Scope and rifle levels

[short range]

what is a good system to make sure my scope cross hairs are mounted correctly, and also that my rifle isn't canted when I'm shooting ? I have a Stolle Panda action, so the magnetic levels won't work. I have a Leupold VX111 36x scope.

 

[GerryM]

One way is to put the rifle in a padded vise by the barrel.
Level the rifle in the vise lenght wise and side way make sure it level in both directions. then install the bottom half of the rings next the scope and top half of the rings. Level up the scope on top of the elevation screw caps.
It should be good. check it both ways also.
One hint those leupold scopes have a slightly off center reticle
Not much but just a tad.
hope this helps

 

[boogershooter]

Short range , use that search block up top cause someone on here a while back posted a very good, informative read on the subject. I think it was preacher or gunamonth or dear catshooter,I miss him! ,but very good! I start with a plumb bob of sorts and level the hair to it then level bases. But read that article, its edjamacational ;D You'll like it.

 

[BoydAllen]

The tool that you have pictured is what I use. Getting the center of the scope directly over the center of the barrel is the only correct starting point from which to roll the scope till the vertical cross hair is parallel to a plumb reference. BUT, for long range work, where the turret is run to adjust for distance, a reticle that is slightly canted realtive to the travel of the intersection of the cross hairs can throw you off. Which is why it is a good Idea to do a shooting test for this application. I hasten to add that I don't do this sort of shooting, and for most applications at reasonable ranges, putting the vertical cross hair vertical works fine. As far as leveling the rest goes, with 3" wide bags and flat forends, it is common for the surface of the bag that the rifle rests on not to be parallel with the rest that it is a part of. At the range, I usually make sure that my target is stapled on reasonably vertical and then I simply adjust the rest so that my cross hair is parallel to the side of the target. When I remember it, I have a torpedo level in my range kit that I take to the target line and use it as a reference when stapling my target to the frame, after first placing the frame in its holder. this gives me pretty good horizontal an vertical references. I got the idea from a serious small bore (prone) shooter.

 

[camac]

Hi guys,
A couple of quick points I would like to make here.
1) I believe as long as there is a level on your scope and you put it in the same spot everytime then the bullets will have the same point of impact everytime (variation in accuracy ignored). regardless of whether scope level is level with crosshairs or stock. Once sighted in at that range, do the same process every time you go to take a shot and it will work. ie you have the same "cant" on every shot. Whether it is perfectly 0 or 5 degrees does not matter as long as it is constant. This idea is visble most in the canted leupold crosshairs. They are still accurate but just takes a little more "thought" in adjusting for range.
2) The reason for aligning it all is more for vertical scope adjustment at range like Boyd suggested. Adjustment is easier being in a linear plane so is handy nonetheless but not as critical as you might think. Hey but no bullet travels in a perfect vertical parabola anyway, especially with loads of spin and some drag.

A simple trick though is to place a spirit level in the ground some distance away but perpendicular to you so you can align the horizontal crosshair (or vertical if you prefer. Put another level under your stock (if you have a nice wide benchrest style. Now align your scope crosshairs with the level on the ground, tighten mounts and double check and finally afix your level on the scope - easy! as long as the three bubbles are ok then no worries (canted reticle Leupolds excluded). Check with your vertical adjustment at different ranges like Boyds suggestion. If you find you don't need to add much windage in calm conditions changing ranges then all is good.
CAM

 

[short range]

Thanks guys for the info, that's very helpful.

 

[BoydAllen]

How do you know that the bottom of the stock is perpendicular to a line that runs through the centers of the scope and barrel? There is no real need to have the bottom of the stock exactly level. I prefer to know that all of my scopes' cross hairs are correct when their centers are over the centers of their barrels...round bottom or flat. If something is going to be out of whack, I can live with the bottom of a flat stock being a smidge out of level. It is of no functional consequence.

 

[BoydAllen]

No argument there. it's just that I have standardized on one way, to keep it simple, and it does not seem to cause any problems.

