Scope cant from a rotational standpoint
 

Will unlevel crosshairs lead to long-range inconcistencies in accuracy? What about precision?

I believe that in theory it should have no affect on precision/accuracy.

The issue is when you're dialing your scope in each click will not only move the hairs up/down or left/right but both at the same time.

Ie if you're cross hairs aren't level and you are shooting an 1" low and try to move it up, you may also be moving left or right depending on which direction your cross hairs are tilted.

Tom

Thanks Tom,
My concern was that with just 'eyeballing' the level of my scopes, I might experience a drift or some other variable at extended ranges (over 500yds). I have only shot to 500yds (maybe about 600 with a few shots on one occasion) so far and haven't experienced problems.

At those distances I could see that maybe it could affect you. It may be possible that the cross hair being unlevel may cause you to unintentionally square the rifle to the cross hairs instead of holding the rifle itself level.

Something tells me that your cross hairs are pretty level. You're just wondering if you should measure them to be sure?

You may want to get the opinion of one of the long range shooters on the forum like RR or others around here.

Tom

Exactly, I'm wondering if a scope leveling tool would be necessary to minimize variables or if reasonably-level will do the trick as it is.

Where can you get a scope leveling tool? I've always eye balled it too and sometimes have problems. Like when hunting with my muzzle loader the other day I noticed the crosshairs are just slightly off center. Not much but if I really tried to hold the gun level I could tell they weren't perfect. I didn't notice this when mounting it or sighting it in and it shoots well at 100 yards so I hate to take it off to adjust it and have to re sight it in again when it's barely and I mean barely off. l the width of that letter there is probably about how far off center it is. I just am a perfectionist and want stuff like this perfect.

HTM, at cabelas there's a tool used with a laser bore-sighter and level than projects a horizontal line out the bbl. You adjust the scope accordingly. Or there are levels you can use. A full set of professional tools for ring lapping, leveling, and ring alignment etc. will run you about $100.

Or you can spend about $2 and go buy a couple of cheapo 2" levels from your local Harbor Freight or an auto parts store, use one on the action to check the level on the supported action and the other on the top turret. There you go a level crosshair.

Here's a good, cheap investment for scope users. It works great!!!

http://www.midwayusa.com/viewproduct...tnumber=529349

RR your diagram makes some sense, but it seems like the resulting bullet impact of canting the scope to the right would be lower (because your crosshair is closer to level with the bore) and to the right (because the scope is to the right, and the scope should be set so the bullet matches its point of aim at 2 points during its flight). Maybe I'm looking at it wrong (we're assuming the rifle was sighted without cant before this scenario, yes?), but I do know that a projectile cannot 'rise' at any point during its flight, its drop can only be compensated for by the angle of crosshair in respect to a straight line down the bore.

Do you think it is necessary to use a scope leveler to minimize cant errors in regular shooting, or do you think eyeballing is good enough when installing the scope?

I wanted to share this method I just read about for aligning your vertical crosshairs. Hang a weight off of a rope about a hundred yards away. It will be straight up and down, so with a level on the rifle you can rotate your scope to match. Bingo. Think this will be how I do it.

Thanks for the tip RR, I'll be giving it a shot. I know I'm not level because I just eyeballed my mounting, but as I'm going to try and get into more long range stuff at 500 and beyond, I now know I need to sweat the small stuff when it comes asking the most out of a rifle. I saw a pic of a gun, and the scope had levels mounted on it for shooting. Do you keep a level mounted on your gun while using it?

On my varmint rigs where I realistically have the possibility of 300 yd + shot I have levels mounted on the scope tubes. For my hunting rifles my self imposed limit is around 300 yds so I don't feel it necessary.

RR,

Does the B-Square level need an actual slot or can it attach without one as long as you have a weaver base with some room behind the ring?

Thanks

Tom

I'll be getting one of those for sure!

Tom

yes canting either way could throw off your shot due to the bore's being installed with a slight up angle to give your gun a firing arc. this is only an issue at LONG ranges though.

Also some times you can throw your self off by holding the gun off level also, again it really only applies to 1k meter shooters though. Even then its only a matter of inches.

Just FYI IMO