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Adding length adds mass without adding diameter. Mass is on the top of the B.C. equation and diameter is on the bottom. If you can increase the top of the equation without increasing the bottom, the value for B.C. becomes larger more quickly than by simply increasing the scale. For example, a...

P.S. I still had the JBM screen up from running the 300 SMK numbers (using Litz BC). The drop providing by JBM was 25.1 MOA for your load at 1k. That is in the ball park of what you report from FTE/actual findings. I think something is just messed up with the wind numbers.

I can understand that the drop is accurate. Gravity affects a bullet for the entire ToF. The SMK has a longer total flight time and is therefore subjected to the forces of gravity for a greater period of time than the Berger. I think there is something askew with the wind deflection numbers...

Mass is on the top of the formula for ballistic coefficient. Diameter squared is on the bottom of the formula. If you add mass to bullet proportionately, keeping the same form/shape and just scaling it up, it will raise the B.C., but not by as much as if you had only increased the length to add...

Thank you for playing along here. I know this is probably frustrating you as much as it is me. We might even get to the bottom of this, given enough time.

All of that makes sense to me, Guy. I never meant to imply that you could just pull a number off the table for a constant wind, dial it into your scope and have the bullets hit the x ring. I am standing firm that lag time is what determines wind drift. The shorter the lag time, the less the...

I respect your accomplishments in long range shooting. I know there are other variables in determining your windage. Charlie pointed out a few that are not based on wind. The impact that wind has is very straight forward given a constant wind. It is based on lag time. I understand that in the...

Yes, B.C. values are not constants throughout the range of velocities that a bullet encounters on its way to a long range target. This can have an effect on lag time. This is far beyond the scope of the question asked in this thread. The question was asked if B.C. is the sole contributing factor...

The issue is lag time, not total flight time. It's not directly because they have more mass, it is because the bullet with more mass has a shorter lag time due to it being "more slippery".

This is a little outside of what is being discussed here, but are you sure? I believe mass comes into play in determining a drag coefficient or ballistic coefficient, but I'm not sure momentum does. Either way my premise has been that wind deflection is based on ballistic/drag coefficient and...

Please go read this thread from the beginning. What the heck, I guess I'll say it again... It's the difference in lag time.

I'll agree with that. I'm unfortunately not a long range shooter. I would like to be. It is something that interests me greatly and I have done a fair amount of studying on. I think I have a pretty good grasp on the physics behind much of it. It doesn't matter if someone knows exactly how to...

You've taken what I've written out of context. When two bullets are fired under identical atmospheric conditions, the direction of whatever wind is present does not affect one bullet more than the other. When looking at wind, one needs to look at only the vector value that is 90 degrees to the...

But there isn't more to it than that, that is all there is. The reason that your 338 is easier to shoot on windy days is that the B.C. of the 300 gr. bullet is so much higher. That bullet probably has a B.C. of over .800, correct? Bullets in the other calibers you mention struggle to make it...

I'm sorry DF, but I feel like you really beat around the bush there. You can't beat physics and the ONLY things that dictate wind deflection are lag time and initial velocity. It's a fact. Please prove me wrong with some hard evidence. I'm really not trying to start a fight here, but it...

There is no momentum without velocity (momentum = mass times velocity) and the the bullet has no velocity in the direction of the wind. Inertia could be argued to play a role here, but the heavier bullet also has more surface area exposed to wind, which negates it's benefit of mass. I believe I...

Tom, that is a good analogy. It doesn't quite capture the concept of a bullet drifting less even with a slightly longer flight time though. I think this is what is throwing a lot of people off and making them think that there must be other forces at work. Once you understand exactly what...

There's some good information in this article by Bryan Litz. The paragraph titled Understanding Wind Deflection is very pertinent to this discussion. http://www.appliedballisticsllc.com/index_files/Understanding_part2.pdf I've also heard that his book (Applied Ballistics, I think?) is very...

I didn't run those numbers, but I believe it is a coincidence. If you think about it, you could hypothetically drive that 220 gr. bullet at 4000 fps. The B.C. would stay the same (or nearly) but the advantage in wind drift would change drastically.