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 Ballistic data / Check my homework?
gunshinestate  [Member]
2/26/2010 4:09:06 PM
Im in the process of learning ballistics data and such and have been working with JBM calculations.

Would any of you mind taking a look at this and tell me if you see any glaring faults with my input data?

Going to the range soon and want to have a good starting point.

ETA RIFLE INFO.

.223 Ar.
16" WOA SS barrel
Burris PEPR mount
SS 3-9x40 (c.o.b. ~2.5 ?????)





From JBM __
Trajectory
Input Data
Manufacturer: Nosler Description: Partition™ Spitzer
Caliber: 0.224 in Weight: 60.0 gr
Ballistic Coefficient: 0.228 G1
Bullet Length (Library): 0.790 in
Muzzle Velocity: 3140.0 ft/s Distance to Chronograph: 10.0 ft
Sight Height: 2.50 in Sight Offset: 0.00 in
Zero Height: 0.00 in Zero Offset: 0.00 in
Windage: 0.000 MOA Elevation: 0.000 MOA
Line Of Sight Angle: 0.0 deg Cant Angle: 0.0 deg
Barrel Twist: 7.0 in Twist Direction: Right
Wind Speed: 1.0 mph Wind Angle: 90.0 deg
Target Speed: 10.0 mph Target Angle: 90.0 deg
Temperature: 65.0 °F Pressure: 29.92 in Hg
Humidity: 0.0 % Altitude: 0.0 ft
Vital Zone Radius: 5.0 in
Std. Atmosphere at Altitude: No Pressure is Corrected: Yes
Zero at Max. Point Blank Range: No Target Relative Drops: Yes
Mark Sound Barrier Crossing: No Include Extra Rows: No
Column 1 Units: 1.00 mil Column 2 Units: 1.00 MOA
Round Output to Whole Numbers: No
Output Data
Elevation: 5.649 MOA Windage: -0.105 MOA
Atmospheric Density: 0.07560 lb/ft³ Speed of Sound: 1122.9 ft/s
Maximum PBR: 342 yd Maximum PBR Zero: 296 yd
Range of Maximum Height: 174 yd Energy at Maximum PBR: 456.7 ft•lbs
Sectional Density: 0.171 lb/in² Stability at Muzzle: 3.637
"</> </>
Calculated Table
0 drop mil drop moa wind mil wind moa 3154.8 2.809 1325.8 0.000 *** ***
50 0.0 0.0 0.0 0.0 2937.6 2.616 1149.5 0.049 4.8 16.6
100 0.4 1.4 0.0 0.1 2730.8 2.432 993.4 0.102 5.0 17.2
150 0.3 1.2 0.1 0.2 2533.3 2.256 854.9 0.159 5.2 17.8
200 0.1 0.4 0.1 0.3 2344.2 2.088 732.0 0.221 5.4 18.6
250 -0.2 -0.7 0.1 0.5 2163.2 1.926 623.3 0.287 5.6 19.3
300 -0.6 -2.0 0.2 0.6 1990.3 1.772 527.6 0.360 5.9 20.2
350 -1.0 -3.5 0.2 0.8 1826.1 1.626 444.2 0.438 6.1 21.1
400 -1.5 -5.3 0.3 0.9 1671.6 1.489 372.2 0.524 6.4 22.0
450 -2.1 -7.4 0.3 1.1 1528.2 1.361 311.1 0.618 6.7 23.1
500 -2.8 -9.7 0.4 1.4 1397.8 1.245 260.3 0.721 7.0 24.2
550 -3.6 -12.4 0.5 1.6 1282.5 1.142 219.1 0.833 7.4 25.5
600 -4.5 -15.5 0.5 1.9 1184.9 1.055 187.0 0.955 7.8 26.7
26/02/10 16:06, JBM/jbmtraj_drift-5.0.cgi


gunshinestate  [Member]
3/3/2010 11:16:26 AM
Anyone?
bigmill51  [Member]
3/3/2010 11:20:02 AM
Ive used JMB recently. The input looks good.
gunshinestate  [Member]
3/3/2010 2:14:15 PM
thanks bigmil.


It is my first time messing around with it and im going on a hunting trip with my new build.

I want to at least make sure im in the ballpark with the figures before I send $'s down range.


Have a good one.


fx.
NOMADSS  [Member]
3/28/2010 2:58:25 PM
The data should be real close just make sure your record and track your real world data.

NOMAD
8541 3/6,STA 3/2 STA,
Fast CO.,MCSFTCO CQB Section
Hurdle the dead, and Trample the weak!
NRA LIFE MEMBER


DansFlash  [Team Member]
6/6/2010 7:58:04 AM
This thread just reminded me to buy some round count books.
Maryland_Shooter  [Team Member]
7/21/2010 7:07:39 AM
Originally Posted By DansFlash:
This thread just reminded me to buy some round count books.


Can you explain why these are handy?

Thanks in advance