So I've been working my way through John Ringo's Black Tide Rising series as of late. I'm partway into book 2 right now. If you haven't read this series and like ZPOC fiction give this one a whirl it's good.Warning however, there are some spoilers ahead.
To 1st understand this discussion you need to understand the context of Black Tide Rising. In this series the Smith family gets word from a relative that a major, world ending event is imminent and that they need to "bug out". In this case the "bug out" is done via the sea in a 45 foot sailboat. The event is a Zombie Apocalypse. The zombies aren't dead they are infected with a highly modified Rabies virus and thus still living beings not the typical walking dead we see in so many tv shows and movies.
The Smith family is ofcourse an armed family, they are a family of survivalists. Their firearms consists of hand guns in .45 acp, AKs in 7.62x39, and Saiga shotguns in 12 ga.
To make a very long story at this point short, one of the protagonists is working with rescued Marines to clear ships at sea of infected. In doing so she complains their M4s, which were salvaged off a US coast guard cutter, are "barbie guns" and they take several shots to put down a zombie where as the shotgun she normally uses takes 1 or 2 shots instead. The book disparages the 5.56x45 and puts forth the notion that the 12 ga buckshot ammo is superior in stopping power.
John Ringo is entirely correct here. He's also completely wrong. This is where CONTEXT is so incredibly important. One or two seemingly tiny variables completely changes the outcome.
Its all about the ammo, and the condition of the target here, that is creating this zombies not being stopped situation.
The M4s, and their ammo, is being sourced from a military vessel, a coast guard cutter. In the early 1980s the US Army, and by extension the other branches adopted a new version of the M16 and new ammo. The old Vietnam era rifles were regulated to reserve and Guard use as was their older ammo. You see the new ammo only worked correctly in the new rifle, where as the old ammo worked in both the old model and the new one. This new ammo is called M855 and the old ammo M193. The M855 round uses a 62 grain bullet with a steel insert in its tip to aid in penetration of think skinned vehicles and infantry helmets. The old M193 round used a simple copper jackected 55 grn FMJ. When the US Army adopted the M4, they stuck with this newer M855 cartridge.
Ok so you've gotten a breif history of small arms of the US army what does this have to do with not stopping Zombies?
Bullets do one of four things when they strike a fleshy target. They bore a hole straight through and this is commonly called "ice picking". The bullet, while it does hole the target, does very little damage to it.
The second thing a bullet may do, if its of a type that does so like a hollow point or soft nosed bullet is that it expands. This expansion inside the target does significant damage, sheds energy, and reduces the chances of over penetration. Common hunting bullets and defensive pistol bullets are bullets designed to expand.
The third thing a bullet may do is yaw. Yawing is when the bullet looses stability inside the target causing it to change direction and or flip end over end. Yawing can do significant damage to the target like an expanding bullet but without the expansion. Typically this yawing only occurs with rifle bullets.
Lastly the bullet may fragment. Fragmentation can produce terrible wounds. When the bullet fragments it breaks up sending small bits in different directions through the target and sheds enormous amount of its energy in doing so.
The old M193 bullet is a fragmenting bullet. At velocities above 2700 fps it yaws and then breaks up inside targets its shot into with regularity. The original M16 had a 20 inch barrel and M193 had a muzzle velocity of 3250 FPS. This gave the old M16 a fragmentation range of around 150-200 yards.
The newer M855 is a slower bullet. It travels at around 3100 fps for the newer model M16 and about 2900 fps from the M4 used in Ringo's book. This is significantly slower than the old M193 and the bullet is much longer making it more likely to not yaw.
When the M855 bullet does finally yaw and fragment, its late to the party. The distance between the entry point of the bullet and the spot in which it begins either yawing or fragmenting is called the neck length of the wound. The neck length of M855 can be as much as 8 inches.
So you're two months into the ZPOC. Your average fat american is now a skinny raving biting zombie. You've got a short barreled carbine which reduces the bullets velocity combined with a bullet not designed to yaw but to penetrate.
You're gonna have a bad time. John Ringo is right about "the barbie gun".
But I'm not in the service and likely you the reader aren't either. I get to pick whatever bullet I want for my AR-15 and I get to pick its barrel length. This is why Ringo is wrong about "the barbie gun". The 77 grn Black Hills 5,56 ammo fragments violently with little to no neck length. The Hornady 75 grn BTHP match has a short 1-2 inch neck before it too fragments violently. Even M193 in this instance is going to be pretty effective. It might not frag every time but it will fragment frequently.
John Ringo has likely never bugged out once in in life. Most people who write about it have never done it. I've done it 3 or 4 times. FOR REAL. Not practice bug outs. We call them Hurricane Evacuations but its the same thing. Its a balancing act between space, weight, and do you need it? Twelve ga shotgun ammo is very bulky compared to 5.56. Twelve hundred rounds of 5.56 will fit in a 50 cal usgi ammo can while just 375 2.75 inch 12 ga shells fit. Nearly 700 rounds of 5.56 fits in a 30 cal ammo can but only 175 12 ga shells.
5.56 mm simply consumes much less space than 12 ga shot gun ammo. In the confined spaces of a boat a short 5.56 mm carbine or AR pistol is going to be superior to the shotgun. Combined with lower recoil and high ammunition capacity it beats the shotgun. However it has another attribute the shogun doesn't have: Range.
On land, or simply a large boast like a ship, a shotgun with buckshot is good for a maximum range of around 50 yards. The carbine's effective range is up to 200. Notice I said "effective". You can hit a target much further but past 200 yards your bullet will be ice picking the target.
To conclude this discussion, John Ringo was right in his assessment of the "barbie gun" M4 but its due to the poor bullet choices the military and NATO made back in the early 1980s. Modern fragmenting 5.56 mm changes the game completely.
My advice to writers is this: Do your research. Nothing is more infuriating to a gun guy than reading horrifically inaccurate or plain wrong information in some novelists works. I can't read Lee Child's work because the firearms writing is so hopelessly terrible.
