SMGs and assault rifles are what?

[Sea Skimmer]

This is usually not a big issue, but can be severely detrimental in such weapons as the M4, where the 5.56x45 cannot be trusted to reliably fragment under all conditions.

You mean penetrate or tumble?

No he means fragment. Fired from a 20 inch barrel 5.56x45mm ball ammuntion should fragment out to about 200 meters, but from the 14.5 inch barrel of an M4 it will only do so out to about 50 meters.

Note that one does not base carbines off of full-size cartridges like the 7.62x51 NATO or 7.62x54R Warsaw Pact rounds fired by battle rifles such as the HK G3, M14, FN FAL, and so on. Carbines are, to my knowledge, based exclusively on assault rifles.

Carbines predate assault rifles by a great many decades, as do intermediate sized rifles like the later versions of the Lee Enfield and the Mauser 98K which where designed to fill both roles with a single weapon.

I think you'd be hard pressed to find a 9 mm or .45 SMG that will reliably penetrate body armor without multiple hits even at relatively close range.

Depends on the armor, there are certainly a couple 9mm rounds which will pierce Level II armor at close range reliably. But you won't find much anything in that caliber which can tackle the Level III armor used by military forces.

[Illuminatus Primus]

No he means fragment. Fired from a 20 inch barrel 5.56x45mm ball ammuntion should fragment out to about 200 meters, but from the 14.5 inch barrel of an M4 it will only do so out to about 50 meters.

5.56 NATO fragments on impact? I thought the Belgian round (SS109?) was designed for penetration, and the one before that was designed to tumble-end-on-end on impact? Aren't fragmenting bullets prohibited by Geneva?

Carbines predate assault rifles by a great many decades, as do intermediate sized rifles like the later versions of the Lee Enfield and the Mauser 98K which where designed to fill both roles with a single weapon.

So what's the correct term for carbine versions of assault rifles? Assault carbines? Or is it just assumed since we don't see any other carbines since WW2?

Depends on the armor, there are certainly a couple 9mm rounds which will pierce Level II armor at close range reliably. But you won't find much anything in that caliber which can tackle the Level III armor used by military forces.

Ouch. Terrorists/insurgents/whatever get ahold of some military armor and hole-up in some building you'd basically be stuck going room to room with M4s, no?

[YT300000]

If you want to be a terminology whore then you should understand the fact that when you really get down to it none of these classifications are anything more then terms of conveiance and from a technical standpoint only bolt action and automatic rifles exist among modern military arms.

True. I guess I'm a little irrationally inflammatory on this topic. The Machine Pistol (hell, all German-derived classes) classification used to drive me insane (no idea why), and I just used SMG for it.

[Sea Skimmer]

5.56 NATO fragments on impact?

5.56x45mm NATO ball ammunition certainly fragments as it passes through a body at high velocity. That lets it do rather interesting things like tear off arms at close range. Though that doesn't happen too often.

I thought the Belgian round (SS109?) was designed for penetration, and the one before that was designed to tumble-end-on-end on impact?

SS109 is a Semi Armor Piercing Bullet. It has a hard steel nose and an aluminum core behind that. In theory the two should break apart and tumble on impact, allowing it to both pierce body armor and create a wide damage path. In practice the round often sails clear through a target without separating. It also does fragment quite a bit in some instances. However many bullets have the potential to do that. The orginal ball ammuntion was meant to and did tumble. But high velocity tumbling tended to cause it to breakup and fragment, often instantly.

Aren't fragmenting bullets prohibited by Geneva?

Bullets specifically designed to do so are and more then once the likes of Jane Fonda have called 5.56mm weapons illegal. However the ruling from actual military courts has essentially been that only bullets designed specifically to fragment are banned by it. 5.56 only fragments as a result of hitting at extremely high velocity, ball round is a plain old FMJ bullet. So its not banned, for among other reasons that given a sufficiently high impact velocity any bullet will fragment on impact.

So what's the correct term for carbine versions of assault rifles? Assault carbines? Or is it just assumed since we don't see any other carbines since WW2?

They just get called carbines. The people who think this stuff up kind of expect that you won't be in a total information vacuum.

Ouch. Terrorists/insurgents/whatever get ahold of some military armor and hole-up in some building you'd basically be stuck going room to room with M4s, no?

Basically. Though if you have terrorist of that skill and resources to fight, then you'll also hopefully have a counter terrorist organization of the "three round burst to every head" type. But then, they already make helmets, which offer level IV protection, and I'm aware of Level III facemasks. Level IV body armor is also around. Level IV BTW, by the Lasco standards is sufficient to stop a full sized 7.62x51mm bullet at close range. Level V is 5.56x45mm at close range from an M16, I don't think personal armor of that standard exists, though they do make solid metal shields that have that kind of protection.

However we probably don't have much to fear from that sort of scenario, wearing all of that protective gear is heavy and hot as fuck and very constricting to vision and movement. Normally only bomb disposal crews use such stuff. Facemasks are espically unpopular, since they distort vision, heat up your face and make such simple things as scratching your nose difficult. Holding a bunch of hostages for hours on end while in such suits would be a mild living hell.

Terrorist also aren't exactly going to blend in while approaching the target in fifty odd pounds of visabul armor. In addition, getting anything beyond level II body armor, and sometimes even that is very hard in most parts of the world (most companies won't sell anything heavier to civilians) and is often illegal.

[Howedar]

I'd simply go with a rifle with a shorter barrel; none of your bullpup carbines have collapsible buttstocks; and some of the others like the Soviet AKS-74U simply have a side-folding skeleton stocking.

1. What does "usually" mean to you?
2. If you're going to nitpick how the butt collapses/folds/whatever then you are being rather silly.

Definitely a difference given the twist and balance of the current Belgian 5.56x45 round.

Addressed by SS.

You mean penetrate or tumble?

Addressed by SS.

The initial round of NATO rifles with the 7.62x51 round are still considered assault rifles, I believe. Although I have heard the M14 refered to as a "battle rifle."

Nope.

Oh, and H&K did make a carbine G3.

Yah, I was thinking in a more modern sense. If we want to be technical, we've had carbines for quite a long while, what with the dragoon versions of rifles and such.

I think you'd be hard pressed to find a 9 mm or .45 SMG that will reliably penetrate body armor without multiple hits even at relatively close range.

You will find that body armor is not commonplace among the enemies the US, UK, Russia, and so forth are fighting these days. You are correct to some extent but I saw no need to address this.

Carbines predate assault rifles by a great many decades, as do intermediate sized rifles like the later versions of the Lee Enfield and the Mauser 98K which where designed to fill both roles with a single weapon.

You are of course correct, but I didn't really want to muddy the waters that much when those asking the questions are unsure even of the difference between a carbine and a rifle.

[Slartibartfast]

Both can fire in semi auto and full auto. So, for us normal people, once and for all, what's the difference(s) between a sub-machine gun and an assault rifle?

The same difference between a single-shot pistol and a single-shot rifle.