Scope won't hold zero at different distances

G

GC556

Inactive
Hello all,

I recently took my UTG bug buster 3 x 9 scope to the range. I was able to successfully zero the scope at 20 yards. (My range is only 25 yards) I then brought my target to the 10 yard range and began hitting shots about 10 inches low. After some tweaking with the scope I had it zeroed again at 10 yards. With the same settings I brought my target back to 20 yards again and began hitting about 10 inches high. All shots were in a 3inch group, not all over the place.
This is my first scope and I will admit I do not know much about them I have done some research but have not found a solution to the issue that I am having. Hopefully someone here knows what the issue is and will be able to help me correct the issue. Thank you
 
What caliber? How high is your scope from the center of the bore? 3" groups at 20yds is something like 15moa. Could be a lot of things out of whack. What bases and rings did you use? Could also be the scope is no good no offense but utg brand isnt known for quality.
 
It's not changing zero. You're changing distance. The POI will change when you change distances. S'why you have to know where the thing hits at different distances.
Like bacardisteve says, 3" is kind of excessive at those distances. Even for a .22. Assuming it is a .22, of course.
Your UTG Bug Buster 3 x 9 scope is a $100 scope. I think it's an air gun scope too. Not made to go on real firearms.
 
It could also be how you are holding the rifle.
If you are inconsistent, especially with cheek weld on the stock, the point of impact can change.
Also be aware that, unlike using both front and rear iron sights, there's only one point of reference with a scope.
 
I understand this is not a high quality scope but a difference of about a foot off target from only a 10 yard distance change is ridiculous to me. My budget for my first scope was $100 and this one fit the bill. I am using a M&P 15 .556 shooting .223. The scope is mounted very solid. Same mounts the scope came with and utg riser. I was under the impression once I found zero that zero would be at least roughly the same within a 30 foot range.

I'm guessing based on some of the replies that my rifle is way over kill for this scope. There are a bunch of people using this same caliber and scope not reporting any issues though.
 
A 3" group at ten yards is not a group, it's a pattern. I've shot many and many a rifle through the decades, and the worst I've ever had kept groups well inside of three inches at 100 yards. Most were at or under 1" at 100.
 
This -
#3
T. O'Heir
Senior Member

Join Date: February 13, 2002
Location: Canada
Posts: 6,966
It's not changing zero. You're changing distance. The POI will change when you change distances.
Click to expand...
 
Just ran the numbers and 55gr 223 at 3000fps should only see roughly 1 inch diffrence at 10yds when sighted in at 20yds with a 2.25 inch scope height. Your scope has adjustable parallax but even if it was set way off I dont think you would see a 10 inch diffrence. What are the scope rings tightened to? Its possible to over tighten them and literally crush the internal workings. How did this rifle shoot with iron sights?
 
I agree with what bacardisteve said.
Sight in 1.5" low at 20 yards. You should be about 2" low at 10. Experiment with the ao.
 
This rifle has always been extremely accurate at all distances with the stock sights. I'm going to re mount the scope and get a more solid elevation coushin go back to the range next week and hopefully get some more accurate information / have better luck with this thing.
 
Stock sights (iron) are closer to the bore.

A scope in higher above the bore.

The line of sight is different.

This changes trajectory of the bullets.

If you sight in at the closer yardage , with the bullet hitting above the aiming point, at a longer yardage, bullet impact will be even higher .
 
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It's an AR. The iron sights are high. The scope should be the same height as the irons.
If there is something about the scope that makes the POI change by 10" at 10 yards, the scope is broke.
 
Scopes are like that. Gravity affects drop as you extend different range. Some scopes give step down mini-rings to compensate for 100 yd. adaptations. The barrel mussel must be brought upward for the down pull of the distance.

Go to the 100 yd., 200 yd., 300 yd. range with secure lock down stand. Shoot 3-5 rounds at the bull's eye. Without moving the stand, adjust your scope towards the center of the bull's eye in distance "clicks" without moving the rifle.

Begin with 50 yrds. to start. Adjust to the distance by clicks of by markings in the sight of the scope.
 
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Does this rifle have a carry handle? More to the point:How high is the line of sigt above the bore?

You may need to figure out the Trig/math/triangles relative to the distances you are shooting.

I don't know anyone who sights in at 10 yds.Try 25 yds.Then back up to 100 yds and see what you get.Then sight it about 2 in high at 100yds.

If you are steady on a bench or prone with a bipod,I would expect a mediocre used GI parts bucket kit gun with a bargain "AR Stoner" barrel with off brand surplus ammo to shoot inside 5 in at 100 yds,and more likely three in at 100 yds.

Three inches at 10 yards is about right for a cheap pocket handgun.

IMO,if you aren't getting a group the size of a golf ball at 10 yards with a rifle ,darn near any rifle,there are other problems to identify and solve before moving on to sighting in.

Most sound rifles will shoot inside 4 in at 100 yds.
 
Stop wasting time and ammo trying to zero a rifle at 10 yards. Zero it at 100, then find out where it hits at 10-25 just so you'll know. The higher the scope is above the bore the more problems you'll have at close range. Even the best flat top AR's have the scope mounted higher than most sporting rifles. 10" seems like too much difference at 10 yards vs 25, but the difference could be significant. I know that with a 25 yard zero it is very easy to shoot way over a target at 100-200 yards even with iron sights on an AR. The problem is magnified with optics mounted even higher.

If you zero at 100 you're going to be quite low at 25 or less. But but not as far off as you'd be at longer ranges with a 10 yard zero.
 
Two things going on here. One is about distances and points of impact. The other is about group size.

Regardless of POI, some factor is causing very poor groups.
 
Have you put it in a bench rest, and try to take the human element out of it? if it's 'spraying' from a bench rest, it's a different problem.

At 20 yards, I'd expect a much tighter group than 3 inches.

Is there a chance that the scope isn't firmly mounted, or is somehow moving? Or has X MOA slope with respect to the barrel?

How does it shoot off the iron sites?

Is the scope rail tilted X MOA?

Assuming you're using the same ammo, something isn't adding up.

I have a rifle with a 27 MOA (sloped) mount. If someone doesn't know that when they are shooting it, they will be way off.
 
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