A discussion of the semi-automatic firearm

[unixronin]

This is the continuation of a discussion from a comment thread in a previous post, wherein the question was asked "Why would someone need a semi-automatic firearm?"

To answer this, let's begin with a brief discussion of firearm action types in the broader sense.

When asked to divide firearms into types, most people think something like "pistol, rifle, shotgun."  But there are two more basic divisions:  breech-loader vs. muzzle-loader, and single-shot vs. repeater.  We'll skip the discussion of muzzle-loaders for now, since they aren't really germane to this discussion, and confine ourselves strictly to breech-loaders firing fixed metallic-cartridge ammunition.

Now, a single-shot firearm is one with which, after each and every shot, you must manually open the action, extract the empty case of the just-fired round, insert a new unfired round, and close the action before you can fire again.  The US Army's 1870s-vintage Trapdoor Springfield was a single-shot rifle.  So was the Martini-Henry rifle with which the British Army fought the Zulu War (and with which 129 Welsh Borderers broke a five-thousand man Zulu army at Rourke's Drift), and so was the Sharps buffalo rifle.  These days, single-shot hunting rifles such as the Ruger No.1 and the Thompson/Center Encore are still popular.  Olympic 50-meter pistols and most of the world's most expensive and accurate precision smallbore target rifles are also single-shot.

A repeater is, in principle, any firearm which carries more than one round of ammunition within it and has a mechanism for rapidly loading those additional rounds into the chamber ready to fire.  (For the moment, for the sake of simplicity, we'll simply class things like double-barrelled shotguns, double rifles and drillings and other combination guns as being multiple-barrel single-shot weapons.)

There are many types of repeating firearms.  A revolver is a repeater.  So is a lever-action carbine, a bolt-action rifle or pistol, a pump-action shotgun, a semi-automatic pistol or rifle, or a belt-fed machine gun.  (We'll discuss the differences between a semi-automatic and a machine gun in a minute.)  These all share one important feature that distinguishes them from single-shots: the capacity to have two or more rapid follow-up shots, without stopping to reload, should you need them.  That one difference from single-shots is far more significant than the differences between the different types of repeating actions.

Many people would like you to think that simply being semi-automatic inherently makes a firearm many times more deadly and turns it into a ravening fountain of death and destruction.  This, however, is simply not true.  It is true that a semi-automatic action performs the act of reloading the action faster, and with less disturbance of the shooter's firing position, than most other actions.

But wait, didn't I just say "most"?  Not "all"?  Did I really mean that?

Arguments still continue about which is better, the semi-automatic pistol or the revolver.  The revolver is less prone to jams during firing, will not suffer a stoppage if a round fails to fire, and does not have ejected brass flying or a heavy metal slide shuttling rapidly back and forth.  Both can be operated extremely fast by an expert.  I have a video of a speed-shooting exhibition by revolver expert Jerry Miculek, in which he first fires eight aimed shots on one target in one second, followed by eight shots on four targets in 1.04 seconds, followed by (with a different revolver) six shots, reload, and six shots more on the same target in 2.99 seconds.

