Has anyone verified the 90gr a-tip B.C.?

[InkedIan]

Has anyone verified the 90gr a-tip B.C.?

 

[Ned Ludd]

This is not a direct answer to your question, but might be of interest. I routinely use the LabRadar velocity drop data and plug the numbers in at JBM Ballistics to estimate BCs. There are certainly caveats to doing this, most obviously the relatively short distance over which velocity drop is measured (55 yd). Nonetheless, I have done this repeatedly over a couple years with a wide range of different Berger bullets and the BC estimates for unpointed bullets come very close to Berger's box values, whereas the BCs estimated for pointed bullets are typically from 3% to 6% over the box BC value.

In my hands, pointed Berger 90 VLDs routinely generate G7 BC estimates of around 0.290. I have also estimated the BC of the Hornady 88 gr ELDM bullet on one occasion. I came up with a G7 BC estimate of 0.306, which was noticeably higher than the value determined for 90 VLDs the same day, using the same rifle, and noticeably higher than Hornady's published value of 0.274. The design of the 90 gr A-tip does not look dramatically different than the 88 ELDM by eye, other than the 2 gr weight difference. So it would not surprise me if the 0.295 G7 BC advertised by Hornady is correct, possibly even a bit conservative. Obviously, only actual testing can definitively answer your question, but Hornady is certainly getting good BC numbers from the 88 ELDM, so I can only assume the 90 A-tip would be even higher.

 

[InkedIan]

This is not a direct answer to your question, but might be of interest. I routinely use the LabRadar velocity drop data and plug the numbers in at JBM Ballistics to estimate BCs. There are certainly caveats to doing this, most obviously the relatively short distance over which velocity drop is measured (55 yd). Nonetheless, I have done this repeatedly over a couple years with a wide range of different Berger bullets and the BC estimates for unpointed bullets come very close to Berger's box values, whereas the BCs estimated for pointed bullets are typically from 3% to 6% over the box BC value.

In my hands, pointed Berger 90 VLDs routinely generate G7 BC estimates of around 0.290. I have also estimated the BC of the Hornady 88 gr ELDM bullet on one occasion. I came up with a G7 BC estimate of 0.306, which was noticeably higher than the value determined for 90 VLDs the same day, using the same rifle, and noticeably higher than Hornady's published value of 0.274. The design of the 90 gr A-tip does not look dramatically different than the 88 ELDM by eye, other than the 2 gr weight difference. So it would not surprise me if the 0.295 G7 BC advertised by Hornady is correct, possibly even a bit conservative. Obviously, only actual testing can definitively answer your question, but Hornady is certainly getting good BC numbers from the 88 ELDM, so I can only assume the 90 A-tip would be even higher.

Interesting you came up with such a high b.c. for the 88s. I used the box G7 for the 88s and it was on point out to 980yds in a 7 twist 223 Wylde at 2840ish fps.

 

[Ned Ludd]

I was quite surprised when I first determined that BC for the 88s. I only shot them out to 600 yd, but as I recall the predicted drop was very close. If I hadn't shot pointed 90 VLDs side-by-side from the same rifle on the same day, I would've been tempted to just call it a fluke. Having said that, I only bought a single Lot of the 88s and it could have been something special about that particular Lot, rather than a general trend across many different Lots of 88s.