Anyone care to crunch some numbers for me?

fuzzynuts54

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Well the breakdown is this.. My chrono was acting up the other day while working through some new loads for my .300win mag. I'm zeroed at 200y with 150gr smk hpbt at 3300fps, and the load I'm going to fine tune is 208gr a-max's hitting about 2.7" low while using the same point of aim.

The software on my iPhone won't alow me to determine the velocity and the zero of the a-max load. This is just for curiousity sake until I can get out again. My halfwitted estimate is 2900fps.
Or for someone with a load data program...
77gr of h1000, Winchester brass, cci magnum primers (250's I think), .308 cal 208gr a-max, 3.5" col, 24" barrel.
 
Running it through QuickTarget
Tabular trajectory data at Std.ICAO Atmosphere
-------------------------------------------------------------------------------------
Gun / Ammunition : .300 Win. Mag.(W)
Bullet : .308, 208, Hornady A-MAX 30712
Bullet weight : 208 grains or 13.48 Grams
Muzzle velocity : 2713 fps
Crosswind speed : 1 Mph
Ballistic Coefficient(s) (G1):
C1=0.648@V>0 fps;


Optimum trajectory information :
Optimum sight-in range (X) = 195 Yds.
with max. ordinate above LOS at range (M)= 118 Yds.
and max. point blank range (P)= 225 Yds.
-------------------------------------------------------------------------------------
Sight-in clicks, 1 click = 1.0 cm/100 m or 0.394 in/100 m
Height of sight above bore axis = 5.0 cm or 1.969 inch
Gun is zeroed-in at 200 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 1.0 Mph zero range 33 fps
-------------------------------------------------------------------------------------
·Yards fps s ft.lbs. in. in. MOA in. Clicks MOA yds ·
-------------------------------------------------------------------------------------
| 0 2713 0.0000 3399 -2.0 0.0 ----- 0.0 ------ ----- 0.00
| 50 2643 0.0562 3227 +0.4 0.0 0.00 0.6 -2.4 -0.84 0.62
| 100 2575 0.1138 3062 +1.6 0.0 0.00 2.5 -4.4 -1.53 1.24
M 120 2547 0.1372 2997 +1.7 0.0 0.00 3.6 -3.9 -1.36 1.50
| 150 2507 0.1726 2903 +1.5 0.0 0.00 5.6 -2.7 -0.93 1.89
X 200 2440 0.2326 2751 0.0 0.0 0.00 10.1 0.0 0.00 2.54
P 229 2402 0.2684 2665 -1.5 0.0 0.00 13.4 +1.8 +0.64 2.93
| 250 2375 0.2947 2605 -2.9 0.0 0.00 16.0 +3.3 +1.13 3.22
| 300 2310 0.3589 2465 -7.5 0.0 0.00 23.6 +6.9 +2.38 3.92
| 350 2247 0.4250 2332 -13.7 0.0 0.00 32.8 +10.8 +3.73 4.65
| 400 2184 0.4931 2204 -21.6 0.0 0.00 43.7 +15.0 +5.15 5.39
| 450 2123 0.5629 2081 -31.3 0.0 0.00 56.4 +19.3 +6.64 6.16
| 500 2062 0.6344 1964 -42.9 0.0 0.00 71.0 +23.8 +8.19 6.94
| 550 2002 0.7076 1852 -56.4 0.0 0.01 87.6 +28.5 +9.79 7.74
| 600 1943 0.7822 1744 -71.8 0.0 0.01 106.0 +33.2 +11.43 8.55
| 650 1886 0.8602 1642 -89.8 0.0 0.01 127.0 +38.4 +13.19 9.41
| 700 1829 0.9414 1545 -110.5 0.1 0.01 150.7 +43.8 +15.07 10.30
| 750 1774 1.0256 1454 -133.9 0.1 0.01 177.1 +49.6 +17.05 11.22
| 800 1721 1.1126 1368 -160.3 0.1 0.01 206.5 +55.7 +19.13 12.17
| 850 1668 1.2022 1286 -189.6 0.1 0.01 238.9 +62.0 +21.30 13.15
| 900 1617 1.2941 1208 -222.0 0.1 0.01 274.2 +68.5 +23.55 14.15
| 950 1567 1.3883 1134 -257.4 0.1 0.01 312.7 +75.3 +25.88 15.18
| 1000 1518 1.4846 1065 -296.0 0.1 0.01 354.3 +82.2 +28.26 16.24
-------------------------------------------------------------------------------------
M = Peak vs. L.O.S, X = Set Zero, P = Max. Point Blank Range
Elevation above Angle of Site (0.0 deg.) = 0.0959 deg.
 
Thank you very much. If I'm reading that right the zero is 118y and velocity is 2713fps?
That's close enough for me at the moment. Oddly, that velocity is coming in substatially lower than all the data I've collected from reading forums.... Many of those embellished I suppose. Thank you again.
 
Quickload yields 2,713 at 49,529 psi for those components.

Oehler Ballistic Explorer reflects a 135 yard zero with this load to hit at -2.7" @ 200 yards.

What is your sight height above your bore centre?

What altitude is your range?

Temperature

Wind direction & Speed?

Humidity?

Barometric pressure?

How detailed do you want to get?
 
Ya I wasn't thinking too clearly when I posted that. Elevation 300ft, temp 34*f, humidity and pressure ??, scope height 1.86", no wind worth mentioning.

I entered all the specifics in on the online jbm program for the 150gr smk loadout that's zeroed at 200y, and confirmed it's zero that day at the range. It gave me the barrels elevation of 4.24moa. Then i switched over to the 208amax with the same barrel elevation, it computed 2753fps, and a zero of 125yards.

I do have a chrono, I will be waiting for a sunnier day to do more testing. I have loaded up a bunch of bullets ranging from 76-79.5 gr and this time with equal weight brass. I found up to 13 grains variance from lightest to max in my lot.

I'm pretty excited to see the results. 77gr gave me 7/8"@200y, 76--bout 1-1/4, 78 had 2 touching but one bullet hit 1-1/4 high, 79 was also about 1-1/4.

I'm hoping consistent brass weights, case volume and the right load close these up tighter as they should. Then I can stop fiddling and just shoot finally.
 
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