Why is 2150 fps the benchmark for DGR velocity?

I keep reading about the failure of the 458 Win with 500 grain bullets to reach 2150 fps. The 470's I've read about are mostly loaded to 2150. As are many other "African" type cartridges.

Why is 2150 the benchmark velocity for these cartridges? Why not less or more?

Just curious.

Actually, you would have to dig up all the guys that came up with that number a hundred years ago. But on the bright side, 2150 fps seems to have worked most of the time. Whether that was based on laboratory and/or field experiments or not, maybe someone knows.

It also nominally represents about 5,000 ft-lb of energy which I am convinced is the upper limit of recoil punishment for most folks, including me. Less is probably not a good idea for DG.

If you use energy as the benchmark and not velocity, then you wind up back calculating the bullet speed of ~2150 fps for the ~500 gr. NE's, the 2400 fps for the 416's, etc. Ain't I clever?

quote:

Originally posted by Tex21:
Why is 2150 fps the benchmark for DGR velocity?

I keep reading about the failure of the 458 Win with 500 grain bullets to reach 2150 fps.

I cannot say why 2150 fps exactly, but at 1700-1900 fps which the original .458 achieved, penetration was very poor.

quote:

It also nominally represents about 5,000 ft-lb of energy which I am convinced is the upper limit of recoil punishment for most folks, including me. Less is probably not a good idea for DG.

If you use energy as the benchmark and not velocity, then you wind up back calculating the bullet speed of ~2150 fps for the ~500 gr. NE's, the 2400 fps for the 416's, etc.

Will,

That actually makes some pretty good sense. Yesterday was a long one and I didn't have the sense to consider energy as the goal of velocity. Now that you mention this, I can "see the light."

Thanks for clearing this up for me.

And to add to Will's approach, which I always keep in mind too: 2750 fps with a 300 grain .375, for about 5000 ft-lbs.

Consider some MV's:

1. 2100 to 2550 fps with a .475/500gr FP North Fork solid

and

2. 2500 to 2750 fps with a .375/300gr FN GSC solid

All penetrate to the same distance, approximately, in the crudely calibrated Iron Buffalo of plywood and water bags: artificial but consistent medium.

Lower sectional density bullets penetrate less.

Faster bullets hit harder on both ends of the rifle, and reach out farther, and penetrate straight and true with a Flat Nose nondeforming solid.

So it depends on the shooter, what is wanted.

It certainly seems proven in the game field too, by the likes of many posters here, with more experience than my four "real buffalo."

And it is the traditional wisdom:

2100 fps to 2700 fps: Average 2400 fps

Best all around woud be the .416 or .404 with a tough bullet of 0.3 SD at 5000 ft.lbs. of ME: that spells ".416 Rigby Class" or pushing the envelope with lesser cartridges.

The softpoint stuff is too complicated for me, but the solid guidelines can be applied to a soft if the soft is tough enough.

Close as I can tell, the 450 Nitro Express, 480 grain bullet at 2150 fps, and the 470, slightly heavier bullet, near same velocity, have been the benchmark caliber thumping rifles since around the turn of the century. Observation of these ballistics, on game, for a long time, have been they work, and with authority, if the shot is properly placed. There appears to be a noticeable difference in effect between 400 grain, and 500 grain bullets,
on game, in .45 caliber up, at 2150 fps. As mentioned earlier, they can kick hard at both ends, so to get a big jump, noticeable to the shooter and the animal, requires going up to the 510 Wells/etc.
and, recoil is nearly doubled. 70 ft-lbs of energy to 130 ft-lbs takes the .500s out of 90% of the people hunting ability to place a shot well. The 375's are noticeablly less in recoil, but, with the right bullets and situations, you can hunt anything that walks.

Another theory is that at 2150 fps, hitting a fairly solid, aqueous part of a game animal, the bullet may cause a noticeable bit of shock, hydrodynamic, that at lesser velocities, may not
be enough to get the animal to go away from you.

A LOT of the bashing of the 45/70 is that while
heavy enough to penetrate, and kill a dangerous game animal, it doesn't have enough speed to make that animal want to go away from the shooter. In other words, you can use a slower, more pointed, bullet, or slower, solid in 45/70, but all it's going to do in the short run is piss off whatever you shoot, and, during the time it takes the animal to expire, you may find yourself gored, chewed, or dead.

