Nosler .358 225 AB and PT Ballistic Coefficients?

atmoshpere · Jan 30, 2013

The listed BC for the 35 cal 225 AccuBond is .421 while the BC for the 225 Partition is .430.

Does anyone else find this odd?

It just seems counterintuitive that a boat-tailed, ballistic-tipped bullet would have a lower BC than a flat-based, shorter bullet of the same caliber and weight.

Not that it'll matter much in a 358 winny!

JD338 · Jan 30, 2013

This has come up before.
I can't explain it.

JD338

gerry · Jan 30, 2013

I have always found it odd too, the AccuBond has to be higher than the Partition.

Here are the 225 gr Partition, 225 gr AccuBond and 250 gr Partition.

onesonek · Jan 31, 2013

Only rational explanation I can think of, they are mathmatically figured and it's just a glitch in the program, or typos of some sort.
When I ran comparisions on these two out of curiosity, I just did some correlations to another caliber of like SD's. The .420-.430 seems about right to me for the PT, and gave the AB .100 on top of that, which is a close avg. to other calibers. A .010 point or two just won't that much difference to reality. More than that can change in TOF anyhow. It isn't a perfect solution of course, but close enough for me.

FOTIS · Jan 31, 2013

Shoot them at 500 yards and verify them yourself. Something everyone should do with all their LR loads.

onesonek · Jan 31, 2013

Yep, I totally agree.

barthowes · Jan 31, 2013

I brought this up before and it never got straightened out. There is no way a Boattail bullet that is longer can have a lower BC that that of a flat base of the same weight. Even if they were switched, they shouldn't be that close. The 225 gameking which is BT is only .380. I would put monet on the PT being incorrectly high.

atmoshpere · Jan 31, 2013

Given my delivery system for these two bullets I won't be taking shots on game in excess of 300 yds, so from a practical standpoint the numbers don't really matter as I will be shooting to 300 before ever fielding the round. It was just a curiosity thing on my part. I also read an article, http://35cal.com/35bullet_study/35bullet_study1.html, where the authors final decision to choose the PT over the AB seemed to be based on nothing more than the listed BC. To be fair, he had years of experience with the PT and it's performance on game so he was confident with its abilities, and the AB was newer on the scene. It just got me to wondering if anyone had tried to verify either number with a cartridge they actually shoot to 500 yards. In any case, it sounds like either offering would be great candidates for "all-around" bullets for hunting whitetail to moose, which I already knew because you guys told me :mrgreen:

tjen · Jan 31, 2013

As all the AB's the 225gr should have a high B.C.. But the PT is longer than the GK-BT and that may just give it the advantage even thu the GK has a boat tail. And its BT is not much compared to Long range Low drag BT's. And they are both spitzers with very simular frontends.

I decided to use the 225gr PT in my 358win and the 225gr AB in the whelen.

onesonek · Jan 31, 2013

Yes, it is a couriosity indeed. But like your thoughts at 300 yards or so, the flight characteristics between the AB/PT really don't matter, other than accuracy. Personally I would prefer the PT myself with the use's mentioned, if the MOA accuracy of either in one's loads are close.