Cameron SS
CGN Ultra frequent flyer
- Location
- Ground Zero
So you asked a bunch of questions.
FIrst you need to know the value of the hash marks on your scope. Are they MOA or MIL-dot. What are the increments?
Then you want to know if your scope is first focal plane, or second. IF second, which is the most common, then the value of those increments will change if you change the power setting on your scope.
The bullet drop for your rounds will depend on the ammo. There are two good ways to figure out how much a particular ammo will drop, but good shooters will do both.
FIrst is use a ballistic calculator to get a bullet drop chart which would PREDICT how much drop you would have at each distance. Chronographing your rounds and knowing the actual muzzle velocity of your rounds will make a much more reliable result. Never rely on manufacturers stated claims of velocity as your gun could vary significantly from their test gun.
Second is to ACTUALLY shoot at each distance, uncorrected, and measure the drop yourself. This will depend entirely on how good your range or target spot is.
Getting an ethical kill is a function of shot placement, and bullet construction. For me, I would never take a shot in the field that I had never taken on the range at least a hundred times.
I shoot about five hundred rounds a year at distances from 100,150,200,250,300, and know the exact corrections required to hold a sub MOA hit at any of those distances. I would never hesitate to take a 300 m shot in the field, cause I KNOW I can hit it. From year to year I may fire an addition zero to 500 rounds at distances from 400-1000m. In a year where I was doing a lot of longer distance shooting, and doing it well, I would be far more comfortable taking those shots in the field. Last year however, was the year of the pistol for me and I didn't get anything much past 300 in at all, so would have been very hesitant to shoot at much past 400. I have been accused of being overcautious, but to each their own.
One method that is common used to ensure accurate throughout your comfort zone range, is called the maximum point blank range method.
http://www.chuckhawks.com/mpbr_hunting.htm
Basically, your bullet follows an arc, up and down. If you define a target area, like the vitals of your intended prey, or an average of multiple species, you can use a ballistic calculator to determine A) what the maximum range you can shoot at while the bullet will always be in that target area, and B) what distance you need to zero your rifle at to achieve that maximum distance.
If my zero my 300 wsm for 276 meters (I just do 275), I can shoot targets out to 354 meters (I use 350) and without making any corrections, the bullet will never be more than 3 inches high or low from my point of aim. I think a lot of guys use some version of this method. The most important thing when using this method, to me, is to be able to actually zero at that range, and not just zero at 200 and guess what a 275 meter zero would be, and then to actually shoot at all of the possible ranges you could encounter an animal, and confirm the math.
