Re: 30-06 ammo for LR
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: flounderpounder</div><div class="ubbcode-body">Physics and gravity....they're a bitch! How can an object weighing 30grains more, travel the same distance and end up going faster than it's lighter partner, who started traveling faster to begin with? Thanks MM, that's what I suspected, just don't understand how. </div></div>
Basically, The 208 (BC .648) is more aerodynamic. It has less drag, a lot less drag, so it retains velocity better.
The 178 (BC .495) starts faster but loses velocity faster (more drag). In this comparison, just past 600 yards, the 208 is going faster than the 178. The 178 drops below 1200 fps around 1400 yards, while the 208 retains 1200 fps past 1600 yards.
178 AMax, 2900 fps MV (4000' el):
<div class="ubbcode-block"><div class="ubbcode-header">Code:</div><div class="ubbcode-body ubbcode-pre" ><pre>
Bullet : .308, 178, Hornady A-MAX 30712
Muzzle velocity : 2900 fps
Crosswind speed : 10 Mph
Ballistic Coefficient(s) (G1):
C1=0.495@V>0 fps;
-------------------------------------------------------------------------------------
Sight-in clicks, 1 click = 0.915 cm/100 yd. or 0.36 in/100 yd.
Height of sight above bore axis = 5.0 cm or 1.969 inch
Gun is zeroed-in at 100 yds,
by sighting-in at level firing
-------------------------------------------------------------------------------------
Range Velo Time of Energy Path Deflection Total Sight correction Target
city flight to at crosswind drop for setting new lead
LOS of 10.0 Mph zero range 33 fps
-------------------------------------------------------------------------------------
·Yards fps s ft.lbs. in. in. MOA in. Clicks MOA yds ·
-------------------------------------------------------------------------------------
| 0 2900 0.0000 3324 -2.0 0.0 ----- 0.0 ------ ----- 0.00
X 100 2743 0.1069 2972 0.0 0.6 0.57 2.2 0.0 0.00 1.17
| 200 2590 0.2197 2652 -2.7 2.3 1.07 9.0 +3.7 +1.28 2.40
| 300 2443 0.3380 2359 -10.4 4.9 1.55 20.8 +9.6 +3.32 3.70
| 400 2301 0.4648 2092 -24.1 9.0 2.14 38.7 +16.7 +5.75 5.08
| 500 2163 0.5998 1849 -44.4 14.5 2.78 63.1 +24.7 +8.49 6.56
| 600 2030 0.7424 1629 -72.0 21.4 3.41 94.8 +33.3 +11.45 8.12
| 700 1901 0.8933 1429 -107.5 29.8 4.06 134.5 +42.6 +14.67 9.77
| 800 1780 1.0579 1251 -153.8 40.5 4.84 184.9 +53.4 +18.36 11.57
| 900 1664 1.2343 1094 -211.5 53.4 5.66 246.7 +65.2 +22.44 13.50
| 1000 1553 1.4208 954 -281.1 68.0 6.49 320.4 +78.0 +26.84 15.54
| 1100 1450 1.6187 831 -364.5 84.6 7.34 407.9 +92.0 +31.64 17.70
| 1200 1357 1.8335 728 -466.4 104.2 8.29 514.0 +107.9 +37.11 20.05
| 1300 1272 2.0616 639 -587.1 126.1 9.27 638.9 +125.4 +43.12 22.55
| 1400 1198 2.3049 567 -730.6 150.8 10.28 786.5 +144.9 +49.83 25.21
| 1500 1136 2.5622 510 -899.0 177.8 11.32 959.0 +166.4 +57.22 28.02
| 1600 1084 2.8328 464 -1095.0 207.3 12.37 1159.2 +190.0 +65.35 30.98
</pre></div></div>
208 AMax, 2700 fps MV (4000' el),
<div class="ubbcode-block"><div class="ubbcode-header">Code:</div><div class="ubbcode-body ubbcode-pre" ><pre>
Bullet : .308, 208, Hornady A-MAX 30712
Bullet weight : 208 grains or 13.48 Grams
Muzzle velocity : 2700 fps
Crosswind speed : 10 Mph
Ballistic Coefficient(s) (G1):
C1=0.648@V>0 fps;
-------------------------------------------------------------------------------------
Range Velo Time of Energy Path Deflection Total Sight correction Target
city flight to at crosswind drop for setting new lead
LOS of 10.0 Mph zero range 33 fps
-------------------------------------------------------------------------------------
·Yards fps s ft.lbs. in. in. MOA in. Clicks MOA yds ·
-------------------------------------------------------------------------------------
| 0 2700 0.0000 3367 -2.0 0.0 ----- 0.0 ------ ----- 0.00
M 89 2597 0.1010 3115 0.0 0.4 0.40 1.9 -0.1 -0.03 1.10
X 100 2584 0.1137 3085 0.0 0.5 0.44 2.5 0.0 0.00 1.24
P 197 2475 0.2278 2829 -3.0 1.6 0.76 9.7 +4.2 +1.44 2.49
| 200 2472 0.2314 2821 -3.2 1.6 0.77 10.0 +4.4 +1.50 2.53
| 300 2362 0.3554 2576 -12.0 3.9 1.23 23.3 +11.1 +3.82 3.89
| 400 2255 0.4859 2348 -27.2 7.3 1.74 43.0 +18.9 +6.50 5.31
| 500 2150 0.6227 2136 -49.3 11.8 2.26 69.5 +27.4 +9.41 6.81
| 600 2049 0.7651 1938 -78.7 17.3 2.76 103.3 +36.4 +12.52 8.37
| 700 1950 0.9128 1755 -115.7 23.8 3.24 144.7 +45.9 +15.78 9.98
| 800 1854 1.0709 1587 -162.6 32.0 3.82 196.0 +56.4 +19.41 11.71
| 900 1762 1.2389 1434 -220.4 42.0 4.46 258.3 +68.0 +23.38 13.55
| 1000 1674 1.4156 1294 -289.7 53.6 5.12 332.0 +80.4 +27.66 15.48
| 1100 1589 1.6001 1166 -370.9 66.5 5.77 417.6 +93.6 +32.20 17.50
| 1200 1507 1.7918 1049 -464.5 80.7 6.42 515.7 +107.5 +36.97 19.60
| 1300 1430 1.9952 945 -574.3 96.9 7.12 629.9 +122.6 +42.19 21.82
| 1400 1360 2.2115 854 -702.9 115.4 7.87 763.0 +139.4 +47.94 24.18
| 1500 1294 2.4378 773 -850.2 135.7 8.64 914.6 +157.3 +54.12 26.66
| 1600 1234 2.6747 703 -1018.1 157.9 9.42 1087.0 +176.6 +60.76 29.25
</pre></div></div>