Are Select-Fire Guns Practical for Civilian Self Defense?

General Purpose Machine Guns play a critical role in an infantry squad, but do full-automatic firearms have a practical place in civilian self and home defense?

March 16, 2023 By Will Dabbs, MD

The BATF defines a machine gun as any weapon that fires more than one round with a single manipulation of the trigger. Sir Hiram Stevens Maxim patented the first effective self-loading automatic weapon in 1884. This revolutionary invention, likely more than any other, subsequently transformed the way men institutionally kill each other.

Tactical Philosophy

Full auto guns for home defense — A Vietnam War M37 gun truck outfitted with improvised armor and an M60 machine gun. Modern “Technicals” are similar in concept adding speed and mobility to the gun team.

We’ll start with the belt-fed GPMG (General Purpose Machine Gun). Sustained fire automatic weapons represent the center of gravity for most modern infantry operations. Individual members of the combat team support the coordinated application of machine guns. When skillfully employed and amply supported these weapons maximize the effectiveness of any tactical unit. Being on the receiving end of a properly-stoked, deftly-wielded GPMG will completely remove your enthusiasm for moving or shooting back. Sustained GPMG fire keeps an enemy’s head down so your mates can safely maneuver to eliminate him. That’s the point.

Belt-fed guns are meant to be serviced by a team. The gunner fires the weapon, while the assistant gunner ensures it remains reliably fed and accessorized. Ammo bearers pack the bullets. When properly choreographed, these guns provide essentially uninterrupted fire on a target. In a desperate situation, a small group of survivors, friends who have trained together, or like-minded families become a serious force to be reckoned with when able to shoot, move and communicate while supported by well-exercised machineguns. However, running belt-fed GPMG’s effectively is an art.

Machine Gun Management

The Marines use the acronym PICMDEEP. Whenever possible, GPMG’s should be employed in Pairs. They should also be sited to produce Interlocking fields of fire. Fires should be Coordinated and facilitate Mutual support. This requires reliable battlefield communications. Machine gunners should always strive to fire from Defilade. This means that the guns are deployed from behind cover for maximum survivability. The long thin elliptical pattern of rounds impacting downrange from sustained fire weapons is called the beaten zone. Automatic weapons should engage their targets in Enfilade. This means that the long axis of the beaten zone should correspond with the long axis of the target. Think trench lines.

Gunners should keep Economy in mind to conserve ammunition. Lastly, machine guns are critical battlefield assets and should be deployed with Protection in mind. Heavy automatic weapons invariably draw attention. The very sound can be an effective battlefield tool, but care must be exercised to ensure their survivability. The ideal burst length for a belt-fed machinegun fired off of a bipod or tripod is five to eight rounds. All modern belt-fed MGs are air-cooled and most include a quick-change barrel capability. A trained MG team can keep the weapon in action for extended periods with proper maintenance, ample ammunition, and attention to barrel heat.

Going Mobile

The cavemen we fought for the last two decades in the Middle East made extensive use of civilian pickup trucks adapted to carry machineguns. The general appellation is “Technicals.” These jury-rigged gun trucks are ubiquitous findings in most poorly-funded war zones. A decent 4x4 pickup equipped with a belt-fed machinegun combines firepower with cross-country mobility to produce agile power projection. The same desirable attributes that ground-mounted GPMG’s bring to the fight are even more pronounced from a mobile cross-country platform. When employed aggressively along with reliable communications and in concert with other tactical elements, Technicals are effective combat multipliers on any battlefield bereft of anti-tank weapons.

Modern support weapons consume so much ammunition that vehicular resupply is a necessity, particularly if the tactical situation is fluid. American logisticians optimize resupply packages to support the particular weapons and specific tactical scenario. Air-dropped cubes of ammo are even constructed so that you can tell at a glance what’s inside without having to contort your neck no matter how they land.

Machine Pistols

Fully automatic handguns date back to the First World War. The Mauser Schnellfeuer was the selective-fire version of the WWI-vintage C.96 “Broomhandle” pistol. The 1970s-era HK VP70 is capable of firing 3-round bursts with its shoulder stock attached. The Beretta 93R offered the same function. The most popular machine pistol in common use today is the Glock 18. A full-auto Glock runs at around 1,200 rounds per minute or twenty rounds per second. Even with an extended 33-round magazine you’ll empty your gun in a second and a half.

With proper technique a full-auto Glock is actually more controllable than you might expect. Use a good firm grip and lean heavily into the gun as you fire it. Apply aggressive counter-pressure with the support hand and use your body weight to check the recoil. Be stingy with the trigger and mind your fingers. Such machine pistols are popular with Mexican drug gangs. If your mission is to assassinate some poor slob in a porta-john I can think of no better tool. For most anything else, you’re better off sticking with one shot per trigger pull on your favorite defensive handgun.

Submachine Guns and Assault Rifles

A sound-suppressed 9mm submachine gun (SMG) is likely the best home defense tool ever devised. These weapons offer trivial recoil, maneuver easily in tight spaces, and are easy platforms to learn well. When employed as part of a coordinated team, pistol-caliber SMG’s or selective fire assault rifles are in their element during CQB (Close Quarters Battle) operations.

SMGs were long considered the tools of choice for counter-terrorism applications. Assault rifles are similarly effective but offer longer range. Though a shoulder-fired automatic weapon can indeed be a profligate bullet hose, with appropriate technique it becomes a precision instrument. A single properly-placed round is an effective man-stopper. Several deposited simultaneously in a space the size of a dinner plate are even more so. Like good writing, keep your bursts concise.

