Scope Cant

[BillyGoatMachine]

The bubble levels are for people that cant figure out what level looks like.

Try shooting on angled, uneven ground off a bipod while prone. Maybe you can, but I can't tell what's level sometimes while contorted on the ground. I'm partial to Flatline Ops levels as all I have to do is open my non dominant eye and the level is visible without losing cheek to stock contact.

[CK_32]

Try shooting on angled, uneven ground off a bipod while prone. Maybe you can, but I can't tell what's level sometimes while contorted on the ground. I'm partial to Flatline Ops levels as all I have to do is open my non dominant eye and the level is visible without losing cheek to stock contact.

Throw a bubble level on their rifle. Watch how quick their "level" rifle. Is actually not level.

I've had people laugh and say the same thing. Then tell them ok mount and level my rifles then and see how easy it is. Don't look at the bubble.

They get set up, and the bubble is all the way off to one side or the other. Lol

My one friend did it 6 times before he would say ok it's useful.

[calshipbuilder]

Makes me wonder what the pictures in there house look like all angled every which way....

Another good use for my bubble levels, I have a 4' version for that

[LynnJr]

Throw a bubble level on their rifle. Watch how quick their "level" rifle. Is actually not level.

I've had people laugh and say the same thing. Then tell them ok mount and level my rifles then and see how easy it is. Don't look at the bubble.

They get set up, and the bubble is all the way off to one side or the other. Lol

My one friend did it 6 times before he would say ok it's useful.

CK32
What happens if my gun isn't perfectly straight up and down?

[postal]

Try shooting on angled, uneven ground off a bipod while prone. Maybe you can, but I can't tell what's level sometimes while contorted on the ground. I'm partial to Flatline Ops levels as all I have to do is open my non dominant eye and the level is visible without losing cheek to stock contact.

I shoot precision rifle for fun- with a harris swivel. No pod lock. I torque the nut enough to hold the rifle in position on demand, but I can force the rifle to cant as I please.

Yes I shoot off uneven ground. Baracades, ladders, barrels, out of trashcans, tripods, rooftops, through chain link fences, and positional (which doesnt require a bipod)

Maybe you shoulda had a V8...

And.. why are you "contorted" while prone? Uneven ground doesnt matter unless half your body is uphill or downhill like shooting over a berm. Otherwise, I think you're doing it wrong.

Unless you have an ear infection that throws off your balance, you should be able to look at something and determine fairly closely that it's level or not..... Or you need a V8...

Edit--- my google fu sucks.... yrs ago there were v8 juice commercials with people walking around angled about 30 deg off cant.... " I shoulda had a V8 (to straighten up) was the commercial. Though I cant find it on bube tube

[calshipbuilder]

CK32
What happens if my gun isn't perfectly straight up and down?

For a competent explanation of what happens, read:

Accuracy and Precision For Long Range Shooting by Bryan Litz, Chapter 8: Leveling Your Sights.

He explains how a 3 degree cant in your scope can cause you to shift POI by ~25" at 1000 yards (308 win). At the Pala matches I shoot 1-2 moa steel targets at just under 900 yards, so yeah, its an issue for me.

Also, note that you can have the scope canted in relation to your rifle (mounted a bit off), and that's OK as long as the scope is level in relation "to the fall of gravity".

http://www.scout.com/military/snipers-hide/story/1540059-canted-rifle-level-scope

Hopefully someday I can get comfortable with the way my reticle needs to be, but until then, the level is my friend.

[50BMGBOB]

One thing to also watch for is during a match with my 50 the torque from firing will start to sink one leg of the bipod into the ground as the match progresses. Some can't in the bipod makes it easy to correct. A bipod without can't and you may have to re level or position between strings.

[killshot44]

And that's why my Dasher wears one of these.



Sticks out just enough on the left side for my non-target eye to confirm that it is level, step #1 in my pre-shot routine.

[LynnJr]

Bob
Your giving away all my benchrest secrets. In benchrest your rifle rides on rails and it doesn't/can't be canted between shots like a bipod rifle that swivels can.

In the example above given by 50BMGBob with one leg getting driven into the ground a lot of shooters would twist the stock to roll it back onto the target introducing can't and opening up there groups.

If your rifle isn't changing its footprint between shots how is the cant introduced while still remaining on your point of aim?

