Rough .308 Ballistics...? 16 inch vs. 24?

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[ARCHIVED THREAD] - Rough .308 Ballistics...? 16 inch vs. 24?

Posted: 6/25/2006 8:37:23 PM EDT

Ballistic tables? 16 inch vs. 24?

Thanks!

Posted: 6/25/2006 9:02:22 PM EDT

[#1]

Tagaroo and a bumpy too.

Posted: 6/27/2006 12:54:46 AM EDT

[#2]

Here are tables for 24" and 16" 308 barrels:

-------------------------------------------------------------------------------------
 Gun / Ammunition : .308 Win.
 Bullet           : .308, 168, Sierra HPBT MK 2200
 Bullet weight    : 168 grains
 Muzzle velocity  : 2739 fps
 Crosswind speed  : 10 Mph 

 Table of Various Zero Ranges - Trajectory Path to LOS in inches
-------------------------------------------------------------------------------------------------------------
 Range               50 yd.  100 yd.  150 yd.  200 yd.  250 yd.  300 yd.  350 yd.  400 yd.  450 yd.  500 yd. 
-------------------------------------------------------------------------------------------------------------
  50 yd. Zero           X       +0.7     +0.1     -1.9     -5.6    -11.0    -18.3    -27.4    -38.7    -52.8   
 100 yd. Zero          -0.4      X       -1.0     -3.4     -7.4    -13.2    -20.8    -30.3    -42.0    -56.4   
 150 yd. Zero           0.0     +0.6      X       -2.1     -5.8    -11.3    -18.6    -27.7    -39.1    -53.3   
 200 yd. Zero          +0.5     +1.7     +1.6      X       -3.2     -8.1    -14.9    -23.5    -34.4    -48.0   
 250 yd. Zero          +1.1     +3.0     +3.5     +2.6      X       -4.3    -10.4    -18.4    -28.6    -41.6   
 300 yd. Zero          +1.8     +4.4     +5.6     +5.4     +3.6      X       -5.4    -12.7    -22.2    -34.4   
 350 yd. Zero          +2.6     +5.9     +8.0     +8.5     +7.4     +4.6      X       -6.5    -15.2    -26.7   
 400 yd. Zero          +3.4     +7.6    +10.4    +11.8    +11.5     +9.5     +5.7      X       -7.9    -18.6   
 450 yd. Zero          +4.3     +9.3    +13.0    +15.3    +15.9    +14.8    +11.9     +7.1      X       -9.8   
 500 yd. Zero          +5.3    +11.3    +16.0    +19.2    +20.8    +20.7    +18.7    +14.9     +8.8      X     
-------------------------------------------------------------------------------------------------------------
 192 yd. PB Zero       +0.4     +1.5     +1.3     -0.4     -3.7     -8.7    -15.5    -24.3    -35.2    -48.9   
-------------------------------------------------------------------------------------------------------------
Velocity       fps.  2639.1   2539.6   2440.9   2344.4   2250.2   2158.1   2066.4   1973.9   1883.2   1796.3   
Energy      ft.lbs.  2597.9   2405.6   2222.2   2050.0   1888.5   1737.2   1592.7   1453.2   1322.8   1203.5   
Deflection      in.     0.2      0.8      1.6      3.0      4.9      7.3     10.2     13.4     17.4     22.2   
Correction  MOA/mph   0.043    0.074    0.105    0.144    0.188    0.233    0.277    0.321    0.369    0.424   
Time            sec   0.056    0.114    0.174    0.236    0.302    0.370    0.441    0.514    0.592    0.674   


-------------------------------------------------------------------------------------
 Gun / Ammunition : .308 Win.
 Bullet           : .308, 168, Sierra HPBT MK 2200
 Bullet weight    : 168 grains
 Muzzle velocity  : 2507 fps
 Crosswind speed  : 10 Mph 

