# 6.5mm - 284 trajectory question ?



## 6162rk (Dec 5, 2004)

can anyone answer or do you have access to a computer program? 
i would like to know the amount of drop (inches of drop ) at 900 yards on the following assuming it is zeroed at 100 yards. thanks for your help.

caliber - 6.5mm - 284
.264 bullet diameter
139 grain lapua bullet
.615 ballistic coefficent
2,900 fps muzzle velocity


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## xdeano (Jan 14, 2005)

here you go, it might be a few inches off from your position, due to pressure, temp, etc.










xdeano


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## iwantabuggy (Feb 15, 2005)

Those number xdeano provided will be off a bit. You stated that the gun is zeroed at 100 yards and xdeano's numbers are for a trajectory that is -2.0 at 100 yards.

Trajectory Output 
Input Data 
Ballistic Coefficient: 0.615 G1 Bullet Weight: 139.00 gr 
Caliber: 0.264 in

Muzzle Velocity: 2900.0 ft/s Chronograph Distance: 10.0 ft

Sight Height: 1.50 in Sight Offset: 0.00 in 
Zero Height: 0.00 in Zero Offset: 0.00 in 
Azimuth: 0.00 MOA Elevation: 0.00 MOA 
LOS Angle: 0.0 deg Cant Angle: 0.0 deg

Wind Speed: 10.0 mph Wind Angle: 90.0 deg 
Target Speed: 10.0 mph Target Angle: 90.0 deg

Temperature: 59.0 °F Pressure: 29.92 in Hg 
Relative Humidity: 0.0 % Altitude: 0 ft

Vital Zone Radius: 5.0 in Std. Atmosphere at Altitude: No 
Corrected Pressure: Yes Target Relative Drops: Yes 
Zero at Max. Point Blank Range: No 
Calculated Parameters 
Elevation: 3.47 MOA Azimuth: 0.00 MOA

Atmospheric Density: 0.07647 lbs/ft³ Speed of Sound: 1116.5 ft/s

Maximum PBR: 360 yds Maximum PBR Zero: 305 yds 
Range at Max Height: 167 yds Energy at PBR: 1737.1 ft•lbs

