I don't know who coined the phrase, but I know some of us have been referring to rounds like the 577 T-rex as dinosaur rounds. I was curious, what exactly the criteria one would use for defining a dino gun. I would think the threshold would be 50 cal 750 gr @ 2400 fps, or 585 900 gr @ 2400 fps, and on up from there.

So, what calibers do you think qualify as dino guns?

Paul H,
You knew you'd get me to respond to this one, didn't you?

I may not have coined the phrase "dinosaur gun" but I have formalized a definition of it. The Bwana Saeed Index involves the creation of three classes of African big game rifles:

TR (true hunting rifle) BSI = 100 to 199
SR (stopping rifle) BSI = 200 to 399
DR (Dinosaur rifle) BSI = 400 and up

The basis of this is the 577 Tyrannosaur with 750 grain bullet (.585 cal) at 2447 fps muzzle velocity. This is exactly 400 BSI. For practical use as a stopping rifle, the T. rex should be loaded below this velocity, otherwise it becomes a stunt gun, or dinosaur gun.

A .510 bore can become a DR by using a 750 grain bullet at 2150 fps. The BSI of this load is 403. This happens because the sectional density of the .510" 750 grainer is an outlandish 0.412 as compared to the .585" 750 grainer at 0.313.

The T. rex with a 900 grain Woodleigh (s.d.= 0.376) at 2200 fps has a BSI = 519, well beyond the DR threshold.

The 700 grain AP .510" bullet (s.d.= 0.384) at 2451 fps has a BSI of 400, which just barely makes it into DR territory.

Some other notable dinosaur guns:

600 Nitro, .622" 900 grainer (s.d.= .332) at 1950 fps, BSI = 432

700 Nitro, .700" 1000 grainer (s.d.=0.292) at 2000 fps, BSI = 487. The T. rex with 900 grainers at 2200 fps beats this.

However, Saeed's 700 Nitro pushing 1000 grainers at 2450 fps has a BSI of 597. Finally something that can beat the T. rex, even with a modest 1000 grain bullet of only 0.292 sectional density.

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Good huntin' and shootin',
RAB

RA,

You always leave out the main one!!

RF: Anything over 505 Gibbs the causes violent "Reflux" and fouls the scope lens.
the opposite of "whump" as for every action there is a reaction...

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Ray Atkinson

ray@atkinsonhunting.com
atkinsonhunting.com

Ray,
Now I must take you to task. Since you coined the term "whomp," I must insist that you stick to the original spelling rather than try to change it to "whump."

Whomp is the Atkinsonism for BSI.

Note that the whole point of the DR classification is guidance for those whose sphincters aren't as tight as they used to be. If you stay below 400 BSI you are less likely to reflux on your scope. That can get messy.

BTW, what is the "main one" that I am leaving out?

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Good huntin' and shootin',
RAB

Ron,

I dunno, I think that dino's have extra thick skin, and hence would need extra penetrative capabilities, perhaps a sd of .35, or .40? I think the 50 bmg would be kind of akin to the 375 on thick skin African game, and it would go up from there. I think a 577 T rex w/ 900 gr solids at 2400 fps would instill confidence in me, and I'd want a 15# gun, with a muzzle brake!

Paul H,
Even the T. rex would have trouble getting the 900 grainer up to 2400 fps. Under your system, only Saeed's 700 Nitro could qualify as a DR. And even it could not meet your sectional density requirement with its mere 1000 grainers.

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Good huntin' and shootin',
RAB

So RAB just how do you work out the BSI, I remember it has something to do with the Taylor index, which I also don't know how to work out.

Scott

"If my government doesn't trust me with my guns why should I trust them with theirs'"

RA RA RA,

You are just confused...

"Whump" is what one gets on the butt of the rifle on the shoulder as a result of recoil that puts his dip of snuff in the scope lens...

"Whomp" is the impact effect of a bullet on game..

So when you fire you get a quick whump-Whomp at the exact moment. I have heard it a million times and I'm sure you have to.

Why do I have to explain everything to you RA??, this is such basic stuff, it's embarassing to me and my friends in outer space.

