Velocity readings on the Woodliegh solid bullet package recommends velocities between 1800 to 2200 fps. We were having a discussion to the effectiveness on elephant brain shots with 500 and 570 grain bullets traveling at around 2000 fps. I know many of you shoot double rifles including .470's and .500's and was curious about the fps velocity span and what would still be effective for penetration in your opinion.

peashooter

My Woodleigh 500 Nitro, .510 dia FMJ 570 gr solids have no velocity restrictions.
The recommended velocity, you reference, appears on the 570 gr .510 softs box.

Dak

With a double rifle, you do not have much choice as to velocity. You generally need to shoot it at the velocity for which it is regulated - 2150 fps in the case of both the 470 NE and 500 NE. If you drop significantly below that velocity, then the point of impact of the two barrels will diverge. I have seen low velocity loads diverge by more than a foot at 50 yards.

That being said, itis possible to develop low velocity loads, especially with a lighter weight bullet. For example, in the .500 NE I have a 1400 fps lead load. But that load is far to slow to ever be considered for use on elephant heads.

However, to further clarify, 1800 fps would be too slow as the old BPE rounds hit that figure and failed to penetrate, as did the original .458 Win Mag loads. Generally I would say that 2000 fps is the low end and I would hesistate to go below that.

For more information on reduced velocity .500 NE loads, you may wish to consult with a certain co-owner of a well-known bullet maker who reportedly fired 20 rounds of reduced velocity .500 NE ammo into an elephant before killing it.

500 grains
Can the opposite be said if the velocity goes much over 2150. Will the bullets converge and eventually cross?

Yes.

With large animals the velocity window seems to be in the 2000-2500 for proper pennitration with most solids, depending on the caliber, and bullet weight. Much more important to the double rifle shooter is regulation, which is highly dependant on proper velocity. It seems the best all round performance really starts at 2100, and goes up to about 2600! In many cases if the velocity is much under, or over that window, penitration suffers. Also large animals don't seem to succumb to shock much, tissue damage is what does it.

With a double rifle the faster you push a bullet the more likely it is to cross, the slower the more likely it is the shoot wide!

I understand your question relates to the combination of weight and velocity, that of course is ENERGY. I'm glad you recognize the importance of both factors. Unfortunately too many out there (Americans being the worst offenders) equate velocity alone with killing power. Such folks view time proven calibers operating at less than 25000fps as somehow lacking. Too bad, they're missing some of the greatest calibers ever invented! Now if more of you felt the same way maybe I could find more bargains!