Properly Setting Scope Ocular Focus ~Achieving CRISP~

[USNAVYCHIEF(Ret)]

So...an Army Marksmanship Unit instructor during the CMP New England Games in Vermont recently revealed something regarding ocular/reticle focus.

One of their better competitors (AMU), recently had an epiphany regarding reticle focus.

The AMU is all using Night Force scopes, top of the line optics.

Everyone was instructed in reticle focus and it's importance, but....some found out they were doing it wrong.

Long story short, an agressive turn on the focus knob, brought that shooters reticle into better focus.

Most scopes come with directions on how to accomplish this, and it is pretty much all the same.

However, most scope manufacturers directions do not stress exactly how critical and important this is to accuracy.

Here is how I do it, and it seems to be working.  It takes awhile, about 1/2 a day, so if you want to do this start in the morning and you should be done by noon.

Make sure you are hydrated, and your eyesight is at it's best.  Preferred to do this on a Sunny day if possible.

Set scope positioning up the evening prior so there is no grey and a CRYSTAL CLEAR, and IMMEDIATE sight picture for the positions, paying particular attention to sight picture in seated and prone.  It likely will not be CRISP, as that is what we are about to accomplish.

Once the scope is set fore and aft, and is level now we can start the process of reticle focus.

1.  If your scope is variable, set it to its highest magnification, if it has a parallax adjustment, set that to inifinity
2.  This can be done in the standing position, as long as you will maintain the same cheek weld as you would for prone.
3.  Loosen the lock ring for focus if you have one (hopefully you do, although many scopes are friction adjust)
4.  Go outside, and shoulder your rifle for standing looking up at the bright sky (the blue portion preferably), do this with your eyes closed.
5.  Inhale/Exhale relax, and then open the eyes, is the reticle focused?  It is not...trust me it is not and if it is buy a lotto ticket

- Here is where the AMU tip comes in-
6.  Make an aggressive turn, over 1/2 a turn on the focus knob.  Repeat step 5, but only once....and ask yourself, is it focused better?  If it is....write that down, so you can remember the direction you turned the knob and write down "better".
7.  Take a 15-30 minute break, stay hydrated
8.  Come back after 15-30 mins, and repeat step 5, is it better?  Take rifle down, make another agressive turn in the same direction and repeat step 5 again, is it better?  If yes....write that down, if no....write that down.
9.  Repeat step 7
10.  Repeat step 8
Once you find it getting worse and not better.....stop and repeat step 7.

Now, make "minor" adjustments and repeat step 5 over and over, this may take 3-5 times to get it PERFECT, and PERFECT is what you are after here.

The point is, most (myself and that AMU shooter included), made an agressive turn, thought that is good and then made very minor turns and called it good.

The AMU shooter found, that an agressive turn brought that reticle into better focus.  This is tough to explain, you really have to see it, but the reticle for me gets darker and more defined, that is the focused reticle.  When it is lighter/thinner, it seems OK, but it is not ideal.  Some glass has writing in it as well, like the VORTEX Viper PST 1-4, I want a dark reticle where I can also clearly read the writing (even though the writing is small).

Now you have accomplished the CRISP part of the scope sight picture.

Get a white sharpie, or something to use to make a witness mark....but do not mark it just yet.

This is a BONUS/Extra step for those optics with side focus or an adjustable objective, and it will remove any hint of parralax.  Especially in low power variable optics.  I got this next tip, from MARCH USA, March scopes are known to be one of the best available.  *If your scope does not have a side focus or adjustable objective, skip this next step, lock down your lock ring if you have one, and then mark the ocular with witness marks.  I use 2-3 markings, as they can wear off*

For those with a side focus/AO:

Get an Appleseed Squares Target
Post that up at 25 yards (I use my backyard for this)
Lay down in prone and establish the position
Adjust the side focus or AO for 25 yards, and continue to adjust it till the target is in its best focus

Now.....
Bob your head on the rifle and check for parralax (google this if you do not understand what I am saying here)
If you see the slightest hint of parralax, a very minor turn on the OCULAR/RETICLE focus is in order...this can be less than 1/4"
Bob your head again and look for parralax

Repeat the above, until any perceived parralax is removed, and the reticle is still CRISP with a perfectly focused target.

Now you have removed any chance of parralax ever becoming an issue.

Now...LOCK the ocular ring and mark it so you can tell if it ever moves.

Taking the time to perform all of the stuff above, will help you to be repeatable with your rifle/scope system.  It takes some time, and discipline to do this, but it is well worth it.

When I am shooting 600 yards slow prone, often times I get worn out, it will drain you physically and mentally.  Especially with eye strain.  I know what a  CRISP/CLEAR and IMMEDIATE reticle looks like....and often times as I get wore out I see a different reticle that is not CRISP.  Simply looking away at another object for a few seconds, and blinking a few times usually brings that CRISP reticle back.  I won't take a shot if my reticle does not look CRISP, yes...I'll hit the target but it will not be a 10 most times.

Give it a try, you may find out like that AMU shooter that your scope was way out of focus and you were accepting something less than ideal/perfect!

R/
Chris