ElPatron said:
FMJs, due to their high speed, fragment the copper jacket and tumble, creating a bigger temporary cavity than frangible rounds.
Under ideal circumstances, yes, the FMJ round will tumble and fragment, though any attempt to get the round to do so
on purpose is a violation of the Hague Conventions and, by extension, illegal to use in a weapon of war.
And when we start discussing temporary cavities, hydrostatic shock, and all the other nifty little poorly-understood concepts that surround the debated topic of "stopping power", we're venturing into speculation.
FMJ rounds tend to overpenetrate. This much is difficult to dispute. Overpenetration results in less energy transmitted to the target. This is also difficult to dispute.
ElPatron said:
What I said was that the round was able to knock him down by simple transfer of forward momentum onto his arm, creating rotation.
What you said was this:
He caught one in his elbow, he said it was like he got hammered by a huge mass. He spun twice and hit the ground with the sheer force of the impact.
Don't correct yourself after the fact and claim that your statement said something it did not.
ElPatron said:
I dare you to take a 5.56x45mm on your elbow and not rotating, even if you have been preparing yourself for days. Of course, this is only hypothetical, because I know for a fact you can't "prepare" yourself for a hit.
Technically you can prepare yourself just about anything. It's why you'll see people doing vest tests that can take the hit and respond, and others who are shot unaware with the
exact same round, under the exact same circumstances, get knocked down.
Hell, it's the fundamental principle behind all those annoying "energy bracelets with the power of
magnets!" tests you see being pushed on television in the wee hours of morning. Running someone through the same set of tests a second time will invariably result in a better performance, whether they think they're prepared for it nor not. They know what's coming, and they know what to do to prevent themselves from getting pulled off balance, pushed over, or whatever tests the shill trying to sell you a couple cheap magnets attached to a rubber wristband is putting them through.
ElPatron said:
Plus, the buttstock of a weapon has a bigger surface area than a spitzer bullet. I don't know what you're talking about.
Obviously nobody is putting sharp pointy spikes on the buttstocks. As for time, however, that much is self-evident; a bullet is accelerating as it travels down the barrel, because ideally the powder charge is calibrated that way. If the bullet is
not accelerating, then the barrel is too long, a problem that they had in early black powder cannon design.
So a 5.56 out of an M-16 has 20" worth of time, so to speak, to accelerate, and if we're using a well-designed frangible round, perhaps as few as 4" to shed that accumulated energy.
Oh, and assuming that the rifle is properly tucked in, the man and gun form a system. Yes, you can have some measure of recoil absorption by the weapon, but if the butt is in contact with the shoulder... not much. The rifle is just adding another few pounds to the system as a whole, meaning that the man/rifle system is pushed back a little less far than he would be otherwise.
ElPatron said:
Yes it can.
Do the math, if you're so inclined.
A 340 grain (22 gram) .44 Magnum slug moving at 1,325 ft/s (or 404 m/s) carries about 1795 joules of kinetic energy. (.5*.022)*404^2=1795
A 77 grain (5 gram) .223 Remington slug moving at 2,750 ft/s (or 840 m/s) carries about 1764 joules of kinetic energy. (.5*.005)*840^2=1764
Basic physics.
Neither round is the most powerful one that can be fired from the respective weapons, and
on average the .223 rounds carry more energy, but not by a lot, typically around 10% or so.
.50 AE rounds, however, hit harder than .223 almost universally. .454 Casull, .460 and .500 S&W Magnum; these rounds all carry vastly more energy than any .223 round in existence.
And, technically, they're pistol ammo. If you've got hands like canned hams and forearms like a gorilla, at least.