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Old 04-19-2005, 08:08 PM
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Roskoe
 
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Default RE: heavies in a 22-250?

Faster bullets have less wind drift; but heavier is better when the speed is the same - or more precisely, when the time of flight to the target is the same. For instance, the 100 grain Sierra .243 spitzer and the 180 grain Sierra .308 spitzer both have a ballistic coefficient of about .460. So their time of flight to the target is the same, and the trajectory is the same out to infinity - at any velocity, so long as they have the same muzzle velocity.

But the wind drift, at 500 yards in a 10 mph crosswind, is 20.3 inches for the .243 and only 16.8 inches for the heavier .308 bullet. (both bullets going 3200 fps) This really jumped out at me when I was reading an article in the American Rifleman quite a few years back that compared the trajectory and wind drift of the .300 Weatherby and the .50 BMG. The trajectory is really close - but the BMG's 750 grain bullet has about 1/2 the wind drift at long range.
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