I address those of you which have the experience in shooting dangerous game like buffalo etc.

How much velocity is really needed for sending a 500 bullet down range with positive results on a cape buffalo?

Now after using a chrony one of my friends is disappointed because his .475 Ackley with 26 inch barrel will only do 2330 feet a second and that is one grain over Max, according to his manual. He was hoping to get the magic number of 2400 fps.

He wants to cut off 2 inches and have it Mag Na Ported. Is doing this a good idea? Also how much velocity do you think he will end up with after all is done? The muzzle jumps up to much to suit him.
Thank you gentlemen.

Nominal, 25 - 50 ft per inch on the bbl. NOMINAL -- depending on all sorts of other variables.

The mag port might slow things down a bit more. Hard to say. Certainly it won't speed things up.

Shot placement is more important than muzzle energy. (You know that.) Every game animal on the planet has been taken with a black powder muzzle loader.

In another thread in here "Pressure = Velocity ?" there's some speculation about load increases producing a straight line increase in velocity until max pressures are reached. At the point of max pressure, the load/charge increases begin to yield a flattened velocity curve.

It pays to search out a broad spectrum of load data. Different sources disagree on the data. Mfgs these days are producing "reduced" data to cover their butts from liability when some fool touches off a magnum load in a 100 yr old war horse.

I don't hunt, so I can't speculate about "killing" efficacy. In my book, no velocity is EVER "fast enough." ("I got the need, the need for speed.")

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.223 Ackley Improved Wildcat Forum:
http://www.hotboards.com/plus/plus.mirage?who=223ackleyimproved

Well, I know a couple of guys who have succeeded in bagging Cape Buffalo with .45/70's shooting 500 grain solids at 1800 feet per second or so, (at short range!!), so I gues the 2330 in the Ackley .475 is plenty good!! You know the .458 Winchester only manages about 2000 with factory loads, and, although there are better rounds, it has done pretty well since 1956!!

Minimum velocity is very very dependant upon bullet used. With a solid bullet and ranges less than 100 yards I would think that a 500 grain solid slug driven at 1650 fps and placed in the heart/lungs would get the job done. Of course this assumes you hit no heavy bone!

It has long been the established minimum that a 500 grain soft or solid at 2000 fps should be sufficient for all but the most ridiculous shots. Frontal area also plays havoc with penetration so the larger the diameter the less penetration one can expect for any given velocity (as long as the bullets point geometries are the same).

Specifically, your friend should have nothing to worry about with a .475 500 grain bullet doin 2150+ fps. That essentially duplicates the old 470 double rifle cartridges. If he is currently getting 2330 fps and removes 2 inches and is running a midrange burning powder (like Rel15 or IMR 4064) I would expect the muxxle velocity to drop off about 50 - 70 fps. This is assuming again that he has a 24 inch barrel to begin with.

The faster the burn rate of the powder the less advantage velocity wise you get from the long barrel. Typically with the midrange powders they have pretty much been burned up by the 24 in mark. If the barrel is 26 long and he is cutting it back to 24 with the midrange powder I would not expect teh velocity drop off to be as severe. If however, he is using a slow powder like Rel 22 or IMR 4831 the velocity drop off could be more severe.

Todd E

Tell your friend to keep the 26 inch barrel. No need to cut it.