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Jaxom · Senior Member

Now for those of us that have been around for a while...we've seen the question, "how do I sight my rifle scope?" often enough. That I understand and have a fairly good grasp of how to go about doing this.

My question is not a matter of how, but where to set my rifle's zero at. Now I know my stock 2300 will most-likely be fairly accurate out to say 20-25 yards. But like the rest of the tinkers and modder's I'm not happy with just being stock. I've already talked about the bits and pieces I'll be adding to my baby. This will obviously have an affect on the useful range or where I should go about sighting in my zero.

To help make sighting in my zero easier, I just purchased a laser bore sighter. According to the instructions, you are sighting in for a 100yd zero. Which I just know I won't be able to achieve with my 2300 no matter what I do to it. With a 14" long barrel, I just can't see it. 50 or maybe even 60 yards I can see, but not 100!

Now I understand that small caliber ag's have a rather flat trajectory. I don't think the makers of the laser bore sighter took this into account. For a .22 caliber @ 100 yard zero, with the target placed at 10 yards, the cross hairs should be 2" above center. (This is according to the instructions)

Now I wish I was like some of you all that have massive back yards where the deer and antelopes can play....but I don't. Even if I did, up here in the great white north of Chicago, the temps are steadily dropping now, and soon we'll be seeing that ikky white stuff called "snow". So to do any sighting in I'll be stuck down in my dungeon that's only 50 feet long at best.

So, with my modest enhancements to my 2300, (14" barrel, planned disco valve and trigger spring, HPA conversion opperating at 1800psi) where would you put my zero at?

Secondly, just how flat of a trajectory can I expect over distance? In other words, if my zero turns out to be say 65 yards, where should the cross hairs be at 10 yards?

Thanks,

Jax

Slavia · Moderator

Lots of variables there. You'll need to know muzzle velocity (which means a chronograph). Do you have the Chairgun software? That would let you play with different zeros and determine near and far points of impact.

You can come close even without a chronograph. Zero the gun at a close range, and then shoot farther out. Measure how much the group has dropped at the far range. Then plug different velocity values into the software until the charts match what you actually experienced. Then knowing an approximation of velocity, you can change zeros until the trajectory is useful for your kind of shooting.

http://www.chairgun.com/

And some others:
http://www.gun-shots.net/ballistics-software.shtml

rsterne · Moderator

Just an example.... BC of 0.020 @ 800 fps:

HTHs....

Bob

Jaxom · Senior Member

Thanks guys, I just knew I could count on some expert advice. My only issue now is the lack of a descent sized range. Doubt i would get good numbers if I set up a targe at 5 and 10 yards...

Looks like a chrono is in my future. Just have to find a job first!

Jax

donwalk · Veteran Member

you can zero any rifle or pistol for any place/distance you want...especially if you have the big target knobs to aid in adjusting/re-adjusting.

select the scope best for your application, get to know and understand it's calibrations.

if 50 ft is all you have...zero for that. it's a simple matter of readjusting after that once you go outside...

keep a written journal as you go to refer to...