.300 Wby / 180 Accubond

[Doug Beach]

Helping an acquaintance get ready for a hunt. He is using a .300 Wby, with factory Wby 180 Accubond ammunition. In an attempt to generate an accurate trajectory chart for him, I chronographed his ammo (3270 fps). We then shot at 200 & 600 yards. He was 4" high at 200, which corresponds to an approx. 315 yd zero. He was 55" low at 600. This in no way corresponds to the Litz trajectory on JBM, being about 2.5 MOA lower on the target than expected. I'm wondering if we're having bullet tip deformation problems, due to the relatively high muzzle velocity. Anyone else play with these bullets at these speeds & distances?

 

[Doug Beach]

My next step is to pull a few of his bullets and seat 175 SMK's in their place, and see if that trajectory makes more sense. If so, we'll try other hunting bullets.

 

[Schism]

I recently read a thread on another forum about Nosler published BC numbers. Most of the experienced guys determined Nosler has inflated their BC numbers because real world experiences like you are seeing. I don't know what is correct but I always use real world data over calculated data when I have it.

 

[Doug Beach]

I am using Litz's numbers, which are generated in the real world. If I read his data correctly, he tested them at a much lower MV, perhaps 2500 fps. I'm wondering if the much higher MV is creating a problem.