The blessing of the heavier bullets should be deep penetration, and broken bones. If you use
a lighter bullet then 300 grains, with more frontal diameter, you may not be assured of breaking through bone, and entering in a straight line, on big game. A 345 grain 45 bullet, at 1550 fps, on a cape buffalo may break bones, but, I promise you, unless you brain him, you are going to have one pissed off buffalo coming for you.

For a very long time, OVER 2150 fps, and you might have bullet failure, as plagued the solids in the 458 win, when it was released, and those solids, Hornady's IIRC, were only going 1900 fps. So, for nearly a 100 years, you were balancing stopping velocity, against speed that destroyed bullets, and gave little penetration due to bullet failure. That has all changed incredibly with the advent of the monometal solids, and, in the last 10 years, the options open to hunters have increased thanks to relatively cheap bullet milling machines, that allow private individuals to produce quality bullets, and get the complacent giant ammunition manufacturers to get off their asses, and start producing bullets that are in the 21st century, not the 19th.

Ray has noted that the 375 ultras with monometal bullets, at higher velocities, are now effective, rather then having bullets break up due to high velocities.

Big jump in technology may have us rethinking that 2150 fps 500 grain, 45 caliber threshold.
Now you can have a greater effective killing power, with the monometal 375's, at high velocity, without fear of the bullets failing to penetrate, without the recoil coupled with the jump to 500 grain bullets. On the other hand, many have said the hardest kicking rifle on the planet is the Weatherby 378, but, that maybe due to overly hot loads, and excessive pressure.?


GS

GS,
Nice essay, and very true, IMHO.

Here's another theory: More than 2150 fps created too much pressure for the double guns of the day.

quote:

Originally posted by 500grains:
Here's another theory: More than 2150 fps created too much pressure for the double guns of the day.

Pressure is determined by case size, bullet weight, and powder charge. In other words, a giant case, at low pressure, with slow powder, can do the same fast powder, and a small case, with high pressure, can do...
with slower, and more manageable recoil...
gs

quote:

Originally posted by GS:

quote:

Originally posted by 500grains:
Here's another theory: More than 2150 fps created too much pressure for the double guns of the day.

Pressure is determined by case size, bullet weight, and powder charge. In other words, a giant case, at low pressure, with slow powder, can do the same fast powder, and a small case, with high pressure, can do...
with slower, and more manageable recoil...
gs

True in modern times. But in 1898 there was not such a variety of powder. All the nitro express rounds were loaded with cordite. So there was much less flexibility in load development.

Here's another theory. When Cordite replaced BP in the 450 3 1/4, the first Nitro Big Bore, Cordite was put into the case until it was full.

Since Cordite comes in long strands they were just put in the case like a bouquet and chopped off for length.

It is just a coincedence that it makes the 480 Grain bullet go 2150 fps.

As the first, everyone else copied the formula when beginning their own cartridges.

Sounds logical. With everyone bringing out their own cartridges though, they were all copying the first one? Could be.

How do the BP velocities compare with the Cordite velocities? A proportional increase for all the variations of cartridge cases?

Even Taylor seems to blindly accept whatever the factories turned out. An interesting question/topic posed, though.

Since I don't remember my physics classes at all, I wonder how they were measuring velocity a hundred years ago. I should look that up.

I have found 2000 FPs works well with a 500 gr. bullet in either a 458 or a .470 but I will tell you for sure a .470 with that tad of larger cross section will hurt a buffalo more than a .458 and anyone that doubts that just has not shot many buffalo with either one of them.....The .470 kills better than most any caliber I have used..just circumstance?, perhaps, but thats good enough for me, I prefer experience to advise.

quote:

Originally posted by Will:

Since I don't remember my physics classes at all, I wonder how they were measuring velocity a hundred years ago. I should look that up.

I was hoping to read all about that in your book. I guess that just means you will have to write a sequel...

I read with great interest the article ".458 Lott, Much ado about nothing?" by Phil Shoemaker, in the July 2005 issue of RIFLE Sporting Firearms Journal.

The velocity parameter of 2150 ( or thereabouts ) was mentioned often.
In the end, the comparison of the .458 Win.Mag vs. .458 Lott was broken down as 'don't get rid of your .458 Win.Mag., unless you're going to Africa with a new rifle chambered for .458 Lott using monolithic solids...' ( paraphrased, of course ).

This kindles my interest in the ".470 AR" for sure, especially in light of what Ray Atkinson says about the 500-gr. .475 bullets in that velocity range.

