Bryan Litz seems to test a lot of bullets BCs against manufacturers data. Absent being able to test them yourself, who would think has the more accurate data?

Bryan's ballistic app shows his calculations. Some are considerably different in either direction. For example, Nosler gives the 200 grain 338 Accubond and BC of .417 but Bryan tested it at .461. Nolser gives the 120 7mm Ballistic Tip a .417 but Bryan gives it a .365.


http://appliedballisticsllc.com/ballistics/

I would side with litz.

Every time.

but???

Litz has forgotten more about ballistic's than most will ever know.

Litz is the man when it comes to true BC.

Litz every time

Thanks everyone. I figured Litz was the right answer but wanted to confirm with the long range shooters that get to test many of the published BCs at long range.

Litz. I was told several companies are having to restate the posted bc's on their boxes for overstating them.

Actually works in my favor for my 338 Federal. Both the 180 Accubond and 200 Accubond showed materially higher with Litz's data which was the exception for Nosler. They were almost all overstated as a brand.

Litz is human and does make errors, but I go with his numbers first always.

His numbers have always been spot on for me provided the other data I put in was correct.

what is his phone app, bc calculator called?

Applied Ballistics.

Kestrel 4500 with Applied Ballistics is as Caddilac as it gets!

Just got a 5700AB with blue tooth and it's very nice.

100% Litz. Nosler is the absolute worst for inflating their BC's. Sierra is next.

But most shooters see or use only the G1 BC stated at the max velocity. Often times your actual velocity is lower than the G1 BC stated at the top speed.

Also, if you are shooting a boat tail bullet, you need to run the G7 BC, not the G1 BC. The G1 drag profile is for a flat base, lead soft point bullet. The G7 drag profile is for a BTHP design, which most bullets are these days. I run a G7 on ALL my trajectory data, and never look at the G1. The G1 is a misleading number for many bullets, depending on the speed at which it was calculated at.

I was curious about the G1 G& thing. Thanks!

Good advice on G7. I was just quoting G1 because it's all Nolser lists for comparison.

For example, look at the Sierra 175 grain MatchKing. Below is the Sierra listed data for this bullet.

Sierra book data for G1 BC.
.505 @ 2800 fps and above
.496 between 2800 and 1800 fps
.485 @ 1800 fps and below

Also, the Litz G1 BC average is .473 and a G7 BC of .243. So even the Sierra book data is a little elevated, which is common.

As the speeds slow down, your G1 BC decreases. As the speed increases, your G1 BC increases. If you are shooting this bullet out of a 308 Win at 2650 fps, then you should be running the .496 G1 BC. But as it slows down, the G1 BC decreases, and you need to account for this increase in drag. If a bullet company lists their G1 BC at 3500 fps, and you are running your rounds at 2500 fps, your drop data will be significantly off. This is the discrepancy problem common on G1 BC data.

The G7 BC is a different drag model from the G1, and does not have as much issue with the discrepancy as the G1 does. This is why it is much more consistent to use for modern bullets.