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Ray Atkinson

ray@atkinsonhunting.com
atkinsonhunting.com

For optimal penetration & destruction on the dino-class game, I'll stick to my BMG. Now I just have to decide on AP or API ;-) (Roufous is too expensive. Well, ok mabey just one)

BBS,
Rather than bore everyone else with another BSI rendition here, I will direct you to the "African Big Game Hunting" forum where you will find a couple of threads that explain it: "BSI: Accounting for Rifle Potential on Big Game" should be read first. Find it on page 4 of the current listings. Then go to (also on page 4) "Bwana Saeed Index: Simple Arithmetic" for further discussion.

Finally, on this forum, on this very page, look at "Big Bores for the Big Five:..."

There is no better method for easily comparing the payload delivery capability of all the big bores of sporting use.

Ray,
Thanks for clearing that up for me. I learned a new Atkinsonism. "Whomp" is what the game animal/target receives, this is what BSI measures. "Whump" is what the shooter perceives on his shoulder. Good point.

BMG,
I agree that the 50 BMG would be an excellent DR, but only if you could tolerate the recoil in a 15 pound gun. Any heavier gets impractical to chase dinosaurs on foot with.

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Good huntin' and shootin',
RAB

Speaking of exploding shells, I'm surprised that no one has dared to recreate Sam Baker's "Jennah al-Mootfah": 3500 grains at something on the order of 900 to 1300 fps. He loaded the hollowpoint with a 50:50 mixture of SbS and KClO4 (impact & friction sensitive!). It weighed over 20 pounds and even he (Mr. 4-Bore) hated to shoot it. Now that surely is a gauntlet to the chops! Personally I am content with a mere stopper but I derive much amusement from the R&D efforts at this site.

Given the degree of seriousness we give a lion, elephant, etc. compared to, say, elk, it appears we tend to want to make sure anything willing to waltz over and do the rhumba on our anatomy is real dead.

Imagine a 16,000 lb animal, 35 feet long, with a 4 foot jaw full of 6 inch teeth, having a VERY small brain, capable of moving at 35MPH with fair agility. Something that would treat a heard of full grown elephants as zero danger steak-ums, or disembowel, behead, and utterly destroy a kodiak with nothing more than a play bite.

We would have a class of weapon which employed explosives, maybe a shaped charge, something like an RPG, because you couldn't kill it dead enough quick enough often enough with a projectile firing weapon you could carry, hold, and fire. Shoulder weapons of any size on such a beast would be considered folly for the insane.

Still, it'd be excitement, wouldn't it!

Wes

Wes,

But, but, that just wouldn't be sporting! You can't eliminate all the danger from dangerous game!

Wes,
A guy can fantasize about some real hunting can't he? I would go for the brainstem at the foramen magnum, where the c-spine meets the skull. It would have to be a quartering shot from behind, just run up and count coup on that thunder lizard.

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Good huntin' and shootin',
RAB

I guess everyone forms a mental picture of what hunting something like this would be like.

Mine is something like this:

We tracked it into a thicket. It's nearby, we know. A whiff of wind, twig snap, whatever, and then, suddenly, 75 feet to our left...

16,000 lbs of fury is awoken from a nap, it's already got 2 steps when we can see its head, now it's 30 feet away and 20 feet in the air, or under 2 steps, 3/4 second, looking down, dipping the head, moving unnervingly fast, crashing over and through dense brush like it wasn't there. Preparing to employ those great teeth. Head the size of a VW, Brain the size of a walnut, tough enough to survive battles with its own kind, it sees nothing but us.

Under these conditions, what would we consider an adequate stopping weapon? Adequate meaning that this kind of charge is fairly typical and the PH plans to keep being a PH for a while longer. Rember, under 3/4 second, rapidly moving target, intervening brush. Can a 25 pound .50 BMG be employed quickly and accurately enough? Will the .60 cal stopping rifle have any effect on the primitive nervous system, given the unlikelyhood of hitting a walnut through all that bone? Will those big bones break, or do we just put a hole in one? Is it likely that shock will end things before we're lunch? Or, do we back ourselves up with something we KNOW will end things there and then?

Hmmm, maybe we hunt these things at long range, sniping them with a .50BMG, 20mm, or whatever, but my imagination thinks close up is the way to go

Maybe it's about one's attitude towards life?

Wes

The spine would definitely be the target for a stop, preferably the upper portion. Dinosaurs had a well distributed nervous system and you might be able to put him down by hitting the nerve bundle over the hips, but I'd want to shut down the vital functions.

