Bullet drop...

[vellnueve]

Probably the weakest point of my shooting is ballistics.

Can anyone give me a rough estimate of how much drop I'll have out of a 1/7 20" barrel shooting XM193? I'm shooting at 200 yards and it's zeroed for 100.

 

[Mike-Mike]

its still on the way up at that point..

ETA: You will hit about an inch high. You can look up a ballistics chart online.

 

[andy t]

You are confusing 50/220 yard zero with the OP's 100 yard zero.
The op will be about 2.2" low.

Here is what I got using http://www.jbmballistics.com:

Ballistic Coefficient: 0.243 G1 Caliber: 0.223 in
Bullet Weight: 55.0 gr
Muzzle Velocity: 3120.0 ft/s
Sight Height: 2.50 in Line Of Sight Angle: 0.0 deg
Cant Angle: 0.0 deg
Wind Speed: 10.0 mph Target Speed: 10.0 mph
Temperature: 59.0 °F Pressure: 29.92 in Hg
Humidity: 0.0 % Altitude: 0.0 ft
Std. Atmosphere at Altitude: No Pressure is Corrected: Yes
Zero at Max. Point Blank Range: No Target Relative Drops: Yes
Column 1 Units: 1.00 in Column 2 Units: 1.00 MOA
Round Output to Whole Numbers: No
Output Data
Elevation: 4.257 MOA Windage: 0.000 MOA
Atmospheric Density: 0.07647 lb/ft³ Speed of Sound: 1116.4 ft/s
Maximum PBR: 343 yd Maximum PBR Zero: 297 yd
Range of Maximum Height: 174 yd Energy at Maximum PBR: 432.5 ft•lbs
Sectional Density: 0.158 lb/in²
Calculated Table
Range Drop Drop Windage Windage Velocity Mach Energy Time Lead Lead
(yd) (in) (MOA) (in) (MOA) (ft/s) (none) (ft•lbs) (s) (in) (MOA)
0 -2.5 *** 0.0 *** 3120.0 2.795 1188.6 0.000 0.0 ***
50 -0.7 -1.4 0.3 0.6 2915.6 2.611 1037.9 0.050 8.8 16.7
100 -0.0 -0.0 1.2 1.2 2720.4 2.437 903.7 0.103 18.1 17.3
150 -0.4 -0.3 2.8 1.8 2533.6 2.269 783.8 0.160 28.2 17.9
200 -2.2 -1.1 5.1 2.5 2354.4 2.109 676.8 0.222 39.0 18.6
250 -5.6 -2.1 8.3 3.2 2182.4 1.955 581.5 0.288 50.6 19.3
300 -10.8 -3.4 12.5 4.0 2017.6 1.807 497.0 0.359 63.2 20.1
350 -18.1 -4.9 17.6 4.8 1860.5 1.666 422.7 0.437 76.9 21.0
400 -28.0 -6.7 24.0 5.7 1711.8 1.533 357.8 0.521 91.6 21.9
450 -40.8 -8.7 31.6 6.7 1572.6 1.409 302.0 0.612 107.7 22.9
500 -57.1 -10.9 40.7 7.8 1444.3 1.294 254.7 0.712 125.3 23.9

its still on the way up at that point..

ETA: You will hit about an inch high. You can look up a ballistics chart online.

 

[vellnueve]

Thanks!

 

[bpm990d]

I came up with -1.89 inches at 200 yards.

ICAO Standard Atmosphere
3200 fps
.120 G7 BC
2.6 inches sight height

B

 

[Bob J]

That is so cool.....

You are confusing 50/220 yard zero with the OP's 100 yard zero.
The op will be about 2.2" low.

