Was in the desert yesterday shooting my 31" Kreiger 338 barrel with 285 ELD. Previously I took them to 1500 and the new advertised .417 BC seemed pretty spot on. I see that previously they had it at .395 in the first edition of the reloading manual that had the new ELD listed.
I was about 1.0 mil too low. So I got out the Labradar and checked velocities with 7 shots (SD 7.5 fps) - they were about 45 fps lower than I expected perhaps because of temperature sensitivity of N570. Fine, I corrected that. But it accounts for only about 0.5 mil of what I need to get on target.
I put the PLRF15 on a tripod and repeatedly ranged the target and the ground around it. 1780-1782 over and over. I'm pretty confident that is the correct range. Next time if I have 2 vehicles I will range a vehicle at the shooting location from the target.
Atmospherics all confirmed and shots repeated at lower temps after sun went behind mountains.
The only remaining explanation is that the .417 BC is an overestimate. If I use 0.40, very close to the previous value of .395 or the AB/Litz value of .397 it shores everything up. For TRASOL that is. For AB app, I'm STILL a mil too low with all that information.
Don't want to turn this into another TRASOL versus AB thread. All I need is the data to line up with my shooting using my equipment. With the equipment I use, a BC of about .400 for these bullets is more realistic than .417
I was about 1.0 mil too low. So I got out the Labradar and checked velocities with 7 shots (SD 7.5 fps) - they were about 45 fps lower than I expected perhaps because of temperature sensitivity of N570. Fine, I corrected that. But it accounts for only about 0.5 mil of what I need to get on target.
I put the PLRF15 on a tripod and repeatedly ranged the target and the ground around it. 1780-1782 over and over. I'm pretty confident that is the correct range. Next time if I have 2 vehicles I will range a vehicle at the shooting location from the target.
Atmospherics all confirmed and shots repeated at lower temps after sun went behind mountains.
The only remaining explanation is that the .417 BC is an overestimate. If I use 0.40, very close to the previous value of .395 or the AB/Litz value of .397 it shores everything up. For TRASOL that is. For AB app, I'm STILL a mil too low with all that information.
Don't want to turn this into another TRASOL versus AB thread. All I need is the data to line up with my shooting using my equipment. With the equipment I use, a BC of about .400 for these bullets is more realistic than .417
