ORIGINAL: andlan17
My buddy bought a browning A-bolt medallion in 270 WSM and the salesman told him to sight it in at 27 yards and it would be dead on at 200. does anyone know if this is true? he hasnt had a chance to shoot at that distance yet so i dont know if it is true. It it is true does anyone know it something like that would work for my 25-06?
This statement is based on a knowledge of a particular cartridge & load's trajectory curve. So, as mentioned above, it is THEORETICALLY CORRECT, and in addition, it DOES NOT take into consideration deflection (AKA windage) differences.
Over the years, I have THOROUGHLY tested this idea with a number of different rifles and cartridges. My findings arethat sighting in at ranges like 25-27 yards, etc., will usually get you "on paper" at 100 yards. But if you rely on a 27-yard zero to ensure that you are "dead on" at 200 (or any other) extended range, you are in for a serious disappointment! I have found that to make sure you are hitting where you want to hit at any of the extended ranges, it is ABSOLUTELY NECESSARY to shoot at those distances to MAKESURE of where your point of impact is out there. Additionally,I have found is that it is usual for the bullets to be off in deflection (windage) more often than in elevation.
So go ahead and zero at 27 yards to begin with. Then move to 200 and fire two or threerounds to actually see for yourself what reallyhappens with that particular rifle and load at 200 yards and beyond....