Quick and dirty scope setup

[scotton]

This has all been said before, but while I'm in the process of setting up a new scope I thought I would document the process to possibly help newer shooters. The order is more important than the way I do the particular steps.

Step 1 - Put the scope on the rifle and get it "eyeball" level.
Step 2 - Check the eye relief. Move the scope back and forth in the mounts until the eye relief is correct.
Step 3 - Focus the eye piece. Use a blank wall or open sky and get the cross hairs into perfect focus. Then tape the eyepiece focus ring down with electrical tape. You don't want that to change.
Step 4 - Get a rough optical center. Find the center point of adjustment for the turrets and get the zero pretty close to it. The short way I do this is to get the scope set to the middle of the turrets, then click down to where the 11 yard setting would be and take some shots in the house at 11 yards. Sometimes it's close out of the box, sometimes you will need to shim the rings or use adjustable mounts. Whatever you need to do, get the scope to a reasonable optical center. I try for within half an inch.
Step 5 - Make sure the scope is centered over the bore. I set up a mirror at 5 yards and set the scope to 10 yards. Put the cross hairs on the center of the bore and look for the top line of the crosshairs to bisect the objective lens. Adjust the scope as needed.
Step 6 - Set the bubble level. I have a plumb bob set up behind my indoor target, so I get the crosshair on the plumb bob and move the bubble until it is level.
Step 7 through infinity - Zero your gun at your desired zero range. If shooting field target, figure out your near and far hold overs or clicks. Get your yardage marks on your scope wheel.

Once you get everything perfect, shoot it once and buy a new scope. Return to step 1. (Just kidding, I tend to hang on to scopes longer than I probably should).

 

[starlingassn]

dude,you just described my daily activities
HAHAHAHAHA

 

[scotton]

Mine as well, at least for today.

 

[JungleShooter]

This has all been said before, but while I'm in the process of setting up a new scope I thought I would document the process to possibly help newer shooters. The order is more important than the way I do the particular steps.

Step 1 - Put the scope on the rifle and get it "eyeball" level.
Step 2 - Check the eye relief. Move the scope back and forth in the mounts until the eye relief is correct.
Step 3 - Focus the eye piece. Use a blank wall or open sky and get the cross hairs into perfect focus. Then tape the eyepiece focus ring down with electrical tape. You don't want that to change.
Step 4 - Get a rough optical center. Find the center point of adjustment for the turrets and get the zero pretty close to it. The short way I do this is to get the scope set to the middle of the turrets, then click down to where the 11 yard setting would be and take some shots in the house at 11 yards. Sometimes it's close out of the box, sometimes you will need to shim the rings or use adjustable mounts. Whatever you need to do, get the scope to a reasonable optical center. I try for within half an inch.
Step 5 - Make sure the scope is centered over the bore. I set up a mirror at 5 yards and set the scope to 10 yards. Put the cross hairs on the center of the bore and look for the top line of the crosshairs to bisect the objective lens. Adjust the scope as needed.
Step 6 - Set the bubble level. I have a plumb bob set up behind my indoor target, so I get the crosshair on the plumb bob and move the bubble until it is level.
Step 7 through infinity - Zero your gun at your desired zero range. If shooting field target, figure out your near and far hold overs or clicks. Get your yardage marks on your scope wheel.

Once you get everything perfect, shoot it once and buy a new scope. Return to step 1. (Just kidding, I tend to hang on to scopes longer than I probably should).

Now, how in "the new AGN" do I express my deep appreciation for this excellent post?

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Moderator,
I'm sorry, but the little thumbs-up emojis are cute and I use them — but they do not do justice, they are too easy, too impersonal —
they are too "light" to be a truly meaningful expression of my appreciation.

And the comment I will write here will get buried under the new posts in a couple of days....



scotton,
Your guide to scope-setup is plainly excellent, because it is so plain and simple. Thanks for taking the time to write it out!
I suggest to repost this under a sub-forum that collects guides and instructionals.
Well done.

Matthias

 

[scotton]

I appreciate the kind words, but I am just a dwarf standing on the shoulders of giants. All of this information has been gleaned from this forum and others over the years, I just wanted to put it out there in a quick, easy to read format.

For example, I didn't put in anything about scope height. Some of the longer scope setup guides go into a lot of detail about how to measure the scope height. In reality, I don't care about the scope height because knowing the scope height doesn't do me any good when setting up a scope. When I figure out what my near and far POI is, I'll be tweaking the scope height and BC in the ballistic software to establish my pellet path.

In other words, if 25 yards is my zero and 10 yards is 42 clicks (when tested with pellets), I will change the scope height setting in Chairgun until I get 42 clicks at 10 yards. Scope height value in Chairgun may be 1.91" or 2.21", it doesn't matter. It's just a number.

Then, if 50 yards is 56 clicks I'll adjust the BC in Chairgun until the clicks line up for 50 yards at 56 clicks. Then I'll probably need to adjust the scope height again and go back and forth a bit until the 10 yard clicks and the 50 yard clicks are correct. Then I'll put the calculated scope height and BC into Strylok so that I have a good click chart on my phone (even though I rarely use it). I use BC not velocity because FPS is a real number. I know what the velocity is at the muzzle but finding the velocity at the target is a pain in the butt so I use POI at the far targets to calculate an approximation of BC. You aren't hitting the target with a BC, you're hitting it with a pellet.

The only thing that matters is knowing the trajectory of the pellet and how it relates to the turret adjustment or hold over points on the scope. I've tried the different methods to determine scope height and BC, but real world POI is the only real way to know what your pellet is doing so why bother trying to predict those values.

 

[Airgun-hobbyist]

That is a great tutorial. Using a plumb line to establish a square scope cross hair and mounting a permanent bubble level is just about the most important thing to do on a new scope. Then that scope can go on any rifle, so long as you mount the scope so the cross hairs and turret are directly over the bore.

Here's a picture from a member here who shows diagnosis of cant errors.

 

[scotton]

I agree, a scope that is level to the horizon but not in line with the bore can give you fits (or vice versa). A month ago I was having some issues at 50 yards on a gun where I knew the scope was set up properly, but it kept giving me cant-type issues. Finally realized the bubble in the bubble level had gone bad, it kept getting stuck on the right side. Replaced the bubble and everything is good.

 

[bigHUN]

A great tool, I would recommend it. I have seen one from Brownell (they asked me $80 +65 for shipping across the border and I said...you don't want to know) the other (below) was out of stock just everywhere.

I ended up printing my own, and this what I found out:

This is a result of an offset in the elevation block where is the ring clamped, so the scope was parallel to the bore but offset to left.