View Full Version : Scope Install Question

August 1, 2011, 11:54 AM
I can understand why a scope mounted close to the bore is reasonable. But what about being as far forward as possible or practical?
Is there a reason why this might be desired? I can only think that eye relief might be the reason. But is there some sort of aiming benefit to having a scope forward as much as can be allowed?
My application is this: I swapped a scope on a 20 gauge slug gun for deer season and am setting it up now in the shop. The size of the scope and height of the rings permit me to have a choice placing this scope to the rear or to the front on the base I have.

August 1, 2011, 12:12 PM
How far forward you mount it is entirely dependent on the eye relief of that particular scope model. You can buy EER (scout) scopes that mount way up on the barrel. How far forward or rearward you mount it doesn't affect accuracy.

Mount the scope in the rings with just enough tension on the ring screws to keep it from sliding around on its own but not so much as to prevent you from sliding it with your hands. Close your eyes and mount the gun just like you would like to shoot. Open your eyes and see if the eye relief needs to be adjusted in or out. Keep doing this until you can open your eyes and have the scope perfectly in focus without having to adjust your cheek position on the stock. That is where you lock it down (after leveling of course).

August 1, 2011, 12:36 PM
+1 for Doyle's answer!!!!!!!!

August 1, 2011, 01:18 PM
Ok, so being forward is just a matter of eye relief. And if suitable eye relief is obtained being either position forward or rearward, should not matter- correct? Being forward does not mean you have any better aiming advantage-right?
Thanks for the replies. I've got it set and will attempt zeroing at the range in the morning.
Background: I got nowhere trying to zero a Leupold shotgun scope on my H&R 20ga single shot using very good quality ammo. My present thinking is the scope cannot hold zero, so I am going to retry using a different scope. Since the new scope needs taller rings, it gives me the option to favor the rear or front of the base. I checked eye relief like you guys say and it is fine when set forward. I have good clearance between the hammer and scope.

August 1, 2011, 01:33 PM
Proper eye relief starts by getting a good hold/anchor and cheek-weld position. Then and only then, look into the scope. Ideally you want a position that provides you with the max field in the eye piece. You will notice that this field will increase or decrease as you move the scope forward and back. You can settle on a position that best suits you. Once you get the max field inside the eye piece, you can measure from the back of the rear bell to your eye and get the measure. Just don't poke yourself in the eye !!! :D

Be Safe !!!