Posted: 1/28/2010 1:37:38 PM EDT
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ok I am confused. I am tyring to get a scope on my 22 to go killing some tree rats. I have a very limited distance I can site it in at. about 20 feet.
so I am siting it in, however I have hit the limit of the adjustments on my scope and I still have about 2" that I need to move the POI up! what is my problem here? is the .22 still on it's way up at that distance? my scope is really low to the reciever, can't even get the cover on it. are my rings to low? they are cheap weaver rings so I know there is no MOA slant in there and I don't have them backwards (do I?). they are $10 weaver high rings from walmart. (it's a .22 remember) also I know I am turning it the right way b/c I turned it the other way like 5 full turns and it went down further. any ideas? |
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I've always been told to zero my .22's scope at fifty yards or at least 25 .
I think the average drops three to five inches in 100 yards...so it's possible from my point of view that it'd still be rising at 20 feet. I think you just need to find a better distance or something. |
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If I had a 50 yard distance to shoot at I would site it in at that distance. But until I can get to the range 20' is as far as I can get with out the cops getting called.
So the rings are really low, I have to really get my cheek to the stock to line it up. Would that really cause it? Any way to tell for sure? (with out going further than 20') Posted Via AR15.Com Mobile |
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I don't think there's anything wrong with your setup. It's likely you're not going to be able to get your scope to zero that low as it's probably bottoming out in the erector.
Think of it like this. 1 MOA is about 1" at 100 yards. So at 20 feet, 1 MOA is .06". So to bring the crosshairs down to a 20' zero, you'd have to crank your scope down 16 MOA. It probably just doesn't have that much adjustment. If you were able to get a zero at 50 yards, you'd find that when shooting at 20 feet the bullet impact would be low. How low depends on the height-over-bore of your scope. It's probably around 1.5 to 2 inches. So if you're hitting 2" low at 20' you're probably zeroed around 50 yards. |
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From what I can find in a quick search - Try 3/4" low at 21 feet.
In other words, at 21 feet zero the scope at a point 3/4" above where your bullet impacts. This should put you in the general vicinity of POA at 50 yards. Between about 50 feet and 50 yards you will be striking high (max of about 1/2"). Of course this is all theoretical, charts and graphs and stuff. I prefer to do my calculations on paper with a lead pencil. 
ETA: I just noticed you said "High Rings." The data above may or may not work with high rings. 
High rings are not a good choice for short range zero, you're just aggravating the situation. A lower set of rings may be necessary. |
Quit shooting inside your house and you won't have that problem Seriously, as others have stated... your simply too close, way to close.
You are going to have an offset btwn point of aim/ point of impact the closer you are to the target. Measure from the center of your bore to the center line of your scope tube (height over bore as someone else stated). At 20ft you probably can't expect to get much higher than that. If you can adjust your scope that much, then when you go to shoot at 50 yards you're going to be way high. 50 yards is still almost 7 times farther than where you are zeroing at 20 ft. Even left to right adjustments may appear zeroed at 20 ft, but when you shoot at a further distance you may find they are way off. Do you know how to bore sight a rifle? If you can, try bore sighting at 50 yards then try shooting closer to adjust your left/ right if it's way off, but don't change elevation. eta: just saw your post saying 2-3" high. What kind of .22? AR? |
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Quoted:
it's a spike's upper. I am going to give up on the sighting in at 20 feet. oh well. I did bore sight it but only at 20'....... I had a bore sight kit but can't find it now.... :( On an AR w/ high rings, you are looking at ~2.5" height over bore, so there's nothing wrong w/ the gear
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Running out of adjustment on your scope should have almost nothing to do with the height of your scope rings, within reason. What it probably means is that you're setup is slanted, the scope isn't parallel to the bore.
First thing I'd try is to swap out the rings front/back and see if that matters. Probably the rings are out of spec or possibly the scope tube itself. Edit to add - I'd probably bore sight at 50 yds before I'd sight in at 20 ft. |
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that was the ticket. I measured it out, then measured it out on the target. shot again and had to move it WAY down. (almost 5 full turns)
now I am getting them right where I expect them to be. tomorrow I will be able to try it out at 50 yards and see how close I am. |
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Quoted:
Off by 1 foot? Huh? Though I was thinking .22 bolt gun with a height over bore of 1-1.5", rather than an AR with a h.o.b. of 2.5-3. Yeah you guessed a 20 foot zero to be on at 50 yds, when it was actually 21 feet.... I'm still hurt thinking about it.. 
This would be a good way to start getting used to holdovers and estimating impacts based on known range trajectories, so it could be a little tool in disguise. Run with it as is and develop data as time permits. |