Granted, Miculek is an extreme example.  But nevertheless, all of these repeating actions have one thing in common:  All of them can be cycled faster than the average shooter can actually aim in the first place.  None of them are to be underestimated.  The Boer War was fought with bolt-action rifles on the Boer side; every nation involved in the First World War fought it using bolt-action rifles; every nation involved in the Second World War used bolt-action rifles.  (Of all the nations involved in World War 2, only Germany, the US, and Russia fielded semi-automatic rifles during the war.  Of those, Germany developed them relatively late in the war and still issued bolt-action rifles to most troops, while Russia entered the war using mainly the bolt-action Mosin-Nagant M91-30 and began issuing the Tokarev SVT-40 only after 1940.  The United States primarily used the M1 Garand semi-automatic rifle, but some troops still carried the bolt-action M1903 Springfield.)  Lever-action rifles were ubiquitous in the post-Civil War American west, and are still used by hunters today to take game as large as moose.  There are purpose-designed semi-automatic hunting rifles, that differ functionally from such things as semi-auto civilian-market AK copies in only two regards:  smaller magazine capacity (usually four rounds or less, comparable to most bolt-action hunting rifles) and considerably greater power.  Essentially everything else is cosmetic.  The German arms firm Heckler und Koch sells, or used to sell, a semi-auto hunting rifle that was based on precisely the same action as their G-3 battle rifle (as well as the HK91, a semi-automatic G-3 for the civilian market).  Visibly, it has a traditional sporter-styled walnut stock instead of a military-styled stock; internally, the mechanism is identical except that the safety does not have a full-auto position.  Many other firearms manufacturers, both American and not, manufacture purpose-designed semi-automatic hunting rifles that look just like a "traditional" hunting rifle unless you look at the actual breech area of the rifle and know how to tell the difference.

There's another important thing that all of these action types have in common.  With each of them, each time you pull the trigger, the weapon goes BANG ... once.  Then nothing happens until you release the trigger, cycle the action if necessary, and pull the trigger again.  Granted, with a semi-auto, a moderately skilled shooter can fire two or possibly even three shots a second.  But a skilled rifleman with a lever-action rifle can also get off two shots a second, and the internal mechanism of the Winchester Model 12 shotgun was such that if you simply held the trigger back, it would fire as fast as you could slam the pump slide back and forth.  (First world war GI "doughboys" called it the Trench Broom.)  This characteristic was shared by the earlier Winchester Model 1897.

The TV news likes to deliberately muddy the issue by showing footage of rifles that, when the trigger is pulled, fire repeatedly until you release the trigger.  But this is something else altogether.  That is a fully automatic weapon, also known as a machine gun — and, unless you have a Federal Class III license and you've paid the transfer tax on the weapon, it's illegal for civilians to own in the US.  Showing footage of full-automatic weapons — machine guns — while talking about semi-automatic weapons is at best misinformation, if not a deliberate lie of omission.

There's an important point here that we have to consider, though.  All firearms recoil when fired.  That means before you can fire another effective shot, you've got to bring the sights back on target.  And that, at pretty much anything much beyond arms' length, takes anyone but an expert shooter from one to several seconds.  So that brings us to another common characteristic shared by all repeating firearms — all of them are capable of being cycled faster than most shooters can aim the next shot anyway.

Yes, with a semi-auto you can simply yank the trigger as fast as you possibly can.  Shooters call this technique "spray and pray" — because only through the agency of divine intervention or sheer dumb luck are any of your shots going to hit your target.  I once watched a yahoo with a HK91 empty a 20-round magazine at a one-gallon milk jug at a range of maybe twenty yards, pretty much as fast as he could pull the trigger, and miss with every shot.

You can do exactly the same thing with a double-action revolver, or with a little more work, a lever-action rifle or a pump shotgun.  And with pretty much the same results (or lack thereof).  Military snipers know it isn't the hundred shots you miss your enemy with that matter.  It's the one carefully aimed shot that hits.  The sniper's motto is "One shot, one kill."

There are shooters who can fire a repeater — be it lever-action, pump-action, bolt-action, revolver or semi-auto — just about as fast as the action will cycle, and actually hit their targets with every shot.  Every one of these shooters rates the term "expert".  See the example of Jerry Miculek, above.

Now, it is true that the various types of semi-auto action lend themselves particularly readily to detachable box magazines that hold as many as thirty rounds.  But a British Lee-Enfield bolt-action rifle designed in the early 1900s, for just one example, also has a detachable box magazine, one that holds ten rounds.  However, British troops carrying the Lee-Enfield were not issued spare magazines unless theirs became damaged, because the rifle was designed to be reloadable from the top, even just to top off a part-empty magazine, either by loading single rounds or by using a sheet-metal "stripper clip".  A stripper clip held five rounds, and the magazine could be reloaded with stripper clips as fast as — and much more cheaply than — by changing the magazine, and without moving the rifle out of firing position.