In Skkeeter example the shooting position were we shoot is on a side hill facing down with a convex to your spine or nothing flat. The spikes on an Atlas bipodare long but don't have pads on them which allows for cant.

The F-Class shooters use points but they also have larger than normal feet so once the point is pounded in they remain in the same position.

[BillyGoatMachine]

And.. why are you "contorted" while prone? Uneven ground doesnt matter unless half your body is uphill or downhill like shooting over a berm. Otherwise, I think you're doing it wrong.

Unless you have an ear infection that throws off your balance, you should be able to look at something and determine fairly closely that it's level or not..... Or you need a V8...

Try hunting sometime. Then tell me how I'm doing it wrong.............

All I was saying was that not all of us are graced with your exceptional physical skills of knowing when things are level or not, because I'm def not. Cool, you obviously shoot matches all the time, off every conceivable barricade, fence, whatever. I'm actually jealous because I live in the sticks and Lynn's ELR comps are the closest matches to where I live, and also the only 2 I've ever competed in. Maybe I should get some antibiotics and veggie juices, so I can improve my skills.

[killshot44]

Bob
Your giving away all my benchrest secrets. In benchrest your rifle rides on rails and it doesn't/can't be canted between shots like a bipod rifle that swivels can.

In the example above given by 50BMGBob with one leg getting driven into the ground a lot of shooters would twist the stock to roll it back onto the target introducing can't and opening up there groups.

No doubt about that, I've shot critters while set up downhill using an Atlas with one leg waaay longer than the other and having a bubble helped keep things level shot-to-shot. Didn't help my back any, though.
Surprisingly, I didn't need a cosine indicator when shooting downhill.

If your rifle isn't changing its footprint between shots how is the cant introduced while still remaining on your point of aim?

Normally it doesn't. Just an aid during Prep Time.

The F-Class shooters use points but they also have larger than normal feet so once the point is pounded in they remain in the same position.

True, I use Bob Pastor's feet which work well with the Farley. Works great for gravel, though for soft surfaces it'd be nice to have a 1"-2" spike to better dig in.

Bottom line, the bubble level is a cheap aid that helps if it's used properly. More than we can say about a lot of the crap we concern ourselves with!

[JMP]

I just tried to go shopping for a bubble lever, and what's telling is that folks keep insisting that they are good for "long range" because the big error margin keeps multiplying. However, I cannot find any products to fit a proper long range scope with a 36mm tube needed for elevation, just stuff to dangle from the top of the mount. Then, it seems like the bubble levers are most cheap Chinese made contraptions based on all the negative feedback on the products.

The fact is that long range shooters are consistent and queue off of their bullet impacts.

[penguinofsleep]

Lynn - I'm not that knowledgeable on long range shooting as you may know from advising me a few times, but the picture killshot44 posted nails it just based on geometry/trigonometry.

If I understand the question and you are asking what I think you are asking: In simple terms, scope cant causes every apparent change in the Y (up/down) direction that you see in the scope is actually a change in both Y and X (left/right) when the scope is canted. This applies for any intended change in the X direction as well. Additionally, any expected change in X or Y will not be the expected amount either b/c some of the movement now goes the other way (hence shooting left and low in the posted picture)

However, I also imagine that as long as you are consistent in your cant or other minor errors and you are already correcting for them consistently too, it isn't a huge problem. The above makes calculations, adjustments, and anything else that requires changes harder but if you "correct" everything via adjustments during trail/error (ex building dope card) and eventually get the desired results anyways, then I don't see a big problem (outside of competition).

[penguinofsleep]

On a different note, for those who use a level and don't have one in the stock as Randall has suggested, is it a problem if the bubble is "upside down" so to say?
ie instead of having the bubble on top of the scope, have the bubble on the bottom of the scope near the base. That way if you open the other eye, you can still see the bubble level with maybe a minimal shift of the face at most, which if done correctly, probably wouldn't result in enough change for the bubble level to pick up. (idk if you are still "supposed" to shoot with both eyes open with a magnified optic anyways, but past 4x or 5x, I can't do it.)

[killshot44]

JMP, the B-Square one shown clips to one slot in the scope base. Works with any size tube.

Penguin, a bubble level should work that way. They KEY is ensuring that the stock, barrel and scope are all vertically aligned and that the level is in synch with them.
Theoretically one could make a canted reticle work for them, dealing with the trajectory by windage and elevation corrections, as long as it's repeatable.