Regardless of the day and age or platform we wish to launch it from, this ballistic 'magic formula' sounds like a joy to own and control.

As Mr. Spock would say --- "Fascinating."

I think that 2150 was arrived at simply because it worked well for all that used it, and the ones that came up with that figure did so by shooting a ton of elephants, buffalo etc. it held on until we got chronographs, but it was still effective under all circumstances, all things being equal...

I would say they were pretty close and 2150 probably is an ideal velocity for dangerous game or at least its close enough, not to say that 2000 or 5000 or anything in between won't won't work, it will, again all things equal....

What won't work is getting 2150 with a 300 gr. bullet in a 470 for instance, you just gave up one of the most important aspects of big bore rifle killing power, Sectional Density even though you can quote those ridiculas energy figures that mean zilch IMO...

I've SERIOUSLY looked into a couple conversions to create a 450 N2. What I've found, as mentioned earlier, is it's a low pressure round, in the 35k-40k. With 45 caliber, high pressure handguns, I've noticed a geometric increase in recoil, over 40k, for a numeric increase in velocity ( we loaded over 55K: using 28 grains of H-110 under a 345 grain 45 colt bullet, in a super tight chamber, and super strong gun). I've also found the same to be true in rifles. If you can keep the pressure down, you have a longer, more easily survived recoil. That's the problem with the 375. Everyone loads it to 60k, and it just snaps and rips( Genuis that I am, I bought 200 rounds of WEATHERBY loaded, 300 grain softs: Course, they are really low pressure ) . Same with the Lott. I'd much rather have a 40k big case, then a smaller case, at 60k, producing the same ballistics. To put it in concrete, or cordite terms, the 375 H&H was designed to work at lower then 40K pressures. However, everyone hot rods it, and the same is true of the Lott.

Still, something must be said for cheap cases, huge bullet selection, and large magazine capacity, and that comes with the 375 and Lott, not the bigger cases, like the Rigby, etc.

I think 2150, for the 450, 470 etc. is sort of a
magic number, in that if you go over that, you get that single digit increase in velocity, for geometric increase in recoil. It also certainly holds true for the 458 win, and, likewise the Lott, though I haven't played with Ray's magic powder, it would be really neat to graph velocity increase vs. pressure, in the calibers at question. Any takers? ;-)

I really wonder if the Lott might not be better served, using a 500 grain bullet at 2150, for much lower pressure, then the 2300+ Ray goes for? Still, for lion, I think I might want the extra 100fps, or more, and figure if I'm charged, I wouldn't notice the recoil.


gs


gs

quote:

Originally posted by 500grains:

quote:

Originally posted by Will:

Since I don't remember my physics classes at all, I wonder how they were measuring velocity a hundred years ago. I should look that up.

I was hoping to read all about that in your book. I guess that just means you will have to write a sequel...

Ballistic pendulum: Take a log, hang it from a rope so the flat face faces the shooter. Shoot the log; see how high the log swings on its rope. Potential energy at top of swing = kinetic energy of log after being hit. Kinetic energy of log (plus slug) after hit can be determined from momentum of log+slug after hit. Momentum of log+slug after hit = momentum of slug before hit = mass of bullet times velocity of bullet.

Dan

quote:

Originally posted by Atkinson:
I have found 2000 FPs works well with a 500 gr. bullet in either a 458 or a .470 but I will tell you for sure a .470 with that tad of larger cross section will hurt a buffalo more than a .458 and anyone that doubts that just has not shot many buffalo with either one of them.....The .470 kills better than most any caliber I have used..just circumstance?, perhaps, but thats good enough for me, I prefer experience to advise.

Ray,

Experience trumps... and you've had many folks' share.

But -- occasionally find it hard to sort through your tastes, Ray. Looks like you like the 41 calibers (416 Rigby, for instance, relying on sectional density) if I remember right. You don't like the .458 win, which will do the 2000fps, feeling the Lott is better, yet don't like the Lott because its recoil is a little stiff in some shooting positions that arise in normal hunting... but the .470 NE is better. Somewhere in this mix, I reckon quality of the bullets fits in there...

What is your ultimate preferred DG caliber?

Dan

Dan, Math was not my forte in SKOOL.

Does it matter what size the log is...?

If the log is too little, it will flop all over, and won't give an easy measure.

If the log is too big, it will barely move.

