Which scope level?

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Dogleg

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I'm looking for recomendations for a 30mm, scope mounted or otherwise adjustable rifle level. What I don't want is a fixed one mounting to the rail, there's too many things that can go wrong that I've already seen.
What are the favorites?
 
What can go wrong?

The USO rail mount that swings the level to the side when not in use seams to be the cats a$$. place it so that the non-dominate eye can see it. Set up for the shot, open non-dominate eye to confirm, drop the hammer. Then when packing the rifle, fold it out of the way so it is not smashed.
 
carbonrod said:
What can go wrong?

The USO rail mount that swings the level to the side when not in use seams to be the cats a$$. place it so that the non-dominate eye can see it. Set up for the shot, open non-dominate eye to confirm, drop the hammer. Then when packing the rifle, fold it out of the way so it is not smashed.
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What can go wrong is that the US Optics level is not always level. Check this out:
http://www.snipershide.com/forum/ub...ain=58810&Words=bubble&Search=true#Post627750

DSCN1856.jpg


Read the article linked above the pic. It's not a one time thing, and it's not from incorrect mounting or anything else. The level is just wrong.

I suspect a lot of people's levels are like that, and they've just always taken it on blind faith that it's correct.
Now, that all being said, USO is supposed to have great support, so it shouldn't be a problem to exchange yours for a new one if it's defective.
 
I have those Starrett levels. They are very sensitive and can see a couple of thou over 3". You will note in the picture that they are adjustable and they do need this occasionally. The bubble in the rifle level will be no where as sensitive and if it was it would be unusable. The plastic level in the pic is probably junk as well. You should consider rifle levels for consistency as opposed to absolute level. Simple and cheap way is to take a vial out of your plastic level and glue it to the scope rail. Level the rifle to which ever level you use and then level the scope. It doesn't matter if the rifle is upside down as long as the level and the scope agree.
 
Ian, if you read the link they also used a starrett level, and one person did also glue the bubble to his rail.

Here's the pic with the starrett (top end) level, note that he says he corrected his USO level for this pic by putting a piece of tape on one side.
image1.jpg
 
Carbonrod,
What can go wrong? Here's a story and then you can tell me what you think.
4 of us got on a scope leveling mission a little while ago with heavy rifles. Three had Mark 4s and one had a Nightforce on 4 different Remington custom builds which were 3 Edges and my .300 Win Mag not that matters. The idea was to establish once and for all that the scopes were on straight or at least that the elevation turret tracked straight up and down with about 30 MOA of cranking while in a postion that the gun mounted level claimed to be level.
What brought all this on was one of the guys swore his rifle was level when the US0 rail mount showed a quarter bubble off level, and a long running debate on how much difference it made.
We used a wheeler engineering tool to ride the action rails and a selection of levels to establish a level position for the rifle, a straight line for a crosshair reference and a critical 4 man commity to eyeball the snot out of anything and everything. We also leveled off the turrets of the Mark 4s for science before we ever got there. That's a whole other debate, but while you're playing you may as well do everything you can.:)
The long and short of it is that when we all agreed that the rifle was level, the vertical cross hair lined up perfectly with the vertical reference we used when the level on the turret said it should.Maybe we were just lucky but those seem to be be on straight at least on these 3 examples. From there it went downhill. The guy who thought his bubble was off by a quarter was right. Another guy had what he believed to be a square mounted scope, which was true, but the rail was so far out of whack that you could see it. If you leveled from the rail it looked like the rifle was going to fall off the rest. His bubble was off the chart. I blame the base mounting screws being in the wrong position, and have yet another Remington rifle with the exact same issue.(It came out of the Custom shop like that, but I digress)The 3rd person believed that he had no issues with his rifle, crosshair alignment or scope mounted level and we believe that he was right all along. Myself, hell I don't even own a level so thought I was just along for the ride, but got roped into this as well. Swapping the 2 identical levels gave different results on 2 different rifles. Since those two rifles had the same TPS rail as me, we stuck one of the USO levels on mine while we were at it. This got interesting because when we went to mount one on my rail it was so loose it rattled when fully tightened. Great.:(
A short list of what can and did go wrong would be:
1) the level can be hooped.
2) The rail can be hooped.
3) The mounting holes on the action can be drilled out of whack. This one happens a lot more than you might think.
4) If any of the above conditions occur, there is FA you can do about it with a non adjustable rail level.

This is why I want a scope mounted level, even though I like the look of the rail job better too. At least I'll be able to work with it a bit. An adjustable rail level might work, if such a thing exists.
 
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Something to consider in all of this, using the top of a turret will NEVER be truly level.
Think about it, the turret is in the simplest of terms a fine threaded screw, threaded things will never be truly straight by nature of the way threads work. Close probably, but 100% true, never.
As Ian mentioned, as long as the bubble is always in the same place at trigger release, that is the more important issue. The USO levels often require shimming to get them to agree with a machinists level.
I prefer to level off of the ring 1/2, to get my rail mounted level as close as possible to the same bubble position as the secondary level.
Then at the range align my reticle with a plumb line, noting where the bubble is and adjusting from there.
All level type devices are merely aids to help you eliminate a variable.
 
wild1 said:
I bought a mounting solutions level and so far it seems ok. Totally adjustable and easy to see. Takes awhile to set it up just right but I like it. Here is link. Not sure if any of the companies here sell them. I searched and didnt find any. http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=689346
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Yup we carry them as well. Used them for years.
I just don't like the fact that I have to disturb my cheek weld to see that particular level. I could see it working very well on a scout type rifle rig though.
 
