Where does Rifle cant begin to matter?

Obviously some anticant/scope levels are not equal. The plastic cheapies usually strip out, like the 3-D printed. The saying "you get what you pay for" applies here. I researched cant several years ago, tested the information and now have a level on all my rifles. I don't trust my eyes to give me exact level, too old.
 
I don't look at my level until I'm shooting at 300 yds or more. I use my reticle for hold over so a level is a must and in the mountains or when shooting on unlevel ground it's easy to be 10 degrees or more off level even though it feels and looks right. Even a cheap level works and is worth not wounding game.
 
If your a flatlander, those references may work well, but if you then go into mountainous terrain, a solid vertical or horizontal reference may be difficult to obtain (perhaps trees?). Agree with 338 dude, 10-15 degrees is extreme. I would assume most people could eyeball 3-5 fairly consistently. I should think some relatively basic geometry should be able to get you close to the error at that range. Too bad I suck at basic geometry.
Mountainous terrain will really mess you up, out in the west we even put a level on a bow! When you "think" you have the rifle/bow level then "Look" at the level and you then realize how far canted you can be. You might not miss but a bad hit and an animal that cannot be recovered is not a fun time.
 
Alright guys, here's a little test:

Most of you will be looking at this through a smart phone. Hold your phone at arm's length and look at the image below. Can you recognize which line is plumb and which line is not? Now rotate your phone counter clockwise until the canted line looks plumb and look at the top of your phone. Can you tell that the top of your phone is not horizontal?

I'm not saying never use a level. But a simple look at the top of your turret is getting you very close. Not to mention the levels that are built into our ears/eyes/brain. You shouldn't need a level at 300 or 600 yards regardless of environment. I've shot to 1,400 yards without a level and was just fine.

1604000220349.png


Here's another tip: when shooting paper, first make a mark on the target backer with a 4-ft construction level (after you check the level to make sure it is correct). This way, everytime you shoot paper you are forcing yourself to be behind a rifle that is not canted. Pretty soon you will be able to know what right feels right, and you won't need a device to tell you what you should already know.
 
The chart shows -0.43-inches of vertical error at 300-yards with a 10-degree cant using a 308 (168 SMK with MV of 2700 fps, 2-inch sight height, & zero'd at 100 yards). The horizontal error is 4.95-inches.
View attachment 222169

Again, you'd have to have something serious going on to be 10-degrees off, see below for reference
View attachment 222170

@trhall , the error is non-linear. The error is dependent on time-of-flight.
True, but a linear calc will be well within minute of deer. It's kind of like the calcs I do in the field for MOA. Using 1 minute = 1" at 100 yards linearly instead of actually crunching 1.039" gives me an adjustment that is more than close enough.

Looks like I was way off. Thanks for ponting out my error.
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I realized the effects of canting when I started match shooting at distances of 200 to 1200 yards.
at the 200 yard distance you could barely tell any difference unless you were canting very badly.
You may not realize you are canting at all unless you have a reference, and the level can be that reference that is always there.

But when stretching it out, it became a problem and the farther the distance, the worse the error in impact. We used iron sites, so the problem was position, and the canting was related to how well you held the rifle vertical. For the long distance shooting 600 and over, we set up a test target at each distance (200, 300, 500, 600, and 1000 yards and shot the same POA on each target and then adjusted the scope to get the POI in the same spot (Center of each target).

The nice thing about having a level on your rifle now, Is that while practicing it can be used for a reference to check your position and when hunting if making a long shot you can refer to the level to verify your hold and position for the best shot.

Some people have the natural ability to see a level condition. others don't have that ability so it is recommended for them even to develop the skill/ability to level everything. As the the importance of not canting, it can only help no matter how far the shot. For those that like to shoot bug holes, The level can even make a difference at 100 and 200 yards. If use, it will be more consistent in positioning the rifle the same every time. It may only be a few thousandths, but thousandths matter in the accuracy game.

The level is a good tool to use and train with, especially when in mountainous terrain where there are few level or vertical surfaces to assist you.

J E CUSTOM
 
Alright guys, here's a little test:

Most of you will be looking at this through a smart phone. Hold your phone at arm's length and look at the image below. Can you recognize which line is plumb and which line is not? Now rotate your phone counter clockwise until the canted line looks plumb and look at the top of your phone. Can you tell that the top of your phone is not horizontal?