Which is more "deadly" — an AK copy with a single thirty-round magazine, that's not really accurate beyond about 400 yards; or a hundred-year-old Lee Enfield, considered "effective" to 550 yards and capable of hitting targets out to a thousand yards, with a full magazine and a pocketful of extra stripper clips?

This applies to pistols too.  The M1911 Colt pistol, among the oldest and best semi-automatic pistols, carries a seven-round magazine that can be quickly replaced with a full one when empty ... but a double-action revolver can be reloaded just as quickly using a speedloader or, in some cases, a moon clip.  Modern high-capacity semi-automatic pistols may hold as many as eighteen rounds; a double-action revolver and two speedloaders will give you that same eighteen rounds, and the only case in which the slight extra reloading time will matter is if you're trying to fire it all at once at a single target.

Now, another thing that is seldom mentioned about semi-automatics is a crucial factor related to their design.  Things like the AK — Avtomat Kalashnikova — were originally designed as relatively-close-range combat rifles.  The first ones were German designs, the MP43, MP44, StG44, and StG45.  Their key functional innovation was to combine most of the power and accuracy of a rifle with the full-automatic fire of a submachinegun.  (In fact, they were originally designed to counter the very effective Russian PPSh-41 submachinegun.)  But, there's a key problem with this.  A traditional full-size rifle cartridge such as is used in most hunting rifles — of any action type — is too powerful to use in a full-auto weapon.  The recoil of a full-power round makes it uncontrollable in full-automatic fire.  The US rediscovered this with the 7.62x51mm NATO round of the M14 service rifle in Vietnam, which is a major reason why the M14 was abandoned in favor of the M16 rifle.

So what's to do?  Well, the solution for all of these "assault" rifles (a term coined by the Germans) was to use a smaller, reduced-power cartridge.  In the German case, this was the 7.92x33mm Kurz, the world's first "intermediate" cartridge.  Drastically cutting the power of the cartridge compared to the full-size 7.92x57mm Mauser cut down on the recoil, which made the weapon controllable in full-automatic fire.  A soldier could also carry more of the smaller, lighter cartridges.

That characteristic continues to this day.  Almost without exception, the semi-automatic rifles that you hear called "assault weapons" fire one of two cartridges: the 7.62x39mm M1943 Russian round fired by the Kalashnikov and its predecessor the SKS (Samozaryadniy Karabin sistemi Simonova), or the 5.56x45mm NATO round fired by the M16/AR15 and related weapons.

Among the least powerful of the centerfire rounds used in "traditional" hunting rifles is the .30-30 Winchester.  It's pretty much considered the lower end of cartridges adequate for deer hunting in most states.  But the .30-30 Winchester is about 20% more powerful than the 7.62x39 M1943.

There's another factor involved here.  Part of the reason why the idea of a less powerful rifle cartridge was accepted in the first place was the realization that if you kill an enemy soldier, you reduce his combat strength by one man.  But if you wound that soldier, on average it takes two men to get him to medical care and treat his wound.  So by wounding one man, you reduce your enemy's combat strength by three.

The reduced power of Sturmgewehr ammunition was acceptable because it wasn't designed to kill.  It was designed to wound.  In fact, after thirty years of complaints from troops, the US Army is finally acknowledging that with the 5.56mm round of the M16, it went too far — the ammunition isn't powerful enough, and will not reliably stop an opponent with a single hit.  There's a very good chance the US Army's next rifle will use a more powerful 6.5mm round, and in fact in Iraq, designated marksmen among US troops are being re-equipped with the 7.62mm M14/M21 rifle (pending full introduction of the 7.62mm M110 Semi-Automatic Sniper System), because they need a rifle that is effective beyond 400 meters, and the current M4 carbine isn't.  The 5.56x45mm round is so lacking in power that it is not legal to hunt deer with it in most states, because it is considered inhumane — it won't reliably kill a deer with a single hit.

