BC, Velocity, Velocity SD, or Dispersion?

[nm.otter]

Educational

 

[hereinaz]

For hunting, the drama is overblown and pretty much academic once you choose a decent bullet and get decent velocity.

This is a group at 2960ish gps at 680 yards out of my 22 Creedmoor with 80 grain ELDm “seconds” from Midway, loaded in my Dillon 750 progressive in virgin brass straight out of the bag with 6.5 Staball powder thrown volumetrically. The powder had sat in the hopper for weeks. And, just I eyeballed the seating depth to set the base of the bullet just above the shoulder and made sure it chambered.

ES was over 100 and SD was like 20, I don’t remember cause all I was paying attention to was the average/mean to plug into AB.

This was one wind hold, basically the left side of the plate, on a 30” wide plate, lol. so there was definitely some wind. I was just doping the rifle out to distance, so correction for wind wasn’t made.

Yes, I realize BC and Velocity can affect wind drift, but that goes back to first principles of choosing a decent bullet fast enough… an 88 vs 80 might have less wind drift, but how much less?

For hunting, I have typically chosen a 115 in 6mm, 134 in .25 and 180 in 7mm, all high BC and a cartridge/barrel length to get me to 3000-3100 fps. That always felt like a sweet spot to me, given the other considerations to go faster.

I do like to listen to Hornady, always something new. It’s always got a marketing slant/bias, but they present ballistic data in a meaningful way.

 

[steelheadmike]

I recently listened to a podcast with a top PRS shooter. I don't subscribe to everything PRS guys say, but I pay attention when they start talking about how they approach their loads. He said that one of the biggest mistakes he sees is that guys "chase bullets". Basically, people spend way too much time worrying about their load development and not enough time worrying about reading wind or practicing positions.

Admittedly, I'm guilty of this and have been trying to shoot more and worry less about what happens before the primer goes off.

 

[streamerfish]

I probably need to listen to it again, as I was only half listening while working, and they were moving fast through data.

I do remember thinking 15 minutes in....129gr interlock...they make those..lol.

It was a fun exercise in when b.c. matters...and when it doesnt.

Comparing shot group standard deviation to wind drift at certain b.c. of bullets was interesting, never really thought about comparing say a .7moa .5bc bullet to a say 1moa .6bc bullet in different wind conditions. Or at least never thought about it that way.

I need to do some thinking and math on that.