Thread: New Defence Force rifles need firing pins replaced

Originally Posted by Cordite

@Cowboy06

Correct, but only at the end of the bullet's useful flight path, therefore it is not quite correct to state that a flat base spitzer will lose velocity and energy 'a lot quicker' than a boat tail.

There is no advantage from boat tail bullets at ethical hunting distances, only disadvantage, if you never need to shoot animals more than half a K away. (OK, boat tails are easier to seat when reloading, but really!)

At supersonic speeds the front ogive is what matters in reducing velocity loss. The lead and copper going into forming the boat tail is better used for forming a longer ogive at the front of the bullet when hunting distances are involved. To increase your supersonic range, you need a long slender spitzer more than a boat tail.

Boat tail spitzers only have significantly lower drag than flat bottom spitzers once they both have slowed to transsonic/subsonic velocity. Only at that point do boat tails really start showing significantly less velocity drop than the equivalent weight spitzers. But note, the boat tail only helps conserve trans/subsonic velocity, a bit like a coffee mug that is only insulated at the bottom third to keep the dregs warm. The boat tail is thus for target bullets or for long range sniper bullets (where instant kill vs wounding vs slow kill is less important) but making an accurate long distance hole is everything.

For subsonic / transsonic loads however, a long boat tail is useful right from the muzzle, and a round nose better as it keeps centre of gravity forwards, something that is hard to do with a spitzer shaped for supersonic flight. The "ideal" subsonic hunting projectile is thus similar in shape to a Berger VLD flying backwards!

I’m not sure your understanding of BC is as strong as you think it is.

Drag is drag so it’s entirely accurate to state that a flat base spitzer will lose velocity and energy faster than a boat tail.