 Table of Various Zero Ranges - Trajectory Path to LOS in inches
-------------------------------------------------------------------------------------------------------------
 Range               50 yd.  100 yd.  150 yd.  200 yd.  250 yd.  300 yd.  350 yd.  400 yd.  450 yd.  500 yd. 
-------------------------------------------------------------------------------------------------------------
  50 yd. Zero           X       +0.5     -0.7     -3.7     -8.5    -15.2    -24.4    -36.4    -51.2    -69.0   
 100 yd. Zero          -0.2      X       -1.4     -4.6     -9.6    -16.6    -26.1    -38.2    -53.3    -71.3   
 150 yd. Zero          +0.2     +0.9      X       -2.7     -7.3    -13.8    -22.8    -34.5    -49.0    -66.6   
 200 yd. Zero          +0.9     +2.3     +2.0      X       -3.9     -9.8    -18.0    -29.0    -42.9    -59.9   
 250 yd. Zero          +1.7     +3.9     +4.4     +3.1      X       -5.1    -12.6    -22.8    -35.9    -52.1   
 300 yd. Zero          +2.5     +5.5     +6.9     +6.5     +4.2      X       -6.7    -16.0    -28.3    -43.6   
 350 yd. Zero          +3.5     +7.4     +9.8    +10.3     +9.0     +5.7      X       -8.4    -19.8    -34.1   
 400 yd. Zero          +4.5     +9.6    +12.9    +14.5    +14.2    +12.0     +7.4      X      -10.3    -23.6   
 450 yd. Zero          +5.7    +11.8    +16.3    +19.1    +20.0    +18.9    +15.4     +9.1      X      -12.1   
 500 yd. Zero          +6.9    +14.3    +20.0    +23.9    +26.0    +26.2    +23.9    +18.8    +10.9      X     
-------------------------------------------------------------------------------------------------------------
 174 yd. PB Zero       +0.5     +1.6     +0.9     -1.5     -5.8    -12.0    -20.6    -32.0    -46.3    -63.6   
-------------------------------------------------------------------------------------------------------------
Velocity       fps.  2408.8   2313.1   2219.6   2128.2   2035.6   1943.6   1854.4   1768.7   1686.2   1606.5   
Energy      ft.lbs.  2164.3   1995.7   1837.6   1689.4   1545.5   1409.1   1282.6   1166.8   1060.5    962.6   
Deflection      in.     0.1      0.8      2.0      3.6      5.7      8.2     11.6     15.8     20.8     26.4   
Correction  MOA/mph   0.022    0.074    0.124    0.172    0.218    0.263    0.317    0.377    0.440    0.504   
Time            sec   0.060    0.124    0.191    0.260    0.332    0.406    0.485    0.568    0.656    0.748

Posted: 6/27/2006 1:07:40 AM EDT

[#3]

Just keeping my eyes from hurting....Tanks for the info, I was curious myself.

Quoted:
Here are tables for 24" and 16" 308 barrels:

-------------------------------------------------------------------------------------
Gun / Ammunition : .308 Win.
Bullet : .308, 168, Sierra HPBT MK 2200
Bullet weight : 168 grains
Muzzle velocity : 2739 fps
Crosswind speed : 10 Mph

Table of Various Zero Ranges - Trajectory Path to LOS in inches
-------------------------------------------------------------------------------------------------------------
Range 50 yd. 100 yd. 150 yd. 200 yd. 250 yd. 300 yd. 350 yd. 400 yd. 450 yd. 500 yd.
-------------------------------------------------------------------------------------------------------------
50 yd. Zero X +0.7 +0.1 -1.9 -5.6 -11.0 -18.3 -27.4 -38.7 -52.8
100 yd. Zero -0.4 X -1.0 -3.4 -7.4 -13.2 -20.8 -30.3 -42.0 -56.4
150 yd. Zero 0.0 +0.6 X -2.1 -5.8 -11.3 -18.6 -27.7 -39.1 -53.3
200 yd. Zero +0.5 +1.7 +1.6 X -3.2 -8.1 -14.9 -23.5 -34.4 -48.0
250 yd. Zero +1.1 +3.0 +3.5 +2.6 X -4.3 -10.4 -18.4 -28.6 -41.6
300 yd. Zero +1.8 +4.4 +5.6 +5.4 +3.6 X -5.4 -12.7 -22.2 -34.4
350 yd. Zero +2.6 +5.9 +8.0 +8.5 +7.4 +4.6 X -6.5 -15.2 -26.7
400 yd. Zero +3.4 +7.6 +10.4 +11.8 +11.5 +9.5 +5.7 X -7.9 -18.6
450 yd. Zero +4.3 +9.3 +13.0 +15.3 +15.9 +14.8 +11.9 +7.1 X -9.8
500 yd. Zero +5.3 +11.3 +16.0 +19.2 +20.8 +20.7 +18.7 +14.9 +8.8 X
-------------------------------------------------------------------------------------------------------------
192 yd. PB Zero +0.4 +1.5 +1.3 -0.4 -3.7 -8.7 -15.5 -24.3 -35.2 -48.9
-------------------------------------------------------------------------------------------------------------
Velocity fps. 2639.1 2539.6 2440.9 2344.4 2250.2 2158.1 2066.4 1973.9 1883.2 1796.3
Energy ft.lbs. 2597.9 2405.6 2222.2 2050.0 1888.5 1737.2 1592.7 1453.2 1322.8 1203.5
Deflection in. 0.2 0.8 1.6 3.0 4.9 7.3 10.2 13.4 17.4 22.2
Correction MOA/mph 0.043 0.074 0.105 0.144 0.188 0.233 0.277 0.321 0.369 0.424
Time sec 0.056 0.114 0.174 0.236 0.302 0.370 0.441 0.514 0.592 0.674

