Hi Mike,
Ballistic calculators allow one to do two primary functions. (1) Figure out long range ballistics at distances well beyond the Rifleman's Quarter Mile, and (2) get a rough idea of the come-ups needed for various fixed distances with your particular rifle, depending on sight offset from bore, muzzle velocity, and bullet type.
In the first case, when shooting well past traditional quarter mile ranges using rifles, ballistic calculators allow one to understand what scope bases are needed. Do you need a 15, 20, 30 MOA base, or something entirely different, for use with your intended scope? You only get about 70 MOA total adjustment range with many scopes. Only about half that is available if using a 0 MOA base. If you are wanting to shoot out to 1,000 yards, for example, you need anywhere from 35 to 50 MOA total come-up, depending on your cartridge and rifle. If your scope can just get there, at the very upper limits of its come-up range, you now have no windage capability left available, due to the mechanical scope tube limits. Put in the appropriate scope base, though, say 20 MOA, thereby permitting using both ends of the scope's elevation adjustment range, and you now do have significant windage adjustment capability out at distance. Your mechanical elevation and windage is now not max'ed out. With a 10 mph full value cross wind at 1000 yards, you need anywhere from about 6 MOA to 10+ MOA of windage, depending on your rifle's and its bullet's characteristics. If your scope is maxed out getting to 1000 yards, you only have KY windage available. A ballistics calculator becomes very nice to have, when building up a rifle, to avoid making expensive mistakes.
In the second case, when shooting expensive cartridges at longer ranges, a ballistic calculator is a definite money saver, too.
At distances out to only 400 yards, or even to 600 yards, a ballistics calculator is often not needed. Except when shooting expensive ammo in a rifle suitable for reaching out to distances from 1200 to 2400 yards, and simply getting DOPE (data on previous engagements, data on personal equipment) at the shorter ranges out to 400 to 600 yards. Then, the ballistics calculator becomes very worthwhile.
Appleseed is traditionally a shoot what you bring event. Not everyone shoots a service rifle, solely. Diversity in rifles is a good thing! It makes one think, at the very least.
--gb
