Scope Eyebox and positional shooting

[nycnoob]

I am having some trouble with my rifle scopes eye box. I do some
precision shooting (Appleseed and Highpower) and I can not find a
position on the rifle for the scope which gives me the
correct eye box for both prone and offhand. I have taken to
putting my scopes on a rail and moving them an inch or two as I
change position.


I do not understand why I am the only one with this problem. I
have taken Randy Cain's class and the others their had no
troubles with their scope mounts (but the whole class was using
Leopold scopes). I have been to Appleseed events where most of
the shooters were using scopes and they did not need to make
adjustments to their rifle between positions.


For highpower I am using the: Bushnell Elite Tactical Rifle Scope
1-6.5x24mm on a Tikka with an OEM stock.


For Appleseed I am using the Primary Arms 1-4X24mm scope on a
10/22 wooden stock.


I know that for some of these events people get stocks with
adjustable LOP but I was really hoping to stock with a standard
looking "old-fashioned stock" for NYC legal reasons.


Any insight to why I am having issues and others are not, would be
appreciated.

[Rich@CCC]

Deleted to wait for someone with more knowledge/experience to ask the right questions.

[StraitR]

Do you have a large variation in shooting positions that prevent you from putting your cheek down at the same stock location when changing positions? If you get straight behind your rifle in the prone, rifle in-line with spine, but then blade your body when kneeling or standing, that difference will likely prevent you from putting your face down at the same stock location without increasing LOP or shifting the optic forward.

I'm not suggesting the ability to change LOP on the fly as a solution, but rather consider your shooting positions and find some sort of balance between them.

Another suggestion is to find optics with more forgiving eye boxes. Higher magnification, larger variability (e.g. 1-8x/3-15x), and inexpensive "budget" models are common factors in eye box/exit pupil size.

[TAZ]

Not sure about the Bushnell, but I'm not surprised that the PA has limited eyebox. It's one of those things that drop off as the cost drops off. I have a 1-6 ACSS Gen2 on an AR that I had to find a happy median mounting location on. I have to slightly adjust a bit when I switch between prone and offhand, but if you're having to move inches you're going to need a giraffe neck to compensate. Have the same issue with cranking the power level up on the PA. No such issues with the IOR on my 18" AR.

Have you contacted either manufacturer to see what they suggest? I know PA was pretty helpful when I had questions. May be worth an email.

[voodoo_man]

It is very weird that you would have to move the optics from one position to another due to position. That is not standard.

The position of the optic should be figured out in this order:

1. Make sure you install the optic into the mount properly and securely (follow manufacturer instructions and specs)
2. Set the optic on maximum magnification
3. Shoulder the rifle in your preferred position, if you will be shooting prone with this rifle more often than other positions, then shoulder the rifle in a prone position.
4. Loosely mount the optic onto the rail until you do not see any scope shadow/vignette - that means you should start out a little further than you would believe and work your way towards your eye until there is no scope shadow/vignette visible.
5. Set the optic to lowest magnification and make sure there is no scope shadow/vignette.
6. Install the optic onto the rail following all install specs/instructions/etc.

This should work for either eye and any position.

[Clusterfrack]

In addition to VDMs excellent advice, I recommend building a cheek rest for your guns using pipe insulation foam and tape. Without a consistent cheekweld, you're going to be fighting an uphill battle--especially prone.

The best way to do this is to unload, take out your bolt, insert a chamber flag, and have someone look into the front of your scope while you are behind it. Your proper cheekweld is when they see that your eye is centered.

Plus, your homebrew cheekpiece will make you the coolest kid on the block.

[nycnoob]

Cluster,

I have a cheek piece, I use the matthewsfabrication.com http://matthewsfabrication.com/produ...ex-cheek-rest/ on both rifles.
but this is because I have the scope on the Bobro QD mount on the scope so I can move it around.


VDM,

I just rechecked the Tikka, I can not find a place to put the scope so that there is no scope shadow in both positions.
When I am prone I want to move the scope about 4/5 rails forward to get a good view. I have left the settings
in one position (either min/max power) and adjusted prone then stood up and it was like looking down a tunnel.
I know that some highpower shooters move their LOP about 2 inches so this appears to be typical. When we first
installed the cheek rest, we did not read the instructions which were to adjust the rest from prone. so we had to
drill extra holes in the 10/22 stock because the prone cheek weld is far infront of the offhand cheek weld.


I do not have a preferred position. For both rifles I use them in "competition setting" where I will shoot
1 string offhand, 1 string sitting, and then 1 string prone, then put the rifle away.

[voodoo_man]

I would figure out a position to put it where there is no scope shadow probe and then deal with it in other positions, as there seems to be limitations.

Remember the optic does not have to be centered in the mount. It can be a little forward or back as long as the turret posts don't touch the mount rings.

Firing position
Head position
Optic position
Optic position in mount

In that order, yes it means you may need to mess around a bit.

This is much easier on an AR platform rifle or an optic/mount combo which has a lot of room to work with.

[nycnoob]

I would figure out a position to put it where there is no scope shadow probe and then deal with it in other positions, as there seems to be limitations.

I do not understand you last comment. Perhaps some photos will help.
I have been using the rifle in this configuration for a year or so including classes with Randy Cain and some HighPower matches.

[Clusterfrack]

Probably the best way to solve this is with expert help in person. Alignment on magnified optics is fairly precise, even with expensive scopes, and there are 6 degrees of freedom to work with. Let's start with when it's working well. When you're aligned (no shadow), how close are you to the edges of your eyebox? Are you symmetrical? Are you looking out of the center of your eye? Is your head in an awkward position? Someone looking in from the front of your TOTALLY SAFE rifle can help with this. Once you have one good position, figure out how to approach this in other positions.

It may be that your setup isn't going to work. I've had some people show up with scopes so low, they had to tilt and twist their head.

I'm guessing the folks at Appleseed can get you squared away.