Hornady 178 BTHP

[RFtinkerer]

I'm just starting out in long range shooting, but I know enough that the listed 0.53 G1 BC isn't enough for the Hornady 178 BTHP. Or even realistic. I have a site that I will be able to get a 1100 yard shot soon, and I would like to make a first round hit if possible with the Hornady Superformance ammo. I am doing my own spotting, and it might be hard to see where I am landing. Has anyone characterized the Hornady 178 BTHP for either a stepped G1 BC or preferably G7? Also, would any other loaded factory ammo be better for this (308 Winchester)? I am not reloading yet. Thanks.

 

[BryanLitz]

Actually Hornady's advertised BC is only about 5% higher than I measured:

My test results:
G1 BC: .502 (average from 3000 to 1500 fps)
G7 BC: .257 (valid for full supersonic range)

It's typical for advertised BC's to be about 5% high and it's not necessarily 'inflation'. Some companies test their BC's over shorter ranges, like 300 yards, so the G1 BC is skewed toward the higher speed value which is a higher BC. Since I publish average BC's from 3000 to 1500 fps, they tend to be lower than the high speed BC's, but more accurate/useful for long range shooting.

Of course this problem is much less of a problem with BC's referenced to the G7 standard because there is much less velocity dependence with G7 BC's.

-Bryan

 

[RFtinkerer]

Actually Hornady's advertised BC is only about 5% higher than I measured:

My test results:
G1 BC: .502 (average from 3000 to 1500 fps)
G7 BC: .257 (valid for full supersonic range)

It's typical for advertised BC's to be about 5% high and it's not necessarily 'inflation'. Some companies test their BC's over shorter ranges, like 300 yards, so the G1 BC is skewed toward the higher speed value which is a higher BC. Since I publish average BC's from 3000 to 1500 fps, they tend to be lower than the high speed BC's, but more accurate/useful for long range shooting.

Of course this problem is much less of a problem with BC's referenced to the G7 standard because there is much less velocity dependence with G7 BC's.

-Bryan

Great, thanks! Looks like I'm pushing the edge of my supersonic range with a 308. That'll satisfy me. Guess it's on to a 338 Lapua from here.