Try a few, and see what gives a good measure, then take a bunch of shots at that (and similar) logs. Since momentum is conserved (doesn't dissipate in collision), all those nasty details like how much energy is absorbed when isn't too important.

Oh yeah, one last thing: if the bullet exits the log, the measurement is a failure. The log has to CATCH the bullet.

Dan

2150 is an "artifacte" of circumstances.. exactly like the reason that the rigby .416 bullet weighs 410, not 400.. ( i need to find a copy of the letter between Rigby and kynock... not quite bubba to bubba, but it's not ultra precise engeering)

precondition
1: basically 2 powders available in the era, both cordite. english stick, and german flake. german flake offerd higher loading density (schuler (500jeffery) vs 505 gibba) which allowed for smaller cases at the same MODERATE pressure.

(note: double guns are loaded to MODERATE pressure, not low.. mid 30s to low 40s KPI.. shotgun are LOW pressure (way under 20kpi)

2ressure (specifically MAX) (invitro) is a function of burnrate, bullet weight, case capacity, power weight, and temp. (especially in the case of cordite, temp is VERY important)

3:jacketed bullets are actually far more important than smokeless powder for SMALL and medium bore CARTRIDGE rifles (in the context of the day, the 577 was a heavy medium, a common bore for specialist muzzle loaders merely 30 years before.. and 45 LIGHT muzzle loader).While today one can use jackets in muzzle loaders, this was not the case, for several reasons, at the end of the 19th century.

4: "happy" accidents. The gunmakers of the day knew that a higher SD (no flames on this, damn it.. doesn't matter if you now "know better") was far more effective on game than lower SD. This is where the phrase "heavy for caliber" originates. If you look at round like the 500 BPE vs NE, the NE uses heavier bullets, at higher speed...

and here comes our happy accident...

If one took a BPE 500 and loaded it to the BRIM with cordite and the BPE weight bullet, you find that you are driving the bullet far to fast for bullet construction of the day.. and still have safe pressure...

retry with a heavier bullet until you have a good bullet weight to observed pressure trade off.. (read:mildly higher than BPE )

you may have to change the case designa little (thicker walls, soild case head, etc)

taking max pressure, realized velocities, and bullet contruction (the holy trinity of case design then) the majic number is around 2150fps with an over .310+ SD bullet, proper constructed.

Yes, they could have gone faster/ligher.. or slower/heavier.. but USE and experience dictated the optimal weights and speeds that fit within the pressure and bullet construction envelope.

5: with today's powders, bit is POSSIBLE to have a higher MV at the same or less MAX pressure


jeffe

The letter from Rigby to Kynoch, which Nickudu posted, though short and simple does not imply the 416 Rigby was some freak accident, from either Rigby's or Kynoch's standpoints.

Also the momentum transfer experiemnts with a "log" requires even in the simplified assumptions of the experiemnts the determination of the change in height of the log's center of gravity. Good luck figuring out the center of gravity.

Will,
happy accident doen'ts mean freak .. it means they assumed, without total calculations, what the bullet would weigh.. that it weighed 410 rather than 400 is the "Accident"

controlled, fairly precise, but NOT exact from a spec in all factors.
jeffe

A 410 grain 416 scales back to a 300.32 grain 375 and a 173 grain 303 (.312) and 303 ammo was a 174 grainer.

As a matter of interest a 180 grain 30 calibre scales back to a 130.9 grain 270

Mike

quote:

Originally posted by jeffeosso:
2150 is an "artifacte" of circumstances..

I believe Jeffeosso is correct.


A bit of history may explain (or at least give a logical possibility for) what happened to arrive at approx 2150 as the velocity of Brit developed DG Rifles.

It pretty much all started with the .450 Nitro introduced by John Rigby, if I recall correctly.

That basically was the .450 BPE case, but loaded with Cordite and a jacketed bullet. I suspect the cordite used was the same formula as was originally manufactured for the .303 Enfield genre of cartridges. At any rate it definitely WAS a case full. Full enough that the cordite was loaded before the case was necked down to take the bullet, otherwise it would have been next to impossible to consistently machine-load the cordite into the cases in those days. The full case of cordite produced...voila...about 2100-2200 fps, depending on the specific bullet used.

The .450 worked very well, and for a while was "THE" DG round preferred by most who could afford the rifles & ammo, in Africa, India, Ceylon, and other like places.