But wait, there's more!  Yes, still ANOTHER factor to consider.  Repeating rifles are readily available at the drop of a hat in calibers such as .338 Winchester Magnum, .375 Holland & Holland, .378 Weatherby Magnum, .416 Rigby, all the way up to rounds like .460 Weatherby Magnum that can drop a rhino or a Cape buffalo.  Most of the larger calibers are found only in bolt-action or single-shot rifles (including the double rifles we previously briefly mentioned).  These rifles can be compact and relatively light-weight — because they're strong.  Semi-automatic rifles chambered in calibers more powerful than .300 Winchester are rare, because as the cartridge grows more powerful, a semi-automatic action has to rapidly grow larger and heavier to contain the power of the cartridge.  There are very powerful semi-automatic rifles, some of which even fire the massive .50 Browning Machine Gun cartridge, such as the Barrett M82.  But, just like the cartridge, they're huge — the M82 is 57 inches long and weighs 30 pounds unloaded.

For similar reasons, the majority of semi-automatic pistols fire compact cartridges at best no more powerful, and usually much less powerful, than cartridges readily available in revolvers.  .357 Magnum is one of the most widely-used revolver cartridges of modern times; only recently did the .357 SIG come close to matching it in power.  Only 10mm Auto comes close to matching up to the .41 Remington Magnum, and the 10mm has never been a commercial success.  Semi-automatic pistols firing high-powered cartridges have been comparatively rare, have usually been expensive, and have sold poorly, because most shooters have found them difficult to control, and because the sheer bulk of the largest pistol cartridges makes them infeasible to build a semi-automatic pistol around.  You could build a semi-automatic pistol to chamber something like .475 Linebaugh or .480 Ruger, but if it used anything resembling a conventional semi-automatic pistol layout, you wouldn't be able to get your hand around the grip.

(Recently, some semi-automatic "pistols" have come onto the market that fire 5.56x45mm and other small rifle cartridges.  They are typically modified AR15 rifle actions with a short barrel and no stock, with the magazine well in the standard rifle position in front of the trigger guard.  I personally consider them something of an aberration, and am unable to see any point to them other than "Because we can".)

So, we've come up with the following key points about semi-automatic weapons:

• They can cycle faster than the vast majority of shooters can aim anyway ... but so can most other repeating firearms.
• They fire ammunition that is at best no more powerful than other readily available repeating firearms, and in the case of the most highly publicized types, usually considerably less powerful.
• In many cases, their magazine capacity is no higher than repeating firearms designed using other action types.
• They can be reloaded rapidly ... but so can several other types of repeating firearms.
• They don't necessarily look at all like modern military assault rifles.
• Even those that do look like military machine guns differ functionally from them in crucial respects; they will not fire continuously as long as the trigger is held.

So, knowing what we do now about semi-automatic firearms, we can re-examine the original question, "Why does anyone need a semi-automatic firearm?", and we can ask another question in reply:  "What is so special about semi-automatic firearms, that anyone should have to have a special need in order to have a semi-automatic firearm rather than any other kind of repeater?"

And, honestly, the answer to that question is, "Well, nothing, really."

---

By request, the quick identification guide to action types by functional characteristics and legal status:

Single shot:

• Holds one cartridge at a time.  (But see the note above about double rifles etc, which can be functionally considered multiple-barrel single-shot rifles.)
• Must be manually reloaded by the shooter after every shot.
• One pull of the trigger yields one shot.
• Legal for civilians in the US to own.
• Need not be registered.
• Legal for new firearms to be offered for sale to civilians in the US.

Repeater (other than semi-automatic):

(This category includes pump actions, lever actions, revolvers and bolt actions, among others.)