Here is what I got using http://www.jbmballistics.com:

Ballistic Coefficient: 0.243 G1 Caliber: 0.223 in
Bullet Weight: 55.0 gr
Muzzle Velocity: 3120.0 ft/s
Sight Height: 2.50 in Line Of Sight Angle: 0.0 deg
Cant Angle: 0.0 deg
Wind Speed: 10.0 mph Target Speed: 10.0 mph
Temperature: 59.0 °F Pressure: 29.92 in Hg
Humidity: 0.0 % Altitude: 0.0 ft
Std. Atmosphere at Altitude: No Pressure is Corrected: Yes
Zero at Max. Point Blank Range: No Target Relative Drops: Yes
Column 1 Units: 1.00 in Column 2 Units: 1.00 MOA
Round Output to Whole Numbers: No
Output Data
Elevation: 4.257 MOA Windage: 0.000 MOA
Atmospheric Density: 0.07647 lb/ft³ Speed of Sound: 1116.4 ft/s
Maximum PBR: 343 yd Maximum PBR Zero: 297 yd
Range of Maximum Height: 174 yd Energy at Maximum PBR: 432.5 ft•lbs
Sectional Density: 0.158 lb/in²
Calculated Table
Range Drop Drop Windage Windage Velocity Mach Energy Time Lead Lead
(yd) (in) (MOA) (in) (MOA) (ft/s) (none) (ft•lbs) (s) (in) (MOA)
0 -2.5 *** 0.0 *** 3120.0 2.795 1188.6 0.000 0.0 ***
50 -0.7 -1.4 0.3 0.6 2915.6 2.611 1037.9 0.050 8.8 16.7
100 -0.0 -0.0 1.2 1.2 2720.4 2.437 903.7 0.103 18.1 17.3
150 -0.4 -0.3 2.8 1.8 2533.6 2.269 783.8 0.160 28.2 17.9
200 -2.2 -1.1 5.1 2.5 2354.4 2.109 676.8 0.222 39.0 18.6
250 -5.6 -2.1 8.3 3.2 2182.4 1.955 581.5 0.288 50.6 19.3
300 -10.8 -3.4 12.5 4.0 2017.6 1.807 497.0 0.359 63.2 20.1
350 -18.1 -4.9 17.6 4.8 1860.5 1.666 422.7 0.437 76.9 21.0
400 -28.0 -6.7 24.0 5.7 1711.8 1.533 357.8 0.521 91.6 21.9
450 -40.8 -8.7 31.6 6.7 1572.6 1.409 302.0 0.612 107.7 22.9
500 -57.1 -10.9 40.7 7.8 1444.3 1.294 254.7 0.712 125.3 23.9

 

[RKG]

I came up with -1.89 inches at 200 yards.

ICAO Standard Atmosphere
3200 fps
.120 G7 BC
2.6 inches sight height

B

My M4, sighted for 200 yards, shoots 1.5" high at 100 yards, using my load of 26.0 gr. 748 pushing a Win 55-gr. FMJBT at about 2750 fps.

 

[Bob P]

My M4, sighted for 200 yards, shoots 1.5" high at 100 yards, using my load of 26.0 gr. 748 pushing a Win 55-gr. FMJBT at about 2750 fps.

Right, but the OP is zeroed at 100 which is approx the peak of the arch so at 200 the bullet is starting to drop slightly.

 

[cockpitbob]

For most centerfire guns, one handy trick is that the 25yrd zero is very close to the 200yrd zero. It's on it's way up at 25 and going down at 200. I've seen a lot of guys zero at 25 and be on paper at 200.

 

[Jasper]

For most centerfire guns, one handy trick is that the 25yrd zero is very close to the 200yrd zero. It's on it's way up at 25 and going down at 200. I've seen a lot of guys zero at 25 and be on paper at 200.

on paper yes, but low.

a 50yd zero will be damned near POA @ 200yds (and ~ 2" high @ 100yds)

 

[flintoid]

if any of you guys have android phones, try out the app "shooter."

it'll answer these questions for you. I can't recommend it enough.

free "lite" version:

and here's a description: http://bulletin.accurateshooter.com/2010/03/new-ballistics-app-for-android-os-smart-phones/