Sectional Density: 0.285 lbs/in²

Calculated Table 
Range Drop Drop Windage Windage Velocity Mach Energy Time Lead Lead 
(yds) (in) (moa) (in) (moa) (ft/s) (none) (ft•lbs) (s) (in) (moa) 
0 -1.5 *** 0.0 *** 2905.2 2.602 2604.6 0.000 0.0 *** 
25 -0.7 -2.8 0.0 0.1 2866.1 2.567 2534.9 0.026 4.6 17.5 
50 -0.2 -0.4 0.1 0.2 2827.3 2.532 2466.7 0.052 9.2 17.6 
75 0.0 0.0 0.3 0.4 2788.8 2.498 2400.0 0.079 13.9 17.7 
100 -0.0 -0.0 0.5 0.5 2750.7 2.464 2334.9 0.106 18.7 17.8 
125 -0.3 -0.2 0.8 0.6 2712.9 2.430 2271.1 0.134 23.5 18.0 
150 -0.9 -0.6 1.1 0.7 2675.4 2.396 2208.8 0.161 28.4 18.1 
175 -1.9 -1.0 1.6 0.9 2638.2 2.363 2147.9 0.190 33.4 18.2 
200 -3.1 -1.5 2.1 1.0 2601.4 2.330 2088.3 0.218 38.4 18.3 
225 -4.7 -2.0 2.6 1.1 2564.8 2.297 2030.0 0.247 43.5 18.5 
250 -6.5 -2.5 3.3 1.3 2528.6 2.265 1973.1 0.277 48.7 18.6 
275 -8.8 -3.0 4.0 1.4 2492.6 2.233 1917.4 0.307 54.0 18.7 
300 -11.3 -3.6 4.8 1.5 2457.0 2.201 1862.9 0.337 59.3 18.9 
325 -14.3 -4.2 5.6 1.7 2421.6 2.169 1809.6 0.368 64.7 19.0 
350 -17.6 -4.8 6.6 1.8 2386.5 2.138 1757.6 0.399 70.2 19.2 
375 -21.3 -5.4 7.6 1.9 2351.7 2.106 1706.7 0.431 75.8 19.3 
400 -25.3 -6.0 8.7 2.1 2317.2 2.075 1656.9 0.463 81.4 19.4 
425 -29.8 -6.7 9.9 2.2 2283.0 2.045 1608.3 0.495 87.2 19.6 
450 -34.7 -7.4 11.2 2.4 2249.0 2.014 1560.8 0.528 93.0 19.7 
475 -40.1 -8.1 12.6 2.5 2215.3 1.984 1514.4 0.562 98.9 19.9 
500 -45.8 -8.8 14.0 2.7 2181.9 1.954 1469.1 0.596 104.9 20.0 
525 -52.1 -9.5 15.6 2.8 2148.8 1.925 1424.8 0.631 111.0 20.2 
550 -58.8 -10.2 17.2 3.0 2115.9 1.895 1381.6 0.666 117.2 20.3 
575 -65.9 -11.0 19.0 3.2 2083.4 1.866 1339.4 0.702 123.5 20.5 
600 -73.6 -11.7 20.8 3.3 2051.1 1.837 1298.2 0.738 129.9 20.7 
625 -81.8 -12.5 22.8 3.5 2019.1 1.808 1258.1 0.775 136.4 20.8 
650 -90.6 -13.3 24.8 3.6 1987.5 1.780 1218.9 0.812 143.0 21.0 
675 -99.8 -14.1 27.0 3.8 1956.1 1.752 1180.8 0.850 149.6 21.2 
700 -109.7 -15.0 29.2 4.0 1925.0 1.724 1143.6 0.889 156.4 21.3 
725 -120.1 -15.8 31.6 4.2 1894.3 1.697 1107.3 0.928 163.4 21.5 
750 -131.2 -16.7 34.1 4.3 1863.9 1.669 1072.0 0.968 170.4 21.7 
775 -142.8 -17.6 36.7 4.5 1833.8 1.642 1037.7 1.009 177.5 21.9 
800 -155.1 -18.5 39.4 4.7 1804.0 1.616 1004.3 1.050 184.8 22.1 
825 -168.1 -19.5 42.2 4.9 1774.6 1.589 971.8 1.092 192.2 22.2 
850 -181.8 -20.4 45.2 5.1 1745.5 1.563 940.2 1.134 199.7 22.4 
875 -196.2 -21.4 48.3 5.3 1716.8 1.538 909.5 1.178 207.3 22.6 
900 -211.3 -22.4 51.5 5.5 1688.4 1.512 879.7 1.222 215.0 22.8 
925 -227.2 -23.5 54.8 5.7 1660.5 1.487 850.8 1.267 222.9 23.0 
950 -243.9 -24.5 58.3 5.9 1632.9 1.463 822.8 1.312 230.9 23.2 
975 -261.3 -25.6 61.9 6.1 1605.7 1.438 795.7 1.359 239.1 23.4 
1000 -279.7 -26.7 65.7 6.3 1579.0 1.414 769.3 1.406 247.4 23.6

By my calculations you would be about -211.3 not -224.6.


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## xdeano (Jan 14, 2005)

I'm just going by the charts. If you could actually read the table of reference you may want to change your mind. This is a professional program, not just some hack that you got off the internet, with crazy numbers.

The numbers that i posted are for a 100yd zero. Follow the Bullet Path (inches) column, 100yds is 0.0 inches. Bullet Path (MOA) column is 0.0 inches. Meaning it's zeroed at 100yds. Crazy how that works.

Your 900yd drop is 194.64 inches, or 20.65 MOA if you're using comeups.

xdeano


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## 6162rk (Dec 5, 2004)

thank you for the information guys. it will be put to good use. much appreciated.


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## iwantabuggy (Feb 15, 2005)

xdeano said:


> I'm just going by the charts. If you could actually read the table of reference you may want to change your mind. This is a professional program, not just some hack that you got off the internet, with crazy numbers.
> 
> The numbers that i posted are for a 100yd zero. Follow the Bullet Path (inches) column, 100yds is 0.0 inches. Bullet Path (MOA) column is 0.0 inches. Meaning it's zeroed at 100yds. Crazy how that works.
> 
> ...


You are correct. I read it wrong. Funny how are numbers turned out so different. I wonder why. Probably due to assumptions that must be made since we don't have all the required information (elevation, barametrice pressure, sight height, etc.).


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## xdeano (Jan 14, 2005)

6162rk,
Do you own a 6.5-284 or just looking to buy? There are many cons against the 6.5-284, starting with barrel wear. There are other rounds that are much better on barrel wear but will serve the same purpose. 6.5-47Lapua, 260 Rem. etc.



> Funny how are numbers turned out so different. I wonder why. Probably due to assumptions that must be made since we don't have all the required information (elevation, barametrice pressure, sight height, etc.).


Yep, you're right about the assumptions that we had to make about all the above, it's funny how much such little things can change a bullets trajectory.

Even with this computer generate model we are both close, but still wrong, because every gun, bullet, powder charge, will vary as much as the nut behind the gun.

xdeano


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