A recent article I did on throwback trench guns prompted a reader to ask a question about the differences between trench guns and riot guns. As I began to type the answer, I realized I didn’t want to write an article in a comment section, so here we are. Today, we will break down the differences between a trench gun and a riot gun.
Disclaimer, the differences are only slight. Both types of guns are in the genre of combat shotguns. At the end of the day, you could toss a trench gun in a riot and a riot gun in a trench, and you’d probably do okay. There are subtle differences that make one better than the other for their specific roles. They do have a few things in common, and the biggest commonality is caliber. While the 20 gauge isn’t anything to laugh at, riot and trench guns are 12 gauge exclusively.
Another thing they have in common is that both guns are fairly outdated. Modern military forces don’t find themselves fighting in trenches very often. While riots still occur and shotguns still get pulled out for those roles, the 40mm launcher has become the more modern choice for riots. These guns are an interesting part of firearm history and a fascinating part of shotgun lore.
What makes a riot gun?
Riot guns feature short barrels typically falling between 14 to 20 inches, with 18.5 inches being the usual choice. Due to the National Firearms Act, shotguns have to have a barrel length of at least 18 inches. Anything shorter requires a tax stamp.
At the end of that barrel sits a cylinder bore choke. Cylinder bore chokes are important due to the characteristics and munitions that a riot gun fires. Those munitions are commonly less-lethal loads. This includes rubber buckshot, rubber slugs, bean bag slugs, and similar. Constricting chokes often cause issues with these types of munitions.
Modern police departments will often dedicate shotguns to less-lethal munitions and less lethal munitions only. They are often fitted with bright orange furniture to ensure the user knows that only less-lethal loads will be loaded into the riot gun. This was less of a concern in the past, and old school riot guns often employed both standard and less-lethal munitions.
Due to the use of lower powered less-lethal loads, a pump-action is the preferred option for a riot gun. Pump actions work with all manner of shotgun munitions from buckshot to slugs, to less-lethal goodies.
A Little Extra Equipment
Slings are handy pieces of equipment on all types of long guns, and trench guns certainly can benefit from them. However, a riot gun has to have a sling. In a riot situation, weapon retention is absolutely a must, as is the ability to drop the gun and go lethal with a handgun or rifle or go defensive with a shield.
Riot guns have a greater emphasis on proper sights over a bead. Sure, beads work but they aren’t the best option. Riot guns must be aimed carefully in urban environments to take down dangerous people in large crowds. Less lethal munitions also need to be aimed carefully at certain zones of the body to minimize harm. Ghost ring sights and rifle sights are popular choices, and red dots have grown exponentially.
A friend of mine works in corrections, and they have a shotgun squad for prison riots. Due to the gas and munitions used, they have helmets with large visors that make getting a cheek weld on their weapon tough. Their solution has been red dots on AR height risers to make aiming easy.
Another important note is the length of pull. On average, the length of pull on shotguns is too damn long with riot guns. The shorter, the better due to modern police equipment including tactical vests and armor carriers that add inches to the body.
What makes a trench gun?
The trench gun will remain largely obsolete until we return to the earth to fight our wars. They rose to fame in the World Wars, and since then, the design of a trench gun hasn’t really been updated. Like the riot gun, the shorter the barrel, the better. A short barrel is easier to maneuver in the tight fighting quarters of a trench.
20-inch barrels seem to be the most popular choice for trench guns. The Winchester M1897, Model 520-30, Model 12, and Remington 1910-A had 20-inch barrels with five-round magazine tubes. That seems like an odd combination, but it’s necessary to accommodate one of the key features of the trench gun, the bayonet.
Bayonet mounts needed a little extra barrel length for mounting, or they did back in the day. The bayonet was necessary for a trench gun and would likely be handy for a riot gun. In a trench, a shotgun that doubles as a spear can be quite nice. Being able to make the shotgun stabby and shooty is handy for extreme close quarters.
On top of the bayonet, a heat shield is also a nice must-have on a trench gun. In close quarters the trench gun could be turned into an improvised melee weapon. The heat shield can help protect the hands of the user who grabs the barrel when using the gun as a melee weapon.
What about slamfire!
Slamfire is fun but not very useful. Aimed shots are much more beneficial than slamfire. Slamfire is tough to aim, offers you barely any recoil recovery, and is only marginally faster than a standard pump-action with a skilled shooter.
Trench guns are not limited to pump actions either. It could be a semi-auto shotgun. The Browning Auto-5 saw limited use in WW1 and WW2. A semi-auto shotgun would be much handier than a slamfire shotgun if the rate of fire is a concern.
Combat Shotguns
The riot gun and the trench gun are both just examples of combat shotguns. These days, the modern combat shotgun takes features from both the riot gun and the trench gun. Mossberg’s 590A1 still fits a bayonet, and the M1014 would have dominated trench warfare. They can both trace their lineage to the classic trench and riot guns.
If you want a breakdown of other combat shotguns, let us know below. We can dive into the subject and talk about coach guns, breaching guns, and more. Even though shotguns have become more and more niche, they are still fascinating parts of modern small arms.
