BC & Profile Flat Base vs BT

[D.B. Cooper]

I noticed today, while setting up dope cards, the Hornady FMJ-BT (HRN3037) has a lower BC than the PPU flat based bullet (B-099). (.398 vs .413) in 150 grn 30 cal. I'm not sure if that is a significant difference or not, but it seems odd, to me at least, that the BT bullet would have a lower BC.

Hornady publishes a G1 profile for their bullet, whereas PPU does not publish a profile; does anyone know what it might be for a flat based projectile? (I used G1 in the ballistics calculator to fill out the dope card.)

 

[tmd16556]

PPU bullets seem to have a really long point profile compared to Hornady bullets. That probably makes up for the base profile. The 150 Hornady boat tails are pretty short too.

 

[AJC1]

If you are shooting a 150 class bullet your primary in mid to short range. Why is the bc that big of deal. Consistency is the most critical aspect of any bullet and I dont see those quality controls on ppu. Maybe someone with a lab radar has shot these and can give you some usable numbers.

 

[D.B. Cooper]

If you are shooting a 150 class bullet your primary in mid to short range. Why is the bc that big of deal. Consistency is the most critical aspect of any bullet and I dont see those quality controls on ppu. Maybe someone with a lab radar has shot these and can give you some usable numbers.

I don't disagree with anything you said here. BC is important in this case with a ballistics calculator to figure out sight adjustment at different ranges. In other projectiles, BC is important with the calculator to have an accurate idea of velocity at different ranges so as to know how far I can shoot and still get good expansion. (Not an issue with target projectiles.)

 

[Demi-human]

Why is the bc that big of deal.

Wind correction. It’s not a big deal, just have to know it.

Consistency is the most critical aspect of any bullet and I dont see those quality controls on ppu

This is the deal.