Heavy bullets vs.light bullets

[Bart B]

So provided BCs are valid at velocity, lower BC bullets ALWAYS drift more with a given wind than higher BC bullets, regardless of velocities.

Here's an example of the opposite happening as calculated by Berger Bullets' software:

Sierra 200-gr. HPMK, BC=.560, leaving at 2000 fps, 10 mph crosswind, at 1000 yards drift = 119 inches

Sierra 155-gr. HPMK, BC=.470, leaving at 3000 fps, 10 mph crosswind, at 1000 yards drift = 91 inches

Lower BC bullet leaving faster drifts less with a given wind than the higher BC bullet leaving slower.

 

[Nimrod1203]

There is an old saying that "speed kills". I believe it was the .220 swift the military tested for penetration, and since it was breaking 4000 fps, or hypersonic, it was out penetrating a 300 win mag. Really unless you get to very extended ranges, light and fast is just fine. On coyotes, inside of 400, I'd go light and fast. I grew up shooting a 700 .270 with a 90 gr hollowpoint at 3600 fps. I never seen any disadvantage, but i never got over 400 yards either. Some people think BC is everything, but really it's a non-issue inside of extended range. BC won't shoot any more accurately either it just bucks the wind and delivers a more linear flight path at extended range(past 600 yards).
Nimrod

 

[Mikecr]

Then I'm wrong Bart. Thanks for pointing it out.
I need to go back & better understand it.

 

[Edd]

The reason velocity can trump BC is because of the decreased time it takes the bullet to reach the target.

 

[Bart B]

The reason velocity can trump BC is because of the decreased time it takes the bullet to reach the target.

With both bullets having the same time of flight to the 1000 yard target and 10 mph cross wind, the heavier one with a higher BC drifts less.

Sierra 155-gr. HPMK, BC=.470, leaving at 3000 fps, 1.5145 second TOF, at 1000 yards drift = 90.6 inches

Sierra 200-gr. HPMK, BC=.560, leaving at 2807.2 fps, 1.5145 second TOF, at 1000 yards drift = 78.5 inches

For the 200 grain one to have the same drift as the 155:

Sierra 200-gr. HPMK, BC=.560, leaving at 2545 fps, 1.6933 second TOF, at 1000 yards drift = 90.6 inches

As long as the 200 has a time of flight less than .1788 seconds longer than the 155 leaving at 3000 fps, it'll drift less.
That is, if my math's right. I don't do these things too well any more.