I'm not saying never use a level. But a simple look at the top of your turret is getting you very close. Not to mention the levels that are built into our ears/eyes/brain. You shouldn't need a level at 300 or 600 yards regardless of environment. I've shot to 1,400 yards without a level and was just fine.

View attachment 222217

Here's another tip: when shooting paper, first make a mark on the target backer with a 4-ft construction level (after you check the level to make sure it is correct). This way, everytime you shoot paper you are forcing yourself to be behind a rifle that is not canted. Pretty soon you will be able to know what right feels right, and you won't need a device to tell you what you should already know.
I respectfully disagree, good Sir :) I have shot with many friends that when I mounted their scope level, they thought it was off even at the range off a bench. I would stand behind and say "watch your level" every shot because they would be canted. I worked as a iron worker, carpenter, etc to get me thru college and can tell you a level is a must no matter how much practice you have putting up walls, block, trim, etc. Levels make us consistent so we aren't questioning our wind call, spin drift, scope mounting error, etc.
 
I respectfully disagree, good Sir :) I have shot with many friends that when I mounted their scope level, they thought it was off even at the range off a bench. I would stand behind and say "watch your level" every shot because they would be canted. I worked as a iron worker, carpenter, etc to get me thru college and can tell you a level is a must no matter how much practice you have putting up walls, block, trim, etc. Levels make us consistent so we aren't questioning our wind call, spin drift, scope mounting error, etc.
Yeah, levels have a time and a place. The context of this thread is "do I need a level out to 600 yards".

If you need to look at a level before every single trigger press (especially if you're only shooting to 600 yards), you aren't progressing. I can feel if my bolt picks up a round vs running on an empty mag. I don't need to perform a press check each time I run the bolt. I can also feel if the rifle is canted.

As far as your buddies go, lots (most) people have a natural cant. If they don't have adjustable butt pads, and if they have conventional hunting stocks, it's not always best to have the scope plumb to rifle. Level the scope to gravity so that "right" is natural - refer to the graphic in my first post.

And, we can always just agree to disagree.
 
I hunt out west in the mountains so the feel it level doesn't work for me on a slope shooting down hill and partially perpendicular to the slope I'm on. Too many angles for my brain and a quick open of my non dominant eye confirms if my level says I'm good or not. And I wish I had the skill and practice to say "only 600 yds". That's a long poke in my book.
 
If your Scope is canted a few degrees either left or right it will really effect your point of impact especially when you use wind holds or dial for elevation and it will be a linear thing. It's due to point of aim every one degree is 60 moa at what ever yardage we tend to notice it at longer ranges when its easily noticed that was the reason for the misplaced shot.

For example if I use a right wind hold (a 3 o clock wind) of 1 moa on a scope that is canted vertically left ie the top cross hair is tilted left. I will miss high right due to the displacement of the reticle low left before you made the hold.

If you have the same situation and had to use a 2 moa wind hold the point of impact will move both left and up due to the cant and yes it will be linear because of the angle.

ITS BEST TO USE A LEVEL AND HAVE THE SCOPE PLUMB TO THE LEVEL.

The amount you may be bothered by this is up to the shooter and how picky the shooter is. Bench rest and Fclass probably more than a plinker or short range hunter.

Here is the technical info for you question. I know its a lot but it's cool to me.

My best method is to use a 3/4" rope and a cinder block to make a plumb line were I place my rifle on bags and a comfortable hold for my shoulder. Then pumb both my level and my reticle.
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I have been watching YouTube videos on long range shooting. Primarily Barbour Creek shooting school. They did an episode where they illustrated how much a 10-15 degree cant can affect impact at 1,000 yards. What I am wondering is how much will it affect 500 yards, 400 etc? Is this a linear thing where 500 would be off half as much as 1,000? Main reason for asking is if I do not shoot beyond 600 yards, is a scope level absolutely necessary?
I shoot Bench Rest matches from 300-1,000 yards, and having a anti-cant device is required to be competitive. What you want to do is to be conditioned to mount your rifle in a consistent manner, without twisting left or right. Most people me included will cant when shooting free hand, so at short distance it may not be an issue. However at long distance it will throw your shot off the mark. If you are aware of what you are doing, you can correct your hold to move your impact back center.
 
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