I'm fairly new to hunting and muzzleloading and I never gave much thought to ballistics before. You'd buy a shotgun or ML, choose a load based on biases or superstition, sight in with that load, and then never change anything.
Now, with more time to spare, it's apparent that I'm woefully ignorant on the subject of ballistics. Let me see if this is how it goes:
So you have to choose a bullet size, weight, caliber, etc. I chose Hornady .430 300gr XTP/HP. You can use Hornady's website to get the Ballistics Coefficient (B/C) of .245 and Sectional Density of .232.
Using the manufacturer's manual, choose a suggested powder load. I used 45gr of IMR-4227. The manual will give you muzzle velocity (2166fps) and energy (3120fps) for that bullet and powder.
So then you need to find a Bullet Drop Calculator - I used the one at
www.sav10ml.com. Entering bullet weight, B/C, muzzle velocity and some other factors the BDC will compute the bullet drop at various distances. Say the drop is 0" at 100yds, 3" at 150yds, 9" at 200 yds, 18" at 250 yds. If you the re-sight 3" high at 100yds, you'd be dead on at 150yds, low 5" at 200yds, low 15" at 250yds.
So your effective range is about 200 yards because of the difficulty of aiming at at deer and holding 15" high. And you have to validate all the figures at the range.
So my questions are:
Is this method correct?
How much do the other factors in the BDC (like Altitude, Relative Humidity, Barometric Pressure, Air Density, etc) change the results?
What is B/C? Is a higher number 'better'?
How do you decide to trade a 300gr bullet with more energy for a 240gr bullet with more velocity? In the case above, using a Hornady 240gr XTP/HP doesn't affect the drop much - the difference is only .1" at 150yds, .2" at 200yds, .1" at 250yds. Why shoot a 240gr, which everybody seems to favor ?