Its worth noting that a T-Rex or a sauropod had vastly stronger bone structures than does an elephant. After all, a T-Rex weighs as much as two elephants and can actually run (at least 35 mph, maybe 50+). Its built to sprint and absorb the shock loads of its own 8 ton bulk and to engage in fierce struggles with 30 to 80 ton prey animals.

I'm thinking that the best monolithic solids money can buy (maybe heat treated beryllium copper) weighing at least 700 grains and fired at 2400+ fps from a weapon of .50 caliber or larger is the minimum. You'd need a LOT of penetration plus bone shattering impact. And plenty of good luck!!!

Now what would be more sporting and a lot more exciting is to sneak up close and put one through the heart/lung area, then try to remain undetected. Being large and probably warm blooded a T-Rex might succumb as quickly as our (comparably large) game animals to such a shot. Maybe a gigantic X-Bullet for that first shot...?

Well sauropods. Who cares how tough their bones are.There is no way you would get me anywhere near any of the larger sauropod species on foot weighing up to 12 times as much as an elephant.
140,000lbs animal with a 700 nitro...not even close!!!!
A jeep mounted 50 BMG roaring across the plain after a herd of brontos. Now that sounds like Aussie hunting at its best

T.Rex,Deinocherium etc.
Different category.Vital shot, nerve shot/hip shot fine.

What about a charge?
What does the P.H carry for back up?

Heart lung shots don't even stop 1500lb crappy buffalo in time from what I have learnt here.
15,000 T .REX I think the client would be doing his shooting from the hatch of an armoured vehicle, ready to close the lid IF anything went wrong

Even the great mammals make our big game like midgets.
36,000 lb hornless rhino baluchetherium
4000 lb armadillo with club like tail-glyptodont.
15ft tall ground sloth.
Megaceros, with the antler span of a small plane (joke but...)
Homotherium, huge biting cat with arms like a gorilla.
etc. etc.

And our hairy little forefathers got to take these things on(and defend themselves) with nothing but spears, teamwork, rocks and well dug traps in some cases.

The good old days.

Karl.

[This message has been edited by Karl (edited 06-17-2001).]

You guys have covered the sport hunting well. How about the cull hunts and control work at Jurassic Park? I would suggest the A-10 Warthog as air support and spotter, with its 30 mm Vulcan cannon possibly serving as the primary attack weapon, plus laser guided bombs and rockets, if the tanks on the ground got overwhelmed. The bazooka type weapons like the LAWS and its successors might be the way to go for the sport hunter on foot.

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Good huntin' and shootin',
RAB

Shame on you Harald... being a mech engineer you should understand that a beryllium copper solid would produce a very high health hazard to the shooter.

RAB
Thanks for the page refs
I worked the BSI out on an excel worksheet most of the figures I got matched yours but some were different.

CAL GRAINS FPS SD BSI
0.375 300 2450 304.8 100
0.416 400 2750 330.2 180
0.505 600 2325 336.1 282
0.505 700 2260 392.1 373
0.50 535 2300 305.7 224
0.50 570 2150 325.7 238
0.51 600 2470 329.5 297
0.577 750 2460 321.8 408
0.585 750 2360 313.1 386
0.70 1000 2000 291.5 486

Well I think a an RPG would really have to be min cal. for a dino, or maybe one of those jeeps from WWII with the quad mounted 50cal machine guns.

BBS,
Looks like you have the hang of it. The minor differences may come from conventions of rounding. I always round to three decimal places with the sectional density term before doing the calculation, and keep the final product to three significant digits. The calibers and the bullet weights are the data that limit the BSI to 3 significant figures.

Also you have listed two loads as simply "0.50" caliber. You need to check whether you meant .505 or .510.

You might want to check the "basis" T.rex load of .585cal, 2447fps, 750grains, and SD = .313 >>>> BSI = 400.

If you look at the table under the FAQS section you will notice that several of the larger bore BSI values are wrong. I did not post these. Nonetheless, they are in the ballpark and serve to illustrate the concept.
There is a problem with hypnotization by numbers when mere mortals do the compilations.

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Good huntin' and shootin',
RAB

"Always shoot in a well ventilated area."

"What about a charge?
What does the P.H carry for back up?"

A fast extraction harness for the helicopter!

RAB
Once I put in the right cal - the figures matched. I worked it out with 8 decimal places.
Thanks for the info

Guns don't kill people - people kill people.