Quote:
Originally Posted by LongDraw
Pick your flavor- If you are shooting a cartridge that is pushing a 130-180 grain bullet 2800-3200 fps and shooting inside of 500 yards cartridge selection is a moot point. Picking a proper bullet and cartridge with manageable recoil should be at the top of the list.
Once you are shooting past 500 yards and out to 1k is where bullet BC is paramount. Wind drift is the biggest reason you want to shoot a high BC bullet at extreme ranges hence the poularity of cartridges pushing .264 and .284 high BC bullets.
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So you'd think but increased speed reduces time of flight. Reduced time of flight equals less wind drift and drop. If you compare a 140 grain 270 with a .531 BC going 3200fps to a 180 grain 7mm with a .659 BC going 2750, Time of flight favours the 270 all the way to 1,000 yards. Despite the inferior BC, speed trumps BC at least to 1,000 yards. There is actually less drop with the 270. Granted the heavier bullet in the 7mm would resist wind drift slightly better but if my quick calculation is correct, the 7mm is only 6" less drift at 1000 yards. At 500 yards there's less than an inch difference...in a 10mph wind. No doubt that BC eventually trumps speed but it's not always within a practical range. Granted you could bump the velocity of the 7mm a bit but even then, the 270 is still the 1,000 yard winner for drop (over 70" better if my quick calculation is correct)and very close for wind drift.
But then again Chuck says the 7mm makes the 270 dead as a dinosaur so I could be wrong...
