That makes sense. The line is drawn between anything used to hunt game in the real world, and anything not–eg, a recoilless rifle.
Also, “erstwhile” means “former.” I think you wanted “would-be” or “sometime.”
ETA: It just occurred to me that helicopters are sometimes used to hunt game; that would make the whole thing rather easier. It’s harder to shoot from a moving platform, but there’s no chance the T. Rex is going to close with you while you reload.
The 1/4 pound ball doesn’t have to move very fast to do a good deal of damage. Which would you rather be hit by, a nerf ball thrown at 50 mph, or a shotput thrown at 50 mph?
There is some discussion of this in many of the books about shooting dangerous game, but the reason there isn’t a lot of published data is that large caliber bore guns are almost invariably bespoke, and are loaded to the specifications of the owner. If you want to know the load data, you break open the rifle and look at the engraving on the water table. On this page you can see an example of this about halfway down.
Indeed, it is a matter of choosing the correct bullet and the correct firearm. I’ve shot a lot of 50 bmg, in single shot, bolt action, semi and full auto, and not one of them was meant to be carried by a man into a hunting situation and shoulder fired at a moving target. If you’re talking about sniping, from any distance by the time the projectile from a 50 cal arrives at the trex it will have lost enough of its oomph that it will be of very little use. The 50 bmg was designed, as I have said before, to take down a soft skinned biped around 6’ tall; pressing it into service for big game hunting is impractical. You specifically stated
Streamlining is something that specifically refers to spire point bullets, no wide meplat bullet can be considered “Streamlined”, and streamlined bullets are never indicated for dangerous game.
This is also impractical and unnecesary. Exploding projectiles were experimented with in big game hunting years ago, and discarded as impractical and potentially downright dangerous. Read “After Big Game in Central Africa” by Edoard Foa for a description of the explosive projectile and how it worked (or didn’t, for that matter)
The OP specifically refers to the ability of an individual to take down a large predator with a handgun, and the discussion has centered around the weapons that might be practically carried to do so; the 50 bmg does not fit that bill, and won’t. Bore rifles might, but would be ridiculously heavy to carry, almost as bad as a 50 cal but at least possible to swing around in a dangerous situation. Famously Col. Richard Meinertzhagen began elephant hunting with large bore rifles and switched to light doubles simply because of the horrendously punishing recoil. As has been stated a fast boltie or a medium double in one of the large calibers like 577 trex or 600 overkill would be the most suitable, especially if equipped with a good solid projectile with a wide meplat and a good sectional density.
While this will always only be a theoretical exercise there are plenty of things we know. In B.H Newman’s book “Stance and gait in the flesh-eating dinosaur Tyrannosaurus” he posits that the skeletal structure is such that the animal would move with it’s spine nearly horizontal, and one headed toward you would present a very small vital target indeed; you’d have to hit an area the size of a dinner plate, IF the rex wasn’t holding it’s head down.
A side shot would present a better target, assuming you could get to the side; the ribs (From the fossil record) were a relatively thin framework, unlike, say, ungulates in which the ribs often nearly touch. A heavy, short projectile with a wide flat nose (Meplat) at moderate veliocities is the best fit.
What I think most folks are forgetting is, that once you’ve bagged this T-Rex on the bike path, you are going to want to taxidermy this puppy. Sure, it is all well and good that you’ve managed to save your own skin, but dude, you’ve probably just bagged the one and only surviving T-Rex in the world, and you are going to want to be able to at least save the head for your den’s wall! Who’s going to believe you if you don’t have the proof. Let’s limit the amount of collateral damage to the T-Rex by not going with the RPGs or too large a caliber firearm.
The point of this thread is that too large a caliber is unlikely to be a problem. 
I guess he’d be erstwhile after meeting the T. rex…
The comparison is specious. A slightly, but only slightly, better comparison would be between a 16-lb shot put at 50 mph versus, say, a 12-oz Nerf football at 300 mph.
That assumes a 1/4-lb projectile at 1400 fps which, I admit, is conservative. I’ve seen references to 2-bores making ~1500 fps with a heavier bullet, so 1800 fps with a 4-bore (rough energetic parity against a 650-grain .50 BMG load) might not be unreasonable. Then, you’re talking about a 231 mph football.
It’s still silly. You simply can’t compare a squishy low-density Nerf ball to an iron shot put. Make it a 12-oz plumb bob moving toward you pointy end first at 200-300 mph and you get a little closer to the mark, so to speak.
The only reference to a 4-bore “nitro” cartridge I could find there was someone wondering when someone might make such a thing.
That’s the second time you’ve made that rather bizarre claim.
Sure, “take down” a soft-skinned biped…a long way away…after passing through light armor, aircraft fuselages, etc.
The notion of specifically and deliberately shooting people with the .50 BMG is recent, and it’s only because the rifle/ammo combinations are so accurate (and potent) at very long ranges. Even at 2500 yards or so, the terminal results are…impressive.
I don’t believe I ever advocated the use of heavy .50 BMG target rifles afield. My original post was purely technical and based on a misunderstanding at that.
