Firearm & Gun Forum -

Firearm & Gun Forum - (
-   Optics & Mounts (
-   -   removing scope (

redscho 07-26-2014 07:15 PM

removing scope
After a scope is sighted in on a particular rifle then it is removed (mounts loosened) and slid of the rail, how far will it be off when reinstalled?
Rifle AR-15 with top rail. Scope Nikon 223 3 X 9, mounts Nikon P Series.

Highpower 07-26-2014 07:42 PM

Could be anywhere really. That is where a good collimator comes in handy. Once the rifle has been sighted in, check the cross hair location on the grid and write down it's coordinates. Then if the scope is later removed and re-installed, just re-attach the collimator and make sure it points to the same spot as before. If it doesn't, it's easy enough to dial in the scope again until it is.

SSGN_Doc 07-26-2014 07:51 PM

No hard and fast answer. Sometimes they are pretty close to where they were. Sometimes they are off paper.

Axxe55 07-27-2014 11:11 AM

a lot would depend on the mount and the rings themselves. i am sure some would hold zero much better than others. cost of those would probably be the best factor to consider as IMO the higher the quality, the closer they would should return to sero when remounted.

Sniper03 07-27-2014 02:47 PM

And as Axxe stated quality makes a big difference as well as little things like what were the mounts torqued to on the first location before removal and is it torqued to the same on the new installation? Then there is the aspect of what is accurate to one person, is not accurate to another. Some might be happy that after it was re-mounted if it was within a 4" group at 100 yards for example.
For me the group would have to be dead on at 100 yards and within 1 MOA.
So that is a factor also! From my experience most of the time if you re-mount a Scope leaving the rings on it and just re-titening the Rings or Mount to the Base Mount with the same torque specification you normally will be within 3" to 4" at 100 yards. Then you just have to tweek it to get it back on where it was before.


Axxe55 07-27-2014 02:52 PM

another point i'll add is this, that to return to zero when replaced requires a certain amount of precision that cheap can't achieve IMO. this would be one of those types of items where you get what you pay for. to design and manufacture an item that is capable of doing so out of quality materials cost money.

JonM 07-27-2014 08:40 PM

use an adm (american defense manufacturing) quick detach mount. they return to zero so long as you attach it to the same rail location and push forward while attaching everytime.

i use adm's exclusively. i run one on my precision ar15 and cannot detect zero shift. i routinely take the optic off as it helps with cleaning. a 42x bench rest optic is a boat anchor so being able to remove it as needed without zero shift is a big plus

a collimeter will not tell you if zero shift has happened. they are seldom accurate enough to get a rifle on paper.

Highpower 07-27-2014 09:01 PM


Originally Posted by JonM (Post 1610456)
a collimeter will not tell you if zero shift has happened. they are seldom accurate enough to get a rifle on paper.

Never been a problem for me but as they say YMMV. :)

huffmanite 07-28-2014 02:07 AM

Have a fair number of scoped rifles. Seems I'm always swapping scopes around on one of the rifles, or taking one off for some reason and putting it back on. I always expect to re-zero a scope that went back on the same rifle. Can't recall ever not needing to re-zero a scope.

Rick1967 07-28-2014 02:31 AM

I have a flat top upper on my AR. I have my scope mounted to a 1 inch riser. I have a removable carry handle and also red dot. I have swapped back and forth many times. But as long as I put the riser back where it was I have not had to readjust the scope. The riser is the full length of the upper. I only shoot out to 100 yards with it. But it shoots real tight groups...sub MOA.

All times are GMT. The time now is 05:35 PM.

Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.