I wonder if a neck shot would be more lethal than a chest shot. Take out major arteries to the brain, or the spinal cord, or trachea, it will go down.
I’m not a hunter, but I have spent a lot of time in Africa and know and have my own ideas about firearms. 
Volume of fire can make up for a lot.
How many rounds in your magazine for Big 5 rifles? (What were your guides carrying in case you missed?)
I think a 12-ga with a long mag loaded with newer specialty slugs = a lot more lead in the target. 7+1 pump slugs vs 4 shots from a bolt action elephant gun.
Is the t-rex charging?
The actual gun filmed is indeed an 8-gauge, though I don’t know if “in story” it’s supposed to be bigger.
I AM a hunter. Hunting dangerous game means counting on one shot. As often as not, that’s what you get, and no more.
Professional hunters commonly carry double rifles, predominantly to allow them to get a second shot almost instantaneously with very little re-acquisition of the target. This is still the case and has ever been so. Close to a cape, or really anything that big, you don’t take chances. A double also reduces recoil, because the extra mass of the rifle will counter the mass of the projectile better. That’s why the 4 bore nitro is such a strange choice, and why I take what templar says with about a pound of salt; you can swing around a 577 or a 700 nitro fairly well, but any 4 bore(nitro) that was heavy enough to prevent it’s recoil from being fatal would be impossible to swing around adequately to hit a fast moving animal (They were designed to shoot elephants that were mostly standing still)
I had backs with me all the time, none of the guides were armed but our group took turns backing. I would not hunt with backs whose nerve and shooting skills I didn’t trust.
So, how about if we shoot it with fifty million BB’s?
Penetration and shock damage to vital organs, or severe damage to the nervous system is what matters. Everything else is throwing spitballs at Gojira
You mean more lead on the ground. A 12 gauge slug would bounce off the skin of a trex. A 12 gauge slug will bounce off the ribcage of a cape buffalo. there isn’t enough power to do any harm, and to get the 12 gauge slug to be powerful enough it would turn the firearm into a grenade. If you beef it up to handle the power you have- a big game rifle of large caliber.
Cool, I always wanted the “dead-least” pistol ever.
You call that a gun? That’s not a gun. Thisis a gun.
Now who wants some lizard chili?
THAT bad boy looks like it would take out a T-Rex!
That’s a WW2-era 20mm antimaterial gun- “gun” as in man-portable artillery piece. God help you if your first shot misses, you’ll never line up a second.
As I said in one of the previous threads, you don’t want to have to hose your target down with lead as it’s charging you, but you do want at least a second shot right away. Pretty much Billy Rubin’s advice.
But it’s the “dead-least”! Who wouldn’t want the “dead-least”?
Hey, when you pack an 18-shooter, people tend to overlook spelling errors!
Actually standing up to 40 feet tall and having a head larger than some automobiles today, I think in a clear area you could get quite a few shots off since you could see him clearly several miles away and some of the guns were talking about have very long range. The column doesn’t delve into questions like that but chances are you would get way more than one shot in this hypothetical exercise. If you used a little common sense and started your attack from atop a high hill with a long distance for him to run you could make up for lack of stopping power with unlimited ammo and a lot of enthusiasm.
More importantly, how much LSD does it take for a T-Rex to attack you from a few miles away while you’re on a hill anyway?
How about a Tommy gun loaded with dum-dums?
No, standard .50 cartridges don’t produce enough energy. I suppose a tommygun could eventually do enough damage to cause a T rex to bleed out, but you’d be spaghetti sauce before it actually fell down.
The .50 BMG far outclasses most any other commonly available cartridge (except, perhaps, the “California” round developed by Barrett). It certainly leaves the .460 Weatherby, mentioned in the article, in the dust.
As for the 4-bore “Nitro” mentioned, I’m not convinced such a thing ever existed. There were certainly 2- and 4-bore blackpowder cartridges, and they were pretty impressive, but they still fired big, slowish round balls or stubby conicals. If any were loaded with smokeless powder, I’d expect performance no better than with BP, and possibly worse.
In terms of kinetic energy at the muzzle (for what little that’s worth), .50 BMG is comparable to a 2-bore elephant gun. That’s assuming that the 2-bore muzzle velocities and bullet weights I’ve seen published are accurate (I’m skeptical).
I’d still prefer the faster, more streamlined bullet, thanks all the same.
In fact, if we’re going to go exotic, why not just lug an M18 recoilless rifle? As a bonus, if anything is trying to sneak up from behind, you can take it out simultaneously. 
Whoops, were we talking Thompson SMGs? Those were mostly chambered in .45 ACP and, yeah, not with any large, dangerous game, living or long extinct.
Not only do they exist, but many are still in use. I’ve never shot a 4 bore but I have shot 8 bore in black powder and nitro. There is an appreciable difference, let me assure you.
the 50 BMG has a lot of reach out and touch someone, hence it’s use in long distance sniper work. At those long distances, though, the energy required to penetrate the hide and ribcage of a large predator drops off dramatically. Still fine for humans, not so good on trex. At short distances, the 50 BMG is not a good dangerous game round. No spire point projectile is going to be a good big game cartridge anyway, as time and experience has proven that the solid bronze or brass projectiles with a wide meplat are required to cause sufficient trauma for a quick kill.
An excellent recipe for being dead. In many parts of Africa you are regulated as to what ammunition you can use, the alternative being a lot of would be big game hunters relying on their trusty semiautomatics and large bore military rifles (Designed to kill 6’ tall thin skinned bipeds) being sent home in body bags.
Yeah, my mistake.
Be that as it may, you’re not going to get a 1/4-pound ball moving very fast without damaging either yourself or the gun (or rifle, as the case may be).
BTW, if you have links to specifications for monster-bore nitro cartridges, I’d love to have them.
That’s a matter of choosing the right bullet. I never suggested that GI Ball, or even AP, would be appropriate, though the HE penetrators issued to snipers for shooting folks behind walls might be worth a look.
There’s a lot of territory to explore between “spire point” and “flying pumpkin.”
Of course, knowing as little about theropod anatomy as we do, it’s all wild speculation at best. Frankly, between my ignorance and the critter’s size, I’m going to want something that reliably gets inside its chest and explodes (not expand, not fragment, but explode) – just to be on the safe side. Nothing on the (Western) civilian market will do that.
Anything larger than .303 would be unsporting, wouldn’t you know, old chap.
(I’ve no wish to pick on anyone in particular. The American alternative would be, “My .30-06’ll kill anything, dagnabbit.”)
I have very little experience hunting dinosaurs (ok, ok or anything else for that matter), so apologies for my ignorance… But if I was going up against 42 foot long critter with 12 inch teeth, I’d want some armor between me and it. Tanks are fine, but I’d also want mobile firepower. Would the M113 armored personnel carrier serve these purposes? It typically packs a .50 caliber Browning machine gun. The gun reportedly is used against lightly armored autos and boats, as well as low flying aircraft. It’s mounted on a turret and looks movable. And if Dino gets uncomfortably close, just duck into the M113 and wait for him to bleed out. Antitank weapons are also possible. Or is there a better setup? True, a jet aircraft, battleship or bomb shelter would probably be safer, though they would afford fewer sightseeing opportunities.
The column does say:
Essentially there are a million ways to kill a T. rex. Grenades, cyanide gas bombs, flamethrowers, an A-10 Warthog, the USS Missouri…we wanted to try to limit it to weapons which could be legally carried and used by an erstwhile Elmer J. Fudd without requiring military training or other unusual munitions.