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Rifle Scopes A couple questions regarding my scope

azhank

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Minuteman
Dec 2, 2009
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Phoenix, AZ
I am shooting a TRG 22 with Nightforce NXS 5.5-22x56 NP-R1. The whole rig is still pretty new to me. I have had her for about 12 months and put roughly 400 rounds of Federal 168gr Sierra Matchking HTHP rounds through her.

I have the scope zeroed in at 100 yards and the zero stop feature has been adjusted to stop there. I am getting more and more pleased with my groups at 100 and 200 and would like to try my hand at 500, 600, 800, 1000.

This is where I am running into some confusion or mainly lack of reading comprehension. In a perfect world my 100 yard zero will put the projectile on the bullseye. I adjust my elevation 1 MOA (4 click) and I am hitting on or near the bullseye at 200. Perfect! This is working out well

Yesterday I gathered some information with my set up. I shot 3 round groups (I know
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) at my 100 yard bullseye and then would crank the scope 1-2 MOA and then repeat. I posted a large sheet of white paper to track the results. At 10 MOA (40 clicks) I was 11.5 inches above my 100 yard zero. 20 MOA (80 clicks) brought me to 22.5 inches above my 100 yard zero. All the way to 40 MOA (120 clicks) came to 34 inches above my 100 yard zero.

Now that I have this great real world data I would like to see where I need to set my dope to reach targets at 500-1000 yards. I was messing around with some ballistics calculators and was given the following:

500 yard, -61.07 drop

800 yard, -217.91 drop

1000 yard, -411.19 drop.


What on earth does the drop mean? Drop in inches or MOA? I realize that we have a sticky that goes over this same question, but I admit that I cant comprehend the answer.

Thanks to anyone who can lend a hand

-Hank
 
Re: A couple questions regarding my scope

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JCH</div><div class="ubbcode-body">have you chronographed your bullets yet? </div></div>

I do not have a chrono. The only info that I have in the 2650 muzzle velocity that is printed on the box of the Federal ammo
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Re: A couple questions regarding my scope

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bward</div><div class="ubbcode-body">The drop you have listed is in inches. </div></div>

Do those numbers seem right for the round?
 
Re: A couple questions regarding my scope

Here's your basic drop table:

Calculated Table
Range Drop Drop Windage Windage
(yd) (MOA) (in) (MOA) (in)
0 *** -1.5 *** 0.0
100 -0.0 -0.0 0.8 0.8
200 -2.1 -4.3 1.6 3.3
300 -4.9 -15.4 2.5 7.7
400 -8.3 -34.6 3.4 14.3
500 -12.1 -63.4 4.5 23.4
600 -16.5 -103.7 5.6 35.3
700 -21.5 -157.9 6.9 50.5
800 -27.4 -229.2 8.3 69.5
900 -34.1 -321.7 9.9 93.1
1000 -42.1 -440.6 11.6 121.5

The first column, after the yards, is what you dial on your scope to hit the target at the indicated range in MOA. The second column is total drop in inches that your bullet actually drops from a 100 yd zero. This column is for reference only.

The third column is drift (windage) corrections in MOA for a 10 MPH wind. The fourth column is in inches of drift. This column is for your reference only.

I used JBM Simplfied Trajectory found here:

JBM Trajectory Simplified

Here is the inputs I used:
Trajectory (Simplified)
Input Data
Manufacturer: Sierra Description: MatchKing™ (Litz)
Caliber: 0.308 in Weight: 168.0 gr
Muzzle Velocity: 2650.0 ft/s
Sight Height: 1.50 in Line Of Sight Angle: 0.0 deg
Cant Angle: 0.0 deg
Wind Speed: 10.0 mph Target Speed: 10.0 mph
Temperature: 90.0 °F Pressure: 29.92 in Hg
Humidity: 0.0 % Altitude: 1117.0 ft
Std. Atmosphere at Altitude: Yes Pressure is Corrected: No
Zero at Max. Point Blank Range: No Target Relative Drops: Yes
Column 1 Units: 1.00 MOA Column 2 Units: 1.00 in
Round Output to Whole Numbers: No

Read it over than shoot out some questions.

Bob