret, that I used 8.5 and 8.7 instead of 8.6 Mils. The two S&B 3-20x scopes have the MTC type turrets and hitting that .6 is pretty tough coming off the heavy detent. Itís a bit of pain if you are not paying attention. I went back and shot it several more times to confirm, so there was not question, operator error on my part. The last set of shots were repeated on target with a Level Rifle and Level Scope and confirmed the numbers 2 out of 3x. The last two shots were not marked but are clear on the target.
The biggest take away from the results was, that the wind was dead on regardless. Both groups matched my wind, if the cant mattered this would not happen. The computer called for .9 mils of wind, the most I used was .8 which took the group closer to center. The best part about using a Spartan rifle, I was able to use the entire target and by adjusting the wind holds slightly could place the shots on the four corners. Accuracy matters here. Try it,
I am not saying you need to go out and cant your rifle, only that canting a rifle and then leveling the scope is not as big a deal as canting a level rifle with a level scope. It is far more likely that you will subconsciously cant the rifle if you level it first, rather than set it up to your natural hold. Canting a level rifle is far more detrimental to accuracy.
Another remedy, using an adjustable buttplate. If you look at Olympic Air Rifle Shooters they have highly adjustable rifles. If you can adjust your rifle to fit by using a chassis or 3 way buttplate you solve the problems associated to an unnatural hold. I use Accuracy International Rifles for a reason, I can turn the butt plate to fit me. Then having a level rifle to level scope is a no brainer. Put the scope in a Badger Dead Level and then it goes right on the rifle. Your Dope is your DopeÖ
Remember your dope is just that, your dope. If you take your rifle out, check the drops at distance and record that information so there is no need to enhance it. Your dope is already your dope as you just proved this by hitting the target. Why people want to add things to their dope is beyond me, but they do it all the time. I went out, shot the rifle at distance and then molded the computer to fit my data. I did not try to make my data fit the computer. That is ass backwards. Once you have recorded your drop, be sure to record the conditions, set that as your zero conditions and then when you move from place to place to shoot the computer will be able to adapt to the changes. Simple. Use the Level as a Training Tool
Donít use the level as a crutch. Use it as a training tool to help you set up the rifle to you and your natural hold. Once you get the feel down youíll have no need to rely on the level to hold the rifle correctly. You know when your car seat has been moved, because you get used to it. Well you need that same presence of mind when it comes to your rifle. Donít worry about the horizon, quarter the target and focus on the crosshairs, not the skyline. I have never been able to comprehend people who want to reference the ground through the scope. The target can be at a 45 degree angle, I know what straight is in terms of the reticle. The level is giving you valuable information if each time you reference it the bubble is off. Do not ignore that information by repeating the same mistake over and over again. What is the definition of Insane ó> something about doing the same thing over and over again expecting a different result. Reset and adjust the rifle to your hold and the level will show true. That is why you want to use scope tube mounted levels so you can rotate them for your hold. Rail based levels will not help you with this.
I address the rifle with my eyes closed first, I want to feel it . Then I mount the scope and bring it to me. If that means the rifle is slightly crooked to get the best feel, so be it. I just drop a plumb line and level the scope to that holding the rifle naturally in my shoulder pocket. No tools, no tricks, no gimmicks. If you set up a scope tube level you can level that to the reticle and then just rotate it.
Try it, take a month and see how it feels and see if changes anything. All you have to lose is a little time, but thing of the experience youíll gain in doing so.
Okay, so I have proved that at 1000 yards the rifle is every bit as accurate even though I have canted it, and the dope remains consistent. Why is this... super easy, because the examples are:
1. Extreme - for effect they always cant the rifle beyond what a normal person would do
2. We actually cant very little
3. Scope companies have a +/- tolerance that is actually pretty close to the error we would normally introduce when shooting.
Devil's in the Details
Here is the math to demonstrate my point even better than tallking about it
Okay, I hope this helps... Set the rifle up to you the shooter. If your rifle has an adjustable butt plate to induce the natural cant, you can level the scope to the rifle using the flat of the rail against the flat on the bottom of the scope. If you rifle does not have this adjustment consider rotating the scope in the rifle ever so slightly so the reticle is aligned with the fall of gravity. (Plumb Line) and the rifle sits natural in your shoulder pocket. We are not built straight, are shoulder pockets are not perfectly vertical. By introducing that small adjustment you will be less likely to cant the rifle naturally.
Get beyond the rifle with the scope ever so slightly loose, close your eyes and go through several deep breathing cycles and get super comfy behind the rifle. Open your eyes and then rotate the scope to line it up to gravity using a level or plumb line. Now you are ready too shoot.