 

[camac]

I am trying to get my head around cant and draw some pictures - I don't confess to being the smartest kid on the block so forgive me if I get it wrong.
I am thinking you are mostly right Boyd but in the pactical world the simple method seems to work for me - similar in principal to your using the level on the target though. By leveling crosshairs, scope level etc with spirit level on the ground is effectively the same as leveling crosshairs with a levelled target. or indeed the vertical with a plumb bob. It indeed does not guarantee that the vertical line of crosshair goes down through barrel centre at the time of mounting the scope but it does give you a repeatable horizontal/vertical level. Indeed the key to this isn't the fact that the stock is level (I will forgive a little error there - just nice if it is and most times a bit of adjusting bedding screws etc will fix) but that the crosshair is level with the horizontal spirit level (like your level target or the vertical plumb bob) at the time and that you set your scope level bubble to that.

BUT I do believe if the crosshairs are gravitationally vertical (or horizontal) depending on which way you look at it then you will just have to correct for windage to align the centre over the middle of your barrel. Please correct me if I am wrong. If the crosshairs are gravitationally vertical then the bullet path (drift and wind aside) should fall straight down the crosshair plane.

Try sketching it - a badly aligned stock with a barrel and scope mounted (e.g. 5 degrees out). Now sketch in the crosshairs level with the stock (and ground). The scope has to be badly canted in mounts but What actually happens is you have to wind the windage right over to above barrel to sight rifle in. Effectively even though scope itself is not directly above the barrel the centre of crosshairs have to be to sight it in..

Hopefully that makes sense - otherwise I will try and sketch some diagrams somewhere on line for you.

 

[short range]

Thanks again for the info, it's all very helpful. Steve

 

[Rust]

Being sort of simple-minded I leveled the rifle by way of a precision magnetic level on the lower half of the scope rings, and then used a plumb bob to check the vertical cross hair against. I also used a carpenters level with the pecision level to check the horizontal cross hair against out by the plumb bob. That last tells you if the crosshairs in the recticule are square, something that is not always true of Leupold.

If the crosshairs are not square, I prefer to have the vertical crosshair at true vertical. But all my competition scopes are Nightforce so it hasn't been an issue ;D

In the field I prefer the US Optics level that mounts on the rail to ensure the rifle is square every shot. Works pretty well.

 

[camac]

Once again everyone is getting to the same point but have devised different ways of getting there - very interesting and informative. If you want to avoid cant, a scope level should be employed (or other means of holding the rifle in same postion all the time such as level targets etc) that is the critical part - consistancy. And for some convenience it should be level with your crosshairs. Except on a "canted reticle" leupold and then probably the best suggestion here so far is GerryM's first one as you need to actually align with vertical adjustment. Hopefully this is square to the turret screw caps as he suggested.

An interesting point though for long distance. I plugged some figures in to JBM's calculation site. 1 degree of cant for my 6.5 x 284 shooting 142gr sierra's at 1000 yds is 0.7 inches of windage, drift is 7 inches both these are constant (if you have a level) and can be adjusted in sighters. Every knot of wind is also 7 inches and is variable. I have never shot 1000 yds in 0 knots. In fact I have never shot 1000 in under 5 knots. As I said earlier - not as critical as you might think., But also even more interestingly you could dramatically reduce the effect of drift (and hence give you a more true vertical adjustment)by canting your rifle -5 degrees!!!! Although technically drift is in a spiral not linear.(As I said before forgive me if I am wrong here - I didn't do the calculations - just plugged them in!!)

 

[camac]

Although - to add. I just calculated 274 inches (drop) x tan 1 (1 degree cant) = 4.78 inches. Can anyone explain the discrepancy between this and the JBM calc??

I am trying to get my head around it and believe JBM is correct and the reason why cant can almost be ignored in real conditions at range. I don't think the tan calc that everyone uses is correct. It is more complicated. Anyone want to dare to try and explain this in the thread?? This deserves a new thread - maybe we can lure in someone that really knows what is going on here.

 

[KTim]

Well, I have a simple system that works for me, and i think it could be the most accurate IMO.

mount your rifle (bi-pod, vise, rest , or by hand if that is how you will be shooting)Doubt anybody holds rifle perfectly perpendicular when they are shooting anyways.

hang a plumb bob , adjust your scope so the vertical cross hair matches. I cannot think of a simpler and truer way, It works for me and don't cost more than a string and a weight.

 

[canuck]

Just a little something to add. Once you think you have the scope/rifle level put a piece of tape running perpedicular( use a level) at 100 yards. Then shoot at the bottom of the tape with the gun perfectly level.Now dial in 25 moa or more and shoot again. If it cuts the tap you got it.