You would need to calibrate the two chronographs to each other by putting one right after the other and shooting over them to see if one consistantly reads higher than the other and by how much; then swaping their positions and doing it again. Hopefully you'd be able to find a repeatable pattern you could use to correct your velocities from one to the other. If they average the same but differ by a random amount shot to shot you aren't gaining a whole lot--but hopefully that wouldn't be the case.
Done with two good chronographs calibrated correctly, of course will be more accurate. But not many have access to two Oehlers. I don't think that means they should do nothing.
Doing it with one good chronograph is certainly better than nothing--which is what most are doing right now. When SD's are in the single digits and one bullet on average loses 30, 50, 100 or 170 fps more than another, you may not have a number down to the last .001 with enough statistical assurance you'd bet the mortgage on it, but you sure have better data than when you started. You'll be in the ballpark.
I thought that HBC (Benchrest Central) did some testing on the 6mm wildcats and reported that the stated BC's were marginal at best? Obviously this doesn't mean anything for the rest of the bullets offered by Richard. I'm not one way or another on this subject. I'd just like to see repeatable comparisons. Would there be any merit with comparisons of bullets drop to another manufacturer at the same velocity and range? In other words can we skin the cat another way?
Thats what we have been trying to do but everytime someone posts any data from this type of drop testing all haties breaks loose.
Its accurate enough data to get a guy on target at extreme range but many feel it is not good enough to establish a BC off from. They may be correct, I do not know, all I know is I can hit the targets I shoot at using the derived BC values I get from bullet drop testing.
Hitting the target is about all I care about.
Allen Precision Shooting
Home of the Allen Magnum, Allen Xpress and Allen Tactical Wildcats and the Painkiller Muzzle brakes.
What I'm saying is rather than reverse engineer the BC figures from drop tables which we all know can vary quite a bit due to other factors. Why don't we just take a known competitor's higest BC bullet and shoot a Wildcat along side it and post the differences in drop. This would leave the numbers out of the equation but still give us a comparison that we can relate to.
I don't think there is much merit to someone else's observed drops by itself. Condition's or comparisons are really needed.
If somebody reports that a bullet requires less drop compensation than another, under same conditions, it means to me that the bullet has higher BC. Thats all.
If someone calculates a local/apparent BC of .XXX, but can't provide further -qualifying information, then I can't find a real use for it. There is just no way to back convert apparent BC from Montana into a sea level standard BC for comparison with other bullets without knowing the conditions producing the data.
It's all good to hear though. And queries for further info should not automatically be taken as an attack. Atleast, not from me. Questions=Interest.
I am planing on shooting a few bullets with High bc's when I test the 200's. I am going to shoot the 175 Sierra SPBT and Noslers 160 Accubond. No store around here has any Berger 180 VLD's and it could take up to 3 weeks to get them if I order them so I am going to see if I can find a box of 162 A-max bullets since they have a bc of .625. As for using two Chronographs I am just going to use the one Pact I have and move it to a couple of different ranges. As for Elevation I will be shooting at 850ft for the 300 yard target and the bench will be at 853ft. The target is 4ft tall so I should not be shooting at a down angle. I guess we will see what happends when the 200's get here.