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Old November 2, 1999, 06:35 PM   #1
JERKY
Senior Member
 
Join Date: October 29, 1999
Location: GLEN BURNIE MARYLAND USA
Posts: 179
I was at the range last weekend shooting my new marlin .22 rifle. I have a 9x scope on it and i sighted it in at 20 yards.At 20 yards i put em all in the same hole. when i moved to 50 yards it started shooting high about an inch. when i moved to 75 yards it started shooting about 2 1/2 inches high.
When i moved back to 30 yards it was right on target.

Any ideas as to why its shooting higher and higher as i move farther down range ?

Any help is appreciated.

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TIM : )
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Old November 2, 1999, 07:05 PM   #2
Mal H
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Join Date: March 20, 1999
Location: Somewhere in the woods of Northern Virginia
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As you know, a bullet starts falling to earth as soon as it leaves the muzzle at the same rate it would if you just dropped it from muzzle height. If your rifle was absolutely level and the targets were all in line, you would see what you expect to see. If it was on target at 20 yd, it would be low at 50 yd and lower at 75 yd. What you are actually doing, however, is angling your rifle slightly up. So if it is on target at 20 yd, the bullet, still traveling in an upward direction in its arc, will hit the 50 yd target a little higher, etc. If you continued your testing out to 100 and then 150 yd, you would then see the bullet dropping down the targets at a fast rate.
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Old November 3, 1999, 04:51 AM   #3
George Hill
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Join Date: October 14, 1998
Location: North Carolina
Posts: 11,547
MAL is exactly right.
A little .22 has a good balistic arch. - it climbs a good way before it drops - but then when it does - it drops quickly.
This varies according to its Zero.

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Old November 5, 1999, 12:24 PM   #4
Art Eatman
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Join Date: November 13, 1998
Location: Terlingua, TX, USA
Posts: 22,540
Hey, whoa! You're using a scope, right? The axis of the scope is above the axis of the bore, right?

So, sighting in at close range, you are making these axes intersect in order for the bullet hole in the target to be at the junction of the crosshairs on your point of aim. The bullet is "rising" to the point of aim.

After your zeroed distance, the bullet is still rising. At intermediate distances, then, it will be above the line of sight. At some point it will be back on line, and then fall below it.

I regularly start new-sight-in process with centerfires dead-on at 25 yards. This is commonly 2" high at 100, and dead-on at 200. (Round-number generalization)

Later, Art
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