• Holds more than one cartridge at a time (may be as few as two, or as many as twenty for some .22 rimfire pump-action rifles).
• Once loaded, requires a single additional action by the shooter to chamber the next round.
• One pull of the trigger yields one shot.
• Legal for civilians in the US to own.
• Need not be registered.
• Legal for new firearms to be offered for sale to civilians in the US.

Repeater (semi-automatic):

• Holds more than one cartridge at a time (may be as few as five, or in rare cases as many as fifty).
• Once loaded, the act of firing a shot causes the mechanism to automatically advance the next cartridge into firing position without an additional action by the shooter.
• One pull of the trigger yields one shot.
• Legal for civilians in the US to own.
• Need not be registered.
• Legal for new firearms to be offered for sale to civilians in the US.

(Note:  Under this functional definition, a double-action revolver could be considered functionally the same as a semi-automatic.  Unlike a semi-automatic, though, no additional action by the firer is necessary to continue firing in the event of a misfire; the double-action revolver shooter need only pull the trigger again, whereas with a semi-automatic, the shooter must manually cycle the action to clear the misfired round.)

Fully automatic, aka machine gun:

• Holds many cartridges, usually from twenty to several hundred (in the case of belt-fed weapons).
• Firing a shot automatically causes the mechanism to advance the next round into firing position and immediately fire it, unless the trigger is released.
• When the trigger is pulled, fires shots continuously at a high rate until the trigger is released or the ammunition supply runs out.
• NOT LEGAL for civilians in the US to own without specific Federal permits.
• MUST BE REGISTERED.
• New full-automatic firearms not already registered when the registry was closed in 1986 MAY NOT BE SOLD to civilians, and are legal ONLY for military and law enforcement purchase.

Comments

[jhetley.livejournal.com]

Hey, I trained with the standard issue M16-A1. You want "pie plates", you'd better be under a hundred meters . . .

[cipherpunk.livejournal.com]

An accurized M16A1 can be expected to do 1MOA groupings. An accurized Mini-14 can do 2MOA.

[jhetley.livejournal.com]

I've never met accurized versions of either. I know that with issue M16A1 weapons and issue ammo on the range, prone position, 300 meter hits were rare enough to be noteworthy. With the M14, issue weapon and ammo, 300 meter _misses_ were noteworthy.

I qualified "Expert" with both.

[cipherpunk.livejournal.com]

I can't say about today -- my information is old -- but I know for an absolute and concrete fact that the USMC required their troops to be able to engage targets at 500m with the M16A1. If you couldn't make those shots, you weren't worthy of the title "Marine."

Now that the M4 has become so common, I imagine the range distances have become shorter.

[gdmusumeci.livejournal.com]

I can hold 1-1.5 MOA with a civilian M4gery to about 400 yards... I give out before the rifle does (as can be expected from someone who only goes to a rifle range once or twice a quarter, I fear).

[cipherpunk.livejournal.com]

Currently, as per MCO 3574.2K, 500m marksmanship with the M16 is still part of the Marine Corps rifle curricula. However, it seems (emphasis on that; I'm just skimming it) that it is possible to qualify as a Marine even if you miss the 500m targets. They're required in order to get the highest range scores and bragging rights over your fellow jarheads, though.

[cipherpunk.livejournal.com]

Gah. I should have said the USMC required 500 yard accuracy.

Damn us and our bizarre non-metric distance measurements.

[jhetley.livejournal.com]

My experience was late-Vietnam era, 1971+/-. US Army, we didn't even _have_ a 500 meter target on the range.

I don't know at what point the M16A2 became common, after I served my time, but that was alleged to be much more accurate. I believe the Marine brass were pushing that change.

[unixronin.livejournal.com]

Good on you. :)

[jhetley.livejournal.com]

Well, since I was Signal Corps, it was pretty much wasted ammo . . .