Now, could a relatively lightweight .50 BMG sporting rifle be devised? Probably, though I’d expect it to kick like an SOB, even with a good brake (and accuracy is anyone’s guess). How would it perform compared a big-bore blackpowder gun? That’s open to debate, and it’s a debate I’ve neither the resources, nor the interest, to pursue.
The latest info is T Rex was about 30 percent heavier than was previously thought.
We need a bigger gun.
Elephant and cape buffalo regularly manage to kill experienced hunters armed with (and backed up by) some of the most powerful big game rifles available.
But we’re not talking about large peaceful herbivores whose idea of a good day is rich grazing near clean water with no predators about (humans do qualify).
We’re talking about a truly massive carnivorous dinosaur, twice the height of a bull elephant and seven times the weight of a cape buffalo, whose idea of a good day is to run down, kill and eat meat (humans do qualify).
Saying a conventional big game rifle is sufficient for T. Rex is like saying your 30-30 worked great on that 10 point buck, it should handle a black rhino just fine.
Carry whatever you feel is appropriate for betting your life on being able to kill (not annoy, irritate, aggravate, anger or enrage) an animal that could eat you, your gun bearer and most of your guide in a single bite.
If my life depended on killing a T. Rex with just civilian firepower, the 800gr 50BMG load (at about twice the muzzle energy of the 4-Bore and 10 times the effective range) would be my first choice.
In the quasi-military category, I agree with eastcheap on the effectiveness of explosive rounds and point out that Norwegian high explosive 50BMG rounds (Raufoss Mk 211) are rare and expensive but they show up for sale here from time to time.
The development of several lightweight, man portable anti-material/anti-personnel 50BMG sniper rifles in the past few decades, ranging from the 29 lb semi-automatic 10 shot Barrett M82A1 to the 13.5 lb bolt action 5 shot Anzio (all with about the recoil of a 12 Ga. shotgun firing slugs), limits any serious consideration of a 22 lb 4-Bore (usually carried as a last resort ‘reserve’ gun due to very limited range, marginal accuracy and 200 foot pounds of recoil!) to only the most dedicated masochists.
Possibly the biggest lack of reading comprehension I have witnessed here in a long time. let me reprint the section in question that you may understand.
"If you want to know the load data, you break open the rifle and look at the engraving on the water table. On this page you can see an example of this about halfway down. " The point of the link was a demonstration of how bespoke rifles carried their load data with them, and it was not commonly published. Do try and keep up.
“That’s the second time you’ve made that rather bizarre claim.”
No. It’s the second time I have repeated a demonstrable fact. The 50 BMG, based on a scaled up 30-06 round, is predominantly antipersonnel, and was designed by John Browning as an antipersonnel round. The armor piercing ammunition was developed later, the initial and still primary use for the round was the Ma Deuce (m2hb) which is an antipersonnel weapon. In every event, the target was a human being, and not a large carnivore. End of that question.
I have no real interest in the topic at hand, but was that really necessary?
Curious engineering, designing a huge, heavy anti-personnel gun and round that can kill soldiers stacked four deep and accurately reach out 1.2 miles - far past the range where human beings can be distinguished by eye (50BMG’s and telescopic sights first got together in Korea).
That doesn’t sound like the John Moses Browning I’m familiar with, asked for an anti-personnel machine gun I’d think he’d be more likely to design a BAR or an M1919.
Do you have any citations to support what appears to be a minority opinion?
“Using a round originally designed by Winchester, the .50BMG round was designed as a response to the German 13mm antitank rifles of World War I and employed in a redesigned and scaled-up M1917 Browning .30 cal machine gun. It was quickly adapted to the anti-aircraft role.”
http://50bmgsupply.com/
“The ammo round was conceptualized during WWI by John Browning in response to a requirement for an anti-aircraft weapon.”
“The 50 caliber Browning Machine Gun (BMG) was developed in 1917 from John Browning’s design. Its intended use was as an anti-aircraft battery and anti-tank weapon. It was not intended to be used as an anti-personnel weapon.”
While 50BMG’s anti-aircraft role has been vastly reduced by jet plane speeds, the development of AP, SLAP and HEIAP rounds to counter continuing advances in mobile armor have kept it a popular anti-material/light anti-tank round in addition to utterly demoralizing infantry with it’s nowhere-to-hide overkill.
I would think at the very least a standard .50 cal. would render the animal unconcious if struck in the head area. At 150 yds using tracers you may be very lucky, but a .50 cal round at that range is like getting hit with a ton of lead the size of your thumb. An impact of that nature would most assuredly cause damage enough to at least stop the animal or seriously impair function. If it were me in that situation it might be worth messing my britches to lay out that beast!
Zombie thread revived because I found something new to say: I’d said earlier that powerful as the .50 BMG round is, I don’t think it’s “wieldable” as a game rifle. I recently happend upon a Wiki article on what may be the most powerful game round currently available: the .460 Weatherby Magnum.
A round too powerful for anything smaller than a Cape Buffalo? Sounds like a winner.