-------------------------------------------------------------------------------------
Gun / Ammunition : .308 Win.
Bullet : .308, 168, Sierra HPBT MK 2200
Bullet weight : 168 grains
Muzzle velocity : 2507 fps
Crosswind speed : 10 Mph

Table of Various Zero Ranges - Trajectory Path to LOS in inches
-------------------------------------------------------------------------------------------------------------
Range 50 yd. 100 yd. 150 yd. 200 yd. 250 yd. 300 yd. 350 yd. 400 yd. 450 yd. 500 yd.
-------------------------------------------------------------------------------------------------------------
50 yd. Zero X +0.5 -0.7 -3.7 -8.5 -15.2 -24.4 -36.4 -51.2 -69.0
100 yd. Zero -0.2 X -1.4 -4.6 -9.6 -16.6 -26.1 -38.2 -53.3 -71.3
150 yd. Zero +0.2 +0.9 X -2.7 -7.3 -13.8 -22.8 -34.5 -49.0 -66.6
200 yd. Zero +0.9 +2.3 +2.0 X -3.9 -9.8 -18.0 -29.0 -42.9 -59.9
250 yd. Zero +1.7 +3.9 +4.4 +3.1 X -5.1 -12.6 -22.8 -35.9 -52.1
300 yd. Zero +2.5 +5.5 +6.9 +6.5 +4.2 X -6.7 -16.0 -28.3 -43.6
350 yd. Zero +3.5 +7.4 +9.8 +10.3 +9.0 +5.7 X -8.4 -19.8 -34.1
400 yd. Zero +4.5 +9.6 +12.9 +14.5 +14.2 +12.0 +7.4 X -10.3 -23.6
450 yd. Zero +5.7 +11.8 +16.3 +19.1 +20.0 +18.9 +15.4 +9.1 X -12.1
500 yd. Zero +6.9 +14.3 +20.0 +23.9 +26.0 +26.2 +23.9 +18.8 +10.9 X
-------------------------------------------------------------------------------------------------------------
174 yd. PB Zero +0.5 +1.6 +0.9 -1.5 -5.8 -12.0 -20.6 -32.0 -46.3 -63.6
-------------------------------------------------------------------------------------------------------------
Velocity fps. 2408.8 2313.1 2219.6 2128.2 2035.6 1943.6 1854.4 1768.7 1686.2 1606.5
Energy ft.lbs. 2164.3 1995.7 1837.6 1689.4 1545.5 1409.1 1282.6 1166.8 1060.5 962.6
Deflection in. 0.1 0.8 2.0 3.6 5.7 8.2 11.6 15.8 20.8 26.4
Correction MOA/mph 0.022 0.074 0.124 0.172 0.218 0.263 0.317 0.377 0.440 0.504
Time sec 0.060 0.124 0.191 0.260 0.332 0.406 0.485 0.568 0.656 0.748

www.ar15barrels.com/gfx/308-16vs24.gif

looks like roughly a 200fps loss across the board..

Posted: 6/27/2006 2:35:07 AM EDT

[#4]

Thanks much for the info...200 fps, for eight more inches of barrel...roughly 25 fps per inch...hardly worth it unless going for the big distances I guess.

I'm sure the cutoff point though for full ballistics is +/- 20 inches for the .308.

Posted: 6/27/2006 9:04:52 AM EDT

[#5]

...And +/- 300 Ft. lbs. loss in energy across the board.

Posted: 6/29/2006 5:12:56 AM EDT

[#6]

Ouch...looks more like 400 lbs at 50-100 yards...

Just saw some ballistics where and 18 inch barrel gives 100 more feet per second.

Posted: 6/29/2006 2:24:45 PM EDT

[#7]

My 16" SR25 with BH 175BTHP was getting around 2400 FPS; 2353 at the low end, 2449 on the hight end. This was shot with a SWR Omega and are muzzle velocities.

Posted: 6/29/2006 4:32:56 PM EDT

[#8]

Where did you find those, GlockSlap?

Posted: 6/29/2006 4:57:40 PM EDT

[#9]

Quoted:
Just saw some ballistics where and 18 inch barrel gives 100 more feet per second.

Need to quote more info, such as bullet weight and pressure the loads run to...

I can load some 147gr bullets that will be WAY faster than the 168's in the charts above.
Of course it's not a fair comparison.

Also, it's not uncommon to see 50-100 fps variation between 2 barrels in the SAME CALIBER, using the SAME AMMO.

[ARCHIVED THREAD] - Rough .308 Ballistics...? 16 inch vs. 24?

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