Lean into the weapon and let your body weight counteract recoil. Tuck the strong elbow in tight and drive the gun with your weak hand. Your sights will only be useful for the first round, but with practice comes precision. After 100 rounds you’ll be keeping most of your holes on a standard silhouette. After a thousand you can all but write your name with a decent SMG. Muzzle blast with short-barreled assault rifles, particularly when fired indoors, can be seriously disorienting to all involved. Sound suppressors not only reduce noise, but allow a team to communicate more efficiently while reducing stress.

An UZI runs at around 600 rounds per minute, while an MP5 is about 150 to 200 rpm faster. WW2-era Stens, MP40s, and Grease Guns are closer to 500 rpm. Gordon Ingram’s 9mm M10 cycles at 1,200 rpm, while the .380ACP M11 is more like 1,600. Most 5.56mm assault rifles cycle between 600 and 750 rpm. Each gun’s cyclic rate describes a unique personality.

Coordinated CQB with multiple shooters is arguably the most dangerous of all human pursuits. Choreographing actions on the objective in a built-up area requires extensive training, good communication, mutual trust, and unwavering discipline. What the trained survivor group gets for that investment is the best possible chance of victory when life goes truly pear-shaped. Keep in mind that most of these weapons run just fine in semi-auto as well. Just because it has the capability to fire on Full Auto doesn’t mean you have to use it that way.

Practical Details

WW2 American General Omar Bradley opined, “Amateurs talk strategy. Professionals talk logistics.” In addition to artistically employing these devastating tools, you must also keep them supplied. Packing a lot of ammo is invariably heavy.

100-rounds of belted 7.62x51mm ammo tip the scales at about six pounds (WW2 German 10-man squads carried 1,800 rounds for their MG42). Half a dozen loaded 30-round M4 magazines weigh about the same. A nicely accessorized M4 can flirt with ten pounds. Add to that fifteen pounds’ worth of body armor, a Camelbak full of water, and something to protect your cranium and you’re rocking a proper burden. Invest a week navigating a wrecked cityscape thusly encumbered on foot and you’ll come to appreciate why every real soldier’s day begins with physical training. You’ll also begin to understand why Technicals are so effective.

Good technique conserves ammunition. The original M16A2 and M4 carbines both incorporated a 3-round burst limiter. The subsequent M4A1 reverted to the traditional full-auto capability. A trained and disciplined trigger finger can accomplish the same three-round bursts while still retaining the option of more aggressive fire if the circumstances (counter-ambush, breaking contact) dictate.

Contrary to popular belief, machine guns are not illegal in America. Twelve states prohibit or severely limit ownership, but the remaining thirty-eight impose no further restrictions beyond those mandated by the Federal government. It is simply that transferable machineguns are really, really expensive. The 1934 National Firearms Act imposed a $200 transfer tax on the sale of machine guns as well as such stuff as sound suppressors and short-barreled weapons. That would be more than $4,000 in today’s money, and most folks were broke back then. However, over time inflation castrated the transfer tax.

The satirically-labelled 1986 Firearm Owners Protection Act prohibited further manufacture of automatic weapons for sale to civilians. This capped the supply at 182,619 registered transferable machineguns. Market forces have subsequently pushed prices up astronomically. A transferable M16 that cost $600 back in 1987 would run thirty grand today. Certain models (M10/M11s, Sten guns, M2 carbines, Reisings, Maxim Guns) can be had more reasonably. If you have deep pockets, Ruben Mendiola at DealerNFA.com typically has a nice selection.

Ruminations

The recoil impulse from a single 5.56mm round is piddly. Several in rapid succession can become substantial. Mastering the physics takes a little practice. The relative effectiveness of automatic weapons is a function of the mechanical specifics of the gun combined with the skill and discipline of the operator. A well-run pistol-caliber submachine gun is a tactical objet d’art. These weapons are easy to tote and inimitably precise up close. The lack of recoil and modest muzzle signature, particularly with a sound suppressor attached, make them fairly forgiving. For someone first tasting the genre, a 9mm subgun is the ideal training platform.

A selective-fire assault rifle will reliably clear a room and instantly put down a close-range threat while still remaining effective out to several hundred meters. In their modern guise, these guns offer many of the desirable attributes of the SMG along with much better mid to long-range performance. There is a reason that every military in the world issues these particular firearms to their ground troops.

Belt-fed guns will make the Bad Guys become one with the earth long enough for your buddies to close with and eradicate them. Running these guns for maximum efficiency takes teamwork and training. However, when done well coordinated employment of multiple belt-fed GPMGs becomes an all but irresistible force. These same weapons mounted atop a pickup truck are even more versatile.

Beyond proper training and technique, the Achilles heel for most fully automatic weapons is going to be ammunition resupply. Particularly in the case of belt-fed guns, their prodigious appetite for ammunition introduces a critical degree of logistical complexity that must be managed soberly. However, it is the aggressive employment of automatic weapons that most transformed small unit combat between the world wars. Those same transformational lessons shape the tactical landscape today.

About the Author

Will is a mechanical engineer who flew UH1H, OH58A/C, CH47D and AH1S aircraft as an Army Aviator. He is airborne and scuba qualified and summited Mount McKinley, Alaska, six times…at the controls of an Army helicopter. After eight years in the Regular Army, Major Dabbs attended medical school. He works in his urgent care clinic, shares a business building precision rifles and sound suppressors, and has written for the gun press since 1989.

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