Thanks guys. I share this information with the hope that it is helpful. I'm learning more about chronographs with each data set myself. Every time a recording session provides a shot with disagreement between the chronographed velocities, I think back to when I was only using a single chronograph and had no way to identify the questionable data. And I wonder if I've discarded loads with high ES and SD values because of one bogus recorded velocity.
The Oehler 35P is unique in that it's basically the equivalent of two chronographs packed into one unit - having the primary channel - plus
the proof channel. The primary channel should be expected to be the more accurate of the two over the long haul, since the Primary channel skyscreens are separated exactly twice the distance apart as the Proof channel skyscreens. The fact that you get two velocities recorded with the 35P for each bullet fired is a really
valuable benefit. When both channels are in agreement, you can be fairly confident the data are accurate/good.
I debated whether or not to include the 35P data from shot #2 in my average velocity calculation. The 35P data were in excellent agreement, so those data might have been true and accurate. But they were higher than the rest, and the 33 velocity was out of whack in comparison. Plus the PACT didn't record. So I concluded the data were of dubious quality and didn't use them for my average V985 determination.
Broz, you shoot a lot. So much that you can probably develop really accurate drops over time and likely come very close to a reasonably correct MV by back-calculating with a ballistics program. Plus if you stick with the Berger bullets, Bryan has already provided accurate BCs. The bullet I'm using now hasn't been tested to determine a velocity-based BC by Bryan or anyone other than me, to my knowledge. In addition, I don't shoot nearly as much as you, so I don't develop confidence in my measured drops the way you can with extensive shooting over loooong distance. To make matters worse, I hunt at widely varying elevations and environmental/atmospheric conditions. Up and down the mountains at various elevations. It's common, perhaps even normal, for me to engage game over sloped ground in the 15-20 degree range. One fall we took a Billy goat over a 30-degree inclined slope at 720 yards. 30-degrees doesn't sound like a lot - but it looks like alot when you're in it! Because the mountainous country I hunt in provides such variable 'environmentals' and angled shots, I find comfort in tying down the bullet BC value as accurately as possible. Then I let Loadbase 3.0 determine the corrective dope for these variable conditions and I find that LB 3.0 provides very accurate predictive dope - under all the circumstances I've experienced to date. As far as recommending a chronograph: as serious as you are about your shooting, I endorse the 35P as a quality unit, with the HUGE benefit of providing a 2nd recorded velocity for each and every shot fired.
Good to see you're making time to browse the LRH Forums and remaining engaged in our common hobby!