We just had a lenthy discussion on another board about this...This straightened me right out Karsten,
Let me see if I can do this in a semi clear manner, using generalities.
You seem to be thinking in inches of elevation, and probably "clicks" on the scope. Many shooters inexperienced (NO FLAME) in long range shooting do this.
Competition and long range shooters think in MOA, as you've observed, and it can be confusing trying to do the mental gymnastics. An inch is an inch no matter what distance, and an MOA is sorta variable.
MOA roughly equals 1 inch X Distance in yards
1 MOA at 100 yards = 1 inch
1 MOA at 500 yards = 5 inches
1 MOA at 1000 yards= 10 inches.
So when I said 30.5 MOA I actually allowed for 305 inches of elevation change at 1000 yards.
By doing the mental math in MOA a shooter can quickly dial in adjustments to his/her scope to take a shot.
So my 30.5 MOA would be two complete revolutions on the scope as opposed to counting 122 clicks and missing one or two of them in the process. It's just a faster measurement mentally and physically. Those indexed target turrets really help in doing this quickly.
Also helpful is getting away from the mindset of "where does it shoot if I'm at XXX at 100 yards". What needs to happen is that you have your 100 yard zero. To shoot 200 yards you learn via ballistics program(approximate)
or by actually shooting the data (accurate), how many MOA to dial into the elevation setting on your scope.
This is done for each range you would expect to shoot. Most of us have data every 100 yards to 1000 yards. Some of us have it in 25 yard increments all the way back to 1000 yards. Depending on what you are going to do, the data becomes valuable.
Since you're playing with the JBM program, you probably noticed that things like elevation above sea level, temp, barometric pressure all have effect on bullet flight.
Alot of us shoot data for each of the seasons, and travel to different ranges in the country to shoot at various altitudes, temps, atmospheric densities.
As Boltripper (who BTW is a very good rifleman) noted, alot of us compete and attend classes. It's just more data for the log book.
Also remember that most longrange shooters handload for their rifles. Using factory data gives less than impressive results on the ballistics comp. Using actual data shot over a chronograph gives much more impressive numbers in alot of instances.
On the subject of 1200 yard shots, yes the bullet does come down at a steep angle past 1000 yards. From shooting on the tank trails at Ft Hood I can tell you that by 1400 yards the 308 is pretty well over and done with for reliable first round target strike. Some of the delta guys I've seen can make it look good......I sure can't.
Hope all this rambling made some sense of things. Best to all.
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Hope that helped.
Karsten
, Art
