Scope adjustment WAY off

elwopo · September 23, 2012, 05:48 PM

Hi,

Just mounted a scope on a SCAR and something is wrong getting it sighted in.
Scope is a Buckmasters 3-9x40. Mount is Nikon M-223 1-piece designed for AR style rifles with rail. Scope, mount, and rifle are brand new.

Mounted the scope and put the rifle in a vise (yes....a gun vise....lol). Used the Weaver tool (small bubble levels) to level the rifle then the scope.
Went to the range and first shot was a little low but about 1.5 feet to the left.
Had to adjust the scope as far to the right as it would allow....and now it's about 3/8" to the left still....and the scope won't adjust any farther.
Asked the guys who work at the range if they've ever heard of this or what the problem might be.....and they didn't have a clue.
So now.....I'm asking you guys.

Thanks in advance.

**4V50 Gary** · September 23, 2012, 05:56 PM

Is the rear scope base tightened down by screws that pass from left to right or vise versa? Try loosening one and then tighten the other (if shooting to the left, move the scope to the left - me thinks).

Creeper · September 23, 2012, 06:03 PM

First... re-center the reticle. Using the mirror method, or counting clicks... what ever works for you.
Next, take a really hard look at the mount and rings. It may be that, as 4V50 Gary has alluded to, you've tightened the base incorrectly, cocking it on the rail.
You should loosen all the screws, start in the middle with a light snugging... then slowly apply torque in small increments (no more than about 40 in.lbs is needed max)... again, from the center out.

Good luck,
C

geetarman · September 23, 2012, 06:06 PM

Take the scope and mount off and take a careful look at ALL mounting surfaces and check for burrs.

If you find some, carefully stone them smooth. If not, remount the elements and see if POI changes.

What you are describing sounds like something interfering with the surfaces mating up.

Just taking the thing off and remounting may make all the difference in the world.

The only other thing that comes to mind is an inaccurately machined base or rail on the rifle. I am guessing the problem is not that. Look for the simple things first.

The fact that everything is new points to junk somewhere in the mounting surfaces.

elwopo · September 25, 2012, 08:49 PM

Not knowing exactly where things went wrong....I went to the basics based on what I learned here.
Took everything off, checked for burrs, used the click method to get to center on the scope (time consuming much?)
Set the rifle in a vise and leveled side to side...front to back. Checked with a laser level (it's an OCD thing). Set the scope on and made sure not to torque the screws into oblivion. Leveled scope with the same laser. Looked through...and the thing is scary dead on side-to-side...and just a bit off top to bottom. I'm guessing that might be due to the 20 moa of the scope mount itself.

My initial problem was probably caused by cranking the screws too much on the base. Greatly appreciate all the input as it led me to looking into the details and setting things up the right way.
Now....some range time should get this dialed in quite nicely.

Creeper · September 25, 2012, 09:09 PM

Good shootin' elwopo... glad you sorted it.

C

September 23, 2012, 05:48 PM	#1
elwopo Junior Member Join Date: August 23, 2012 Posts: 6	Scope adjustment WAY off Hi, Just mounted a scope on a SCAR and something is wrong getting it sighted in. Scope is a Buckmasters 3-9x40. Mount is Nikon M-223 1-piece designed for AR style rifles with rail. Scope, mount, and rifle are brand new. Mounted the scope and put the rifle in a vise (yes....a gun vise....lol). Used the Weaver tool (small bubble levels) to level the rifle then the scope. Went to the range and first shot was a little low but about 1.5 feet to the left. Had to adjust the scope as far to the right as it would allow....and now it's about 3/8" to the left still....and the scope won't adjust any farther. Asked the guys who work at the range if they've ever heard of this or what the problem might be.....and they didn't have a clue. So now.....I'm asking you guys. Thanks in advance.

September 23, 2012, 05:56 PM	#2
4V50 Gary Staff Join Date: November 2, 1998 Location: Colorado Posts: 21,832	Is the rear scope base tightened down by screws that pass from left to right or vise versa? Try loosening one and then tighten the other (if shooting to the left, move the scope to the left - me thinks). __________________ Vigilantibus et non dormientibus jura subveniunt. *Molon Labe!*

September 23, 2012, 06:03 PM	#3
Creeper Senior Member Join Date: September 9, 2008 Location: Woooooshington Posts: 1,797	First... re-center the reticle. Using the mirror method, or counting clicks... what ever works for you. Next, take a really hard look at the mount and rings. It may be that, as 4V50 Gary has alluded to, you've tightened the base incorrectly, cocking it on the rail. You should loosen all the screws, start in the middle with a light snugging... then slowly apply torque in small increments (no more than about 40 in.lbs is needed max)... again, from the center out. Good luck, C __________________ Shoulder Drive Nicholson Club

September 23, 2012, 06:06 PM	#4
geetarman Senior Member Join Date: November 18, 2009 Location: Arizona Posts: 3,157	Take the scope and mount off and take a careful look at ALL mounting surfaces and check for burrs. If you find some, carefully stone them smooth. If not, remount the elements and see if POI changes. What you are describing sounds like something interfering with the surfaces mating up. Just taking the thing off and remounting may make all the difference in the world. The only other thing that comes to mind is an inaccurately machined base or rail on the rifle. I am guessing the problem is not that. Look for the simple things first. The fact that everything is new points to junk somewhere in the mounting surfaces. __________________ Geetarman Carpe Cerveza

September 25, 2012, 08:49 PM	#5
elwopo Junior Member Join Date: August 23, 2012 Posts: 6	HUGE thanks to all of the replies Not knowing exactly where things went wrong....I went to the basics based on what I learned here. Took everything off, checked for burrs, used the click method to get to center on the scope (time consuming much?) Set the rifle in a vise and leveled side to side...front to back. Checked with a laser level (it's an OCD thing). Set the scope on and made sure not to torque the screws into oblivion. Leveled scope with the same laser. Looked through...and the thing is scary dead on side-to-side...and just a bit off top to bottom. I'm guessing that might be due to the 20 moa of the scope mount itself. My initial problem was probably caused by cranking the screws too much on the base. Greatly appreciate all the input as it led me to looking into the details and setting things up the right way. Now....some range time should get this dialed in quite nicely.

September 25, 2012, 09:09 PM	#6
Creeper Senior Member Join Date: September 9, 2008 Location: Woooooshington Posts: 1,797	Good shootin' elwopo... glad you sorted it. C __________________ Shoulder Drive Nicholson Club