Take Down: SRM Arms Model 1216 Semiautomatic Shotgun

By Frank Iannamico

SRM Arms of Meridian, Idaho, designed their working prototype shotgun during 2001. The weapon was semiautomatic, fed by a detachable rotary magazine and used a roller-locked delayed blowback mechanism. The original design was refined, improved and perfected until it was offered to the public in 2009. The production semiautomatic shotgun was designated as the SRM 1216.

The second-generation production SRM Arms Inc. Model 1216 (12 gauge and 16-round capacity) is a semiautomatic 12-gauge shotgun. The M1216 has a polymer stock and lower receiver to reduce weight and has a billet steel upper receiver. The in-line buttstock is designed to reduce felt recoil, reinforced with Zytel and features a rubber recoil pad. Its length of pull is 12.25 inches to allow for a tactical vest or body armor to be worn, and its average trigger pull is 6.2 pounds. A quick-change, less than lethal bolt assembly is available. The magazine, which runs parallel to the barrel, consists of four tubes, each with its own spring and follower. Each tube can hold up to four shells for a total of sixteen. It can fire either 2 3/4- or 3-inch 12-gauge shells. The shotgun is reliable with game loads, trap loads, slugs, #00 Buck and specialty rounds. The 1216 Model has a hammer-forged 18.5-inch barrel with a fluted chamber and a 7/8-24 threaded muzzle. The finish is high-temperature black nitrate. The model 1216 has an overall length of 32.5 inches and weighs 7.25 pounds. Its barrel length is 18.5 inches, making it a standard title-one shotgun.

Three MIL-STD-1913 Picatinny rails integral to the handguard allow the shooter a broad range of options for mounting optics, lights and other tactical accessories. Pushpin disassembly and a break-open design also allow for easy field stripping and maintenance.

The firearm may be configured for either left- or right-handed use. The cocking handle, safety lever and bolt stop lever can be moved to either side of the shotgun with the removal of several pins.

The SRM semiautomatic shotguns operate on a roller-delayed blowback principle, similar to that used in HK designs. When the trigger is pulled, the force of the fired shell drives the bolt and carrier rearward. This movement is momentarily delayed by the mechanical arrangement of the bolt until the pressure has dropped to a safe limit. As the bolt travels rearward, the fired shell is extracted, and a new shell is released from the magazine into the carrier for loading. Following recoil, the bolt moves forward and loads the next shell. The