Scope Alignment Opinions

[T-shooter]

I've tried various ways to level a scope. The method I've used for several years is with the EXD tool from Brownells. It centers the barrel and scope on a vertical plane and then I level the scope from the turret caps. A better way would be to use a true vertical line (weight on a string) instead of the level on the caps. It doesn't work on everything because you have to have access to the barrel under the scope objective lens. On an AR, (bottom picture) you'd have to remove the gas tube. On those I set the bottom machined surface of the upper receiver on a level and level the scope to that.

Any other method I can think of doesn't align the centerline of the barrel to the scope. Sometimes, the scope rail isn't exactly perpendicular so not necessarily a good place. Does anyone else use this tool and do you know of any potential problems or a better way to get perfect alignment, especially on an AR rifle?

 

[Rob01]

I have used the scope base for years to show the rifle level and it's worked fine. I level the rifle after the ring bottoms are placed in their proper place and torqued to base and then set the scope in the ring bottoms and with a level on the elevation knob carefully torque down the rear ring and then do the front ring. Has worked for years for me on my match rifles that i have used to shoot to 1000+.

 

[jimbires]

I use the tall target .

http://www.longrangehunting.com/articles/reticle-perpendicularity.php

 

[Rob01]

I tall target check when I check tracking as well as I make sure my target vertical line is perfectly vertical. It's a double check to make sure.

 

[T-shooter]

I have used the scope base for years to show the rifle level and it's worked fine. I level the rifle after the ring bottoms are placed in their proper place and torqued to base and then set the scope in the ring bottoms and with a level on the elevation knob carefully torque down the rear ring and then do the front ring. Has worked for years for me on my match rifles that i have used to shoot to 1000+.

That's fine if the rail is level. I have seen 2 that weren't. For instance, the AR pictured above. I figure the bottom of the receiver is probably the most true surface to go from. When setting it on a level, the rail has a slant, enough to see on a bubble level. I also ran across an old .22LR Savage rifle that was that way. And the stock is also slanted. After mounting the scope, looking at it you would swear the scope is way off but it's not. I shot it at a true vertical line and it tracked correctly to the limits of the elevation adjustment both up and down.

 

[Rob01]

I would venture to say a larger amount are level than aren't. Especially if the rail was mounted properly. If an AR rail is not level then that is a manufacturing issue. None of my ARs have been that way.

If I came across an issue where it wasn't then I would look to a different set up to mount but for the past years the level and way i described above has worked fine.

 

[Richard Coody]

Simple
I use this tool when mounting the scope.

http://shop.brownells.com/optics-mo...V_f5hUYEUlL1WvUZU4t-wg5WH-6N_SnPiNBoCa6jw_wcB

I then hang a plumb bob out there about 25 yrds, Check the rifle level and look at the crosshairs compared to the plumb line. Adjust if necessary.

Sight in

Final check. Tall piece of paper at 100 yrds with a plumb line on it. Make sure you check your rifle level. It must not be.canted for this to work. Shoot and dial. I use 10 moa increments. Dial till you run out of adjustment. They should all be very close to the plumb line. If not back up and punt.

 

[jepp2]

I level the scope from the turret caps.

I am never confident the top of the turret is plumb with the reticle. I have seen it more on less expensive scopes, but I always have my questions. So I use that as my starting point.

I use a magnetic bar with a bubble level on top of the scope base (checked with the top of the ring bottoms), then I sight it on a known level surface (I use brick ledge above a double garage door ~400 yards away). It makes it very sensitive to what is level. Of course if I don't have the rifle level to start with, I'm only level to the cant.

 

[T-shooter]

I am never confident the top of the turret is plumb with the reticle. I have seen it more on less expensive scopes, but I always have my questions. So I use that as my starting point.

I use a magnetic bar with a bubble level on top of the scope base (checked with the top of the ring bottoms), then I sight it on a known level surface (I use brick ledge above a double garage door ~400 yards away). It makes it very sensitive to what is level. Of course if I don't have the rifle level to start with, I'm only level to the cant.

I did use the tool shown above to get the scope and barrel centerlines vertical and then put a weight on a small piece of rope outside against my garage and adjusted my vertical reticle line to it. On my SWFA scope it was 99% even with the top turret cap. I've seen others that were off. I always use a bubble level on the scope when shooting so that I'm holding the rifle correctly. At distance, if it is canted the point of impact will move left or right, especially when adjusting the elevation.

 

[jepp2]

I will share my "worst case" I have experienced. On a BSA scope with the reticle plumb. I sent the 2 scopes back to BSA and they sent them back and said they were within spec. I know, cheap scopes.

 

[T-shooter]

I will share my "worst case" I have experienced. On a BSA scope with the reticle plumb. I sent the 2 scopes back to BSA and they sent them back and said they were within spec. I know, cheap scopes.

View attachment 1014173

My worst was also a BSA. This is the drawing I sent in with the scope. It was well over a year old. They sent me a new one. It was a 1x4 (30mm tube) and I had it on an AR. I assumed it was made correctly and until I pulled it off to put on another rifle and looked through it, I never noticed.

 

[FatBoy]

I use a small spirit level on the base and one on the elevation cap. I always drop a plumb line to check the reticle against the levels. After I level the scope if it won't track strait up and down the plumb line it gets canted until it does. If I had one way off, I'd send the scope back.

I don't worry too much about the scopes being perfectly level with the rifle as I shoot out of a sling and coat so I may cant the rifle a bit. As long as my elevation adjustments don't induce windage, I consider it good to go.

 

[Gina1]

I use a plum line. Making sure the stock/action is level. I then hang a plum line on a 3 foot tall target holder at 70 yards and rotate the scope so the vertical cross hair is parallel to the plum line.

 

[Ggmac]

I will share my "worst case" I have experienced. On a BSA scope with the reticle plumb. I sent the 2 scopes back to BSA and they sent them back and said they were within spec. I know, cheap scopes.

View attachment 1014173

BSA scope shooters , have you ever taken the resettable turret caps off to check the actual turret ? They are retained (caps) by 3 small Allen screws which if not secured evenly will cock/ tilt the caps

 

[T-shooter]

BSA scope shooters , have you ever taken the resettable turret caps off to check the actual turret ? They are retained (caps) by 3 small Allen screws which if not secured evenly will cock/ tilt the caps

Should be easy to check. Secure the rifle with the cap level, then turn it 180 degrees and see it it changed. Turn it back to make sure you didn't move the rifle. Sounds like something I need to check on all scopes with resettable turret caps. Thanks!

 

[Ggmac]

Should be easy to check. Secure the rifle with the cap level, then turn it 180 degrees and see it it changed. Turn it back to make sure you didn't move the rifle. Sounds like something I need to check on all scopes with resettable turret caps. Thanks!

Well at least the ones with Orin's and 3 set screws .

 

[jepp2]

BSA scope shooters , have you ever taken the resettable turret caps off to check the actual turret ?

Nope, but thank you for the information. That is exactly what the problem was.

 

[Ggmac]

Nope, but thank you for the information. That is exactly what the problem was.

Was your reticle plumb but the caps weren't ?

 

[jepp2]

Was your reticle plumb but the caps weren't ?

Yes, that was the issue.

 

[Ggmac]

Yes, that was the issue.

Did you even read the part about the caps not being true and the reason ?
Do with the info as you wish but not knowing how any why things either work or don't is a reason for wasted dollars .