Re: 6.5 x 47 Lapua to 1 Mile
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MDM</div><div class="ubbcode-body">
That's interesting, do you think the tangent vs. secant o-give has something to do with your findings? I would have thought the higher BC projectile would do better, but bc must be a moot point when it comes to the super sonic transition. </div></div>
Correct: The higher BC bullet will delay transition effects because velocity is retained for longer distance, but the higher BC bullets in jacketed form have a tendency to show transition issues.
Nose shape is far less significant than the tail of the bullet.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mudvayne</div><div class="ubbcode-body">
When I shot the 130 JLK at 2000, though I did indeed get a hit and it impacted sideways on target, the shots were splashing as much as 4 mils apart. They didnt fare too good at all. Good to see We are getting similar data. What was your muzzle velocity and conditions bohem? </div></div>
The DA is a short hand approach to the conditions. If you log the altitude, temp, and pressure you'll be no farther than +/-1.5% from getting the humidity in there too.
The density difference at 0% vs. 100% humidity is only a 3% change in the density.
I don't have the notes any more about the temp and pressure of the day, just the end result of the DA.
Memory says that the best conditions I ever shot the Bergers and JLK's under was about 85-90F, 29.4 inHg, 70% r.h. at a range 1000' ASL.
I shot them without issue to hit 1 foot squares at 1740yd, impacts were consistently MOA or less vertically, wind out there was pushing the groups a little larger overall.
This was from a 6.5-06 throwing the 140 Berger at 3200fps. When the same rifle was slowed down to throw them at 2900fps I could not keep them inside of a 10 foot circle at that range. The transition point was predicted appx. 80yd in front of the target at the slower MV.
