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Old June 14th, 2018, 12:15 AM #41
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The PEPR mount is fine for a 1-Yx scope. But I agree, I would not use one for a long range setup.
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Old June 14th, 2018, 08:10 AM #42
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Quote:
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Except the scope does not need to be leveled to the rifle.

The scope needs to be leveled to the world, when you are shooting it (normal hold).
Quite true, good point.

Really just offering a cheap alternative to the scope leveling kits out there, which cost a lot of money and do the same thing as a deck of cards. Most people will take their new rifle / scope to a gun shop and have the scope leveled to the rifle, and it's a pretty easy job to do yourself.

Different from putting a leveling bubble permanently on your scope so that you know that the reticle is plumb to the world when you take your shot, which as you shoot further out makes more and more of a difference.

Connected issues. One can either build their position to fit the rifle, or fit their rifle to their position. The second is a arguably a better choice as your natural point of aim will not be effected as much.

For me, I like to level it to the rifle because if I shoot from different positions, I don't have the same check weld and I find it more difficult if my scope is canted to where it would more naturally fall if I'm in the prone.

But your point that the reticle should be plumb to the world (and not the horizon) when the shot breaks is well taken.
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Old June 14th, 2018, 09:19 AM #43
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Quote:
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Poor man's scope leveling trick...take a feeler gauge
...
It might not be as precise as the scope leveling kit / bubbles
Its likely more accurate than 99% of people levels. You can pretty much guarantee the adjustment mechanism is square to the housing. The reticle could still be mounted canted and it would work right.

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Except the scope does not need to be leveled to the rifle.

The scope needs to be leveled to the world, when you are shooting it (normal hold).
I don't think this is correct. If the scope isn't in the same vertical plane as the rifle AND square then any distance change will introduce windage errors. Negligible at 100m but at long distance the errors add up quick.
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Old June 14th, 2018, 09:28 AM #44
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Originally Posted by smdub View Post
Its likely more accurate than 99% of people levels. You can pretty much guarantee the adjustment mechanism is square to the housing. The reticle could still be mounted canted and it would work right.



I don't think this is correct. If the scope isn't in the same vertical plane as the rifle AND square then any distance change will introduce windage errors. Negligible at 100m but at long distance the errors add up quick.
https://www.youtube.com/watch?v=eCoHG23TQcY

The rifle can be canted, as long as the scope is level. The most important thing is if you are using a bubble level that the bubble and the scope are leveled perfectly. You could mount the scope on the bottom of your rifle and it wouldn't matter if your scope is leveled perfectly.
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Old June 14th, 2018, 10:50 AM #45
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You could mount the scope on the bottom of your rifle and it wouldn't matter if your scope is leveled perfectly.
Underneath is fine. I said scope/bbl in same vertical plane. Below is still vertical

So taking your example to only half as extreme, hold the rifle sideways (vs upside down.) Typical height over bore on an AR w/ a big scope is 3"-ish. If you zero at 100 yds, at 1000yds you'd be 30" off windage. The sine error is small for small angles and may be smaller error that you and/or the gun are capable of but to say "it doesn't matter" is wrong. FOr a gun tha is tilted you actually need to set point of aim @ your zero distance to be the same as the horizontal mechanical offset and not on the crosshairs. There is a reason that precision stocks have adjustable drop/offset/cant buttplates.
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Old June 14th, 2018, 11:56 AM #46
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You guys are hurting my head. Maybe if I get my range set up this summer I can have a help me setup my rifle/ MDS range day.
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Old June 14th, 2018, 09:59 PM #47
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Quote:
Originally Posted by smdub View Post
Underneath is fine. I said scope/bbl in same vertical plane. Below is still vertical

So taking your example to only half as extreme, hold the rifle sideways (vs upside down.) Typical height over bore on an AR w/ a big scope is 3"-ish. If you zero at 100 yds, at 1000yds you'd be 30" off windage. The sine error is small for small angles and may be smaller error that you and/or the gun are capable of but to say "it doesn't matter" is wrong. FOr a gun tha is tilted you actually need to set point of aim @ your zero distance to be the same as the horizontal mechanical offset and not on the crosshairs. There is a reason that precision stocks have adjustable drop/offset/cant buttplates.
I guess you misunderstood. What I meant is that the rifle can be in any orientation as long as your crosshairs are leveled to the ground with the elevation turrets facing up. When the bullet leaves the barrel gravity will do its thing. If your scope is canted and you adjust for elevation or use holdover to compensate at further distances your impact will be off left or right depending on the cant. As long as your zero doesn't change and you keep your scope level every shot, the cant of the rifle is irrelevant.

Did you watch the video?

Last edited by Bountied; June 14th, 2018 at 10:10 PM. Reason: typo
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Old June 14th, 2018, 11:25 PM #48
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Quote:
Originally Posted by smdub View Post
Its likely more accurate than 99% of people levels. You can pretty much guarantee the adjustment mechanism is square to the housing. The reticle could still be mounted canted and it would work right.



I don't think this is correct. If the scope isn't in the same vertical plane as the rifle AND square then any distance change will introduce windage errors. Negligible at 100m but at long distance the errors add up quick.
It is correct.

Say the center of the cross hairs are 1 inch to the side. Say to the right.

If you zero POA=POI at 100 yards, then at 200 yards, you will be 1 inch off to the other side (left). 2 inches at 300 yards, etc. So 9" at 1000 yards.

For my .308 load, 1 MPH change in the wind speed (or mistake in wind call) is 10.6 inches.

Or, you can sight in such that at 100 yards, the bullet impacts 1 inch to the right of the POA. And at 200 yards, it will still be 1 inch off, and at 1000 yards, still 1 inch off.

And a 1 inch offset is HUGE. You are looking more at 1 - 2 tenths. So you are off by 1 - 2 inches at 1000 yards. If this is too much for YOU SHOOTING YOUR RIFLE, I tip my hat to you.

And the errors for having the retical canted, and dialing in an elevation change are MUCH greater than that.

https://www.riflescopelevel.com/cant_errors.html

If you have your reticle canted 3 degrees, that works out to about 24" to the side due to the cant, versus 9" for having a 1" offset to the scope.

BTW a 3 degree cant is moving the reticle about 0.1 inches from the vertical centerline. So you are going from a 0.9" error at 1000 yards (offset) to a 24" error at 1000 yards (cant). 27 times the error. Which one would you prefer to have?

http://www.accuracy-tech.com/scope-level-necessary/
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Old June 15th, 2018, 11:05 AM #49
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Quote:
Originally Posted by Pinecone View Post
It is correct.
It isn't correct and you just used the EXACT same types of examples as I did to prove it. I even mentioned the sine angle error will be typ small.

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Which one would you prefer to have?
I am aware of scope cant error. I can do that math too. You know it doesn't have to be an either/or proposition. There is also a neither option.
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Old June 15th, 2018, 11:47 AM #50
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I think some diagrams might be helpful.
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