I've got a few of the scope mounted types of levels (standard and offset style) as well as the USO level. Hands down the USO level is more convenient and is easier to see without breaking your cheek weld or concentration.

The USO level is well worth the extra money and fine tuning IMHO.
 
Ian Robertson said:
It doesn't matter if the rifle is upside down as long as the level and the scope agree.
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X2


I don't think a lot of people understand that the gun does not need to be level. It can sit at a 30 degree angle for all it matters.

If your US optics level sits a little different from the base WHO CARES!!!

It only matters that the scope and level are the same, does not matter if the gun is tilted to the side. You just can not tilt the scope. That’s why they call it a scope level and not a gun level.

The problem I do find with the US optics is that the shooter has to keep the gun near level. I prefer the gun to sit where it fits me best and not where the scope level tells me to hold it.

Scope mounted levels allow me to hold the gun where I like it and then level the scope.


Dave


Hey Mike, you still with the big H
 
Anyone used the USO Ring Mounted levels? I've got the rail mounted one on my 308 but I must confess that I have never checked to ensure it was truly level. It shoots little wee groups and seems to put them consistently on the centerline all the way out as far as I have shot it so I don't think that I have a problem (maybe I'm just lucky?).

I can see how with a +20 MOA base and given the height from the centerline of the bore with most of the scope and ring combinations we LR shooters use, that having the rifle not perfectly vertical when the shot is fired would have a measureable effect at distance. For sh*ts and giggles someone should try taking their perfectly levelled rifle and scope out and shooting a group at 300m (picked for convenience as most ranges only go that far - Rick can do it at 1200 for us) then shoot a group with it at a 90 degree cant (not sure how you'd support it neutrally without effecting the harmonics but that's why I'm the idea guy and no tthe implementation guy!) and see what it does to the POI. Might make for an interesting discussion to illustrate the effect of an unlevelled scope.
 
Dave42 said:
X2


I don't think a lot of people understand that the gun does not need to be level. It can sit at a 30 degree angle for all it matters.




Hey Mike, you still with the big H
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If I'm the right Mike, I am still with the big H, although we prefer to think of ourselves as Sperry. 9 years now of vigorously punching a calculator and thinking about the angle of the dangle 20 hours a day.


Sometimes we take a point to to extremes to to prove it, but when taken to extremes they don't hold up. This is the case with your 30 degree cant example. This is entirely for fun, btw, just a chance to dust off my math and have a little fun with it.

Given a 1 1/2" line of sight above line of bore the Sine of 30 is .50 so .50 X 1.5= .75" of horizontal displacement of the line of bore to the line of sight. This being Precision Rifle it's safe to assume that you're not going to be happy with a 3/4" windage error so lets say you dial in your 3 clicks of windage to get your 100 yard zero. This introduces a 3/4 minute of angle converging then diverging angle into the system. This angle will not, and cannot go away. The 3/4 minute will come back to haunt you at 200 yards by being displayed as 3/4 inch error on target. I know that 3/4 minute at 200 is 1 1/2" but half of that started on the opposite side of the line of sight. That's OK, because you get it back at 300. 3-2 x .75= 1.5".

Just as a pure trig function the horizontal error is:

.75" at 200
1.5" at 300
2.25" at 400
6.75" at 1000.

Doing the same test to a rifle lieing on it's side but properly sighted in would exactly double the numbers, since the Sine of 90 is 1.

There is another factor which complicates things. The bullet moves 3/4" sideways in whatever the time of flight to 100 is. This movement is independant of the forward motion, and doesn't change very much even as the velocity slows. Because of this, the error magnifies as distance increases and velocity slows.

I'll use some TOF numbers that I pulled from a ballistic calculator. They happen to be a 168 grain boattail at 2700 fps.

The TOF is .12 second at 100 yards, and the correction is 3/4". The TOF at 1000 is 1.66 seconds, so it roughly follows that the drift has to be 1.66 divided by .12 times .75" for a total of 10.37" horizontal error caused by a 30 degree rifle cant with a vertical crosshair. Sighting in so the bullet path impacts 3/4 to the opposite side of the cant at 100 would hold the error down to that 3/4" all the way out, but who will sight in that way?

Ian Robertson's upside down rifle example would work, but seems like a clumsy setup. Would you stand on your head to shoot it?:D
 
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BigUglyMan,
A rifle fired on it's side would have double the horizontal error of the 30 degree example above and would hit very low, since the barrel would be horizontal and the bullet would do nothing but drop right out of the muzzle.
There is a vertical component to the 30 degree cant as well. The Cosine of 30 degrees is .866 so for the bullet to meet the line of sight at 100 with a scope mounted 1 1/2" above line of bore the bullet would travel .75" to the side and only 1.29" up instead of the 1.5". With a bit of rounding that is about .25 MOA of vertical error. Proving it by shooting would be beyond my abilitiy at this time.:redface:
 
When I mounted my USO level it was reading wrong. I took the level out of the bracket that it mounts into and noticed that when it was machined the milling machine can not cut right up to the corner so the swing out level was being forced down. I carefully fixed the area where it was rubbing and it works like a charm now. I also had the scope out of the rings and remounted that. No more dialing windage on calm days. The only bad thing was finding out that I've got a canted reticle Leupold.
 
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