ORIGINAL: JagMagMan
ORIGINAL: Tuffbroadhead
Thats where I always zero my rifles in, my 308's are zeroed for 325 yards......
Point blank range is explained pretty simple as if a rifle was to be perfectly flat and shot, the bullet trajectory inclines(rises) slightly out of the muzzel and the point blank range is where the projectile crosses the line of the muzzel.
Wrong! First of all bullets do NOT rise!
Secondly, "Max Point Blank Range" for a given caliber and load "is the maximum range, at which the bullet is either higher, or lower than the line-of-sight, aiming point"
For example, if you use a 3" MPBR, and the MPBR is 325 yards, it means that if you aim "dead on" (line of sight,) your bullet will never be more than 3" higher, or 3" lower than theline of sightaiming point out to 325 yards.
Theoreticly, eleminating the need for "hold over" out to the max range!
Personally, my shots are hardly ever that long, so I usually sight in 0-1" high @ 100 yds. I don't like to hit 3" high on short range shots!
I just wanted to clarify what JagMagMan said about the bullet rise - since I was under the misunderstanding myself until someone explained it to me (at which point I said DUH!).
As he said, the bullet doesn't "rise" out of the muzzle. Bullets can only drop from the line of the barrel because of gravity. What you are doingis actually aiming the bullet up in the air a tiny bit. So in that sense, the trajectory does indeed goe up, then down from your line of sight, but does not rise from the line of the barrel.
This is what you do when you adjust your scope to hit zero at say 200 yards. To do that, you need to shoot upward a little so when it drops it hits zero at that point. The same reason why when you throw a ball, you loft it. Even a "fastball" has a tiny bit of loft out of the pitcher's hand.
Yourscope is aiming straight at the bullseye at 200, but the barrel itself is pointing slightly upward. The barrel and the scope are not pointing in exactly the same line. If your barrel was aiming straight at the target at 200 like the scope, the bullet would hit below zero because it drops.
In the arc the bullet makes, it will cross "zero" at two points, usually one pretty close in (e.g. 25to 50 yards) and one further out (e.g. 200 or 300 or something).Between the two zeros, it will hit targets at various places above zero. Beyond the far zero, it will continue downward, and begin to hit the target below the bullseye. Your "point blank" range is how far you can go out with acceptable bullet drop and still be in kill zone without making any aim compensation. For a deer, a 2-3 inch rise and drop is no problem. For a moose, you could probably be fine with twice that much.