Hey all, I was wondering if anyone has tried these on top of their favorite 208 A Max load? Results? Hoping to use them as an alternate for when I can't get the A Max. But don't want to have to work up an other load just for them.
Hornady's 208 HPBT
- Thread starter Bigwheels
- Start date
Re: Hornady's 208 HPBT
I've got a few boxes on the shelf right now, my .308 loves them, but unfortunately i don't have a 208 Amax load to compare it to
I've got a few boxes on the shelf right now, my .308 loves them, but unfortunately i don't have a 208 Amax load to compare it to
Re: Hornady's 208 HPBT
I 've got a couple boxed and need to test them out.
Hopefully they maintain their BC better than the 208amax.
I've taken the 208amax out to 2,000 yards and the BC seems to drop off the slower it goes. The 208 amax BC seems to track to 900 yards or so but drops noticibly after that
If the 208HPBT maintains its BC like the 162amax, I'll switch to the HPBT
I 've got a couple boxed and need to test them out.
Hopefully they maintain their BC better than the 208amax.
I've taken the 208amax out to 2,000 yards and the BC seems to drop off the slower it goes. The 208 amax BC seems to track to 900 yards or so but drops noticibly after that
If the 208HPBT maintains its BC like the 162amax, I'll switch to the HPBT
Re: Hornady's 208 HPBT
I phoned Hornady, they said the 208amax and HPBT should be fairly interchaingable but to do load work up when switching from one to the other the first time.
78.0gr Retumbo max for both 208amax and HPBT, if I remember correctly
I phoned Hornady, they said the 208amax and HPBT should be fairly interchaingable but to do load work up when switching from one to the other the first time.
78.0gr Retumbo max for both 208amax and HPBT, if I remember correctly
Re: Hornady's 208 HPBT
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ida83704</div><div class="ubbcode-body">I've taken the 208amax out to 2,000 yards and the BC seems to drop off the slower it goes. The 208 amax BC seems to track to 900 yards or so but drops noticibly after that</div></div>
I used Litz's numbers in JBM and they were extremely close from 1760 to 2300 yards. The G1 will give exactly the results you describe.
John
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ida83704</div><div class="ubbcode-body">I've taken the 208amax out to 2,000 yards and the BC seems to drop off the slower it goes. The 208 amax BC seems to track to 900 yards or so but drops noticibly after that</div></div>
I used Litz's numbers in JBM and they were extremely close from 1760 to 2300 yards. The G1 will give exactly the results you describe.
John
Re: Hornady's 208 HPBT
Yeah. I love the new 225's. I have taken them out to 1950 with good results. But my question was whether the 208 HPBT, & the 208 A Max were interchangable. Just as a back up for when the A Max is backordered.
Yeah. I love the new 225's. I have taken them out to 1950 with good results. But my question was whether the 208 HPBT, & the 208 A Max were interchangable. Just as a back up for when the A Max is backordered.
Re: Hornady's 208 HPBT
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ida83704</div><div class="ubbcode-body">I 've got a couple boxed and need to test them out.
Hopefully they maintain their BC better than the 208amax.
I've taken the 208amax out to 2,000 yards and the BC seems to drop off the slower it goes. The 208 amax BC seems to track to 900 yards or so but drops noticibly after that
If the 208HPBT maintains its BC like the 162amax, I'll switch to the HPBT
</div></div>
That's how the physics works, as you approach the sound barrier from each side the drag coefficient increases...
Look at the Cd0 curve of any shape as it goes from Mach 0.2 through Mach 3 and it's quite clear.
This is why Bryan Litz has made a point to discuss the G7 values at length. The G7 curve more closely approximates the behavior of the long range target bullets and has a more linear curve in the general region that we launch bullets along (Mach 3 down to Mach 1.25)
As you approach and pass through the sound barrier the differences in actual drag from a single value approximation ballistic coefficient cause major differences.
A G1 and a G7 setup can be made to function equally well if you take many points for the BC and "band" it like Sierra does. As you approach the sound barrier you'll need far more appx. points than you will from Mach 2.5 to Mach 3.5, that's just how it works.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ida83704</div><div class="ubbcode-body">I 've got a couple boxed and need to test them out.
Hopefully they maintain their BC better than the 208amax.
I've taken the 208amax out to 2,000 yards and the BC seems to drop off the slower it goes. The 208 amax BC seems to track to 900 yards or so but drops noticibly after that
If the 208HPBT maintains its BC like the 162amax, I'll switch to the HPBT
</div></div>
That's how the physics works, as you approach the sound barrier from each side the drag coefficient increases...
Look at the Cd0 curve of any shape as it goes from Mach 0.2 through Mach 3 and it's quite clear.
This is why Bryan Litz has made a point to discuss the G7 values at length. The G7 curve more closely approximates the behavior of the long range target bullets and has a more linear curve in the general region that we launch bullets along (Mach 3 down to Mach 1.25)
As you approach and pass through the sound barrier the differences in actual drag from a single value approximation ballistic coefficient cause major differences.
A G1 and a G7 setup can be made to function equally well if you take many points for the BC and "band" it like Sierra does. As you approach the sound barrier you'll need far more appx. points than you will from Mach 2.5 to Mach 3.5, that's just how it works.
Re: Hornady's 208 HPBT
They are both in the 2nd Ed. of Bryan's book which I don't have in front of me. But, if memory serves me, the AMAX has a higher BC. I will try and remember to check when I get home.
They are both in the 2nd Ed. of Bryan's book which I don't have in front of me. But, if memory serves me, the AMAX has a higher BC. I will try and remember to check when I get home.
Re: Hornady's 208 HPBT
jrob300,
good point,
anyone know what the G7 BC is for ....
208 AMAX
208 HPBT
162 AMAX
JBM does not indicate G7 or I can't figgure it out
The G1 BC for the 162 Amax tracks really well out to 1600, don't remember at 1760
jrob300,
good point,
anyone know what the G7 BC is for ....
208 AMAX
208 HPBT
162 AMAX
JBM does not indicate G7 or I can't figgure it out
The G1 BC for the 162 Amax tracks really well out to 1600, don't remember at 1760
Re: Hornady's 208 HPBT
real quick
the G1 BC for the .208 AMAX is .648
The 208 HPBT G1 BC is .620
real quick
the G1 BC for the .208 AMAX is .648
The 208 HPBT G1 BC is .620
Re: Hornady's 208 HPBT
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ida83704</div><div class="ubbcode-body">real quick
the G1 BC for the .208 AMAX is .648
The 208 HPBT G1 BC is .620 </div></div>
Those are Hornady's published values.
The G1 for the Amax is 0.633 according to Litz's acoustic testing.
Anyone have the second book to verify the BTHP value?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ida83704</div><div class="ubbcode-body">real quick
the G1 BC for the .208 AMAX is .648
The 208 HPBT G1 BC is .620 </div></div>
Those are Hornady's published values.
The G1 for the Amax is 0.633 according to Litz's acoustic testing.
Anyone have the second book to verify the BTHP value?
Re: Hornady's 208 HPBT
Bryan either posted it somewhere or e-mailed it to me then, but I can't find it. If it's lower in Hornady's literature, it's definitely lower...
Bryan either posted it somewhere or e-mailed it to me then, but I can't find it. If it's lower in Hornady's literature, it's definitely lower...