Then the Brits made the decision to "outlaw" .45 rifles in some of their possessions. Didn't want the natives stealing the hunter's ammo, tearing it down, and reloading rounds for their .450 Martinis, don't you know. After all, old boy, might use it to pot some of their colonial "benefactor's", what?

So, what happened? To get around the ban, Rigby increased the bore diameter and brought out essentially the same cartridge case with the bigger bullet, and called it the .470 Nitro. H&H did something similar and brought out their proprietary .465 round. Others followed. The case still basically held the same amount of cordite and used the same weight of bullet so, surprise, it gave about the same velocity. That was quite successful and within the strength limits of the basically double-barrel shotgun actions used to make those rifles. Why "fix" something what ain't broke?

As the new cartridges also worked great for their intended use, though modified versions of Cordite had come along (Modite, Axite, etc.) there was still no reason to change velocities.

Even when Winchester brought out the .458 Win Mag, the un-necked short mag case they employed was stuffed to the gills in an attempt to reach that same successful killing power. Winchester even claimed that equivalency in its ads, despite the fact they never quite made it much over 2,000 fps with any factory loaded ammo I have tried in my .458 rifles.

I am a great fan of the .470, and prefer it to the others "just because", but I am almost equally happy with a .450, .500, or even a .577 rifle, either double or single shot. Also really like the .450/.400 and its rimless equivalent the .404 Jeffery. Never did keen after the .416 Rigby chambering for some reason, though I really like his rifles.

Beautiful!

Dan

quote:

Originally posted by jeffeosso:
2150 is an "artifacte" of circumstances.. exactly like the reason that the rigby .416 bullet weighs 410, not 400.. ( i need to find a copy of the letter between Rigby and kynock... not quite bubba to bubba, but it's not ultra precise engeering)

precondition
1: basically 2 powders available in the era, both cordite. english stick, and german flake. german flake offerd higher loading density (schuler (500jeffery) vs 505 gibba) which allowed for smaller cases at the same MODERATE pressure.

(note: double guns are loaded to MODERATE pressure, not low.. mid 30s to low 40s KPI.. shotgun are LOW pressure (way under 20kpi)

2ressure (specifically MAX) (invitro) is a function of burnrate, bullet weight, case capacity, power weight, and temp. (especially in the case of cordite, temp is VERY important)

3:jacketed bullets are actually far more important than smokeless powder for SMALL and medium bore CARTRIDGE rifles (in the context of the day, the 577 was a heavy medium, a common bore for specialist muzzle loaders merely 30 years before.. and 45 LIGHT muzzle loader).While today one can use jackets in muzzle loaders, this was not the case, for several reasons, at the end of the 19th century.

4: "happy" accidents. The gunmakers of the day knew that a higher SD (no flames on this, damn it.. doesn't matter if you now "know better") was far more effective on game than lower SD. This is where the phrase "heavy for caliber" originates. If you look at round like the 500 BPE vs NE, the NE uses heavier bullets, at higher speed...

and here comes our happy accident...

If one took a BPE 500 and loaded it to the BRIM with cordite and the BPE weight bullet, you find that you are driving the bullet far to fast for bullet construction of the day.. and still have safe pressure...

retry with a heavier bullet until you have a good bullet weight to observed pressure trade off.. (read:mildly higher than BPE )

you may have to change the case designa little (thicker walls, soild case head, etc)

taking max pressure, realized velocities, and bullet contruction (the holy trinity of case design then) the majic number is around 2150fps with an over .310+ SD bullet, proper constructed.

Yes, they could have gone faster/ligher.. or slower/heavier.. but USE and experience dictated the optimal weights and speeds that fit within the pressure and bullet construction envelope.

5: with today's powders, bit is POSSIBLE to have a higher MV at the same or less MAX pressure


jeffe

Idiots guide to dangerous game hunting:

2150 with a 45 caliber 480 grain bullet is the baseline, based on the 450 Nitro, that has worked in Africa, at low pressure, under 40K, in doubles, since the end of black powder. In other words, the vast majority of animals, when shot with that combination, fall over, and, go boom, for about 100 years. Millions of elephant, and buffalo, are going to testify to this fact on the next plane of existence.

A bunch of stupid americans, READ WINCHESTER, tried to sell the hunting world on their 45-70 version of the 450 N2, called the 458 win mag, even though it's not really a mag, since it's too short, and the velocity is too low, but, you can sell bullshit for nearly 40 years, pretty much only in america on this one, and then people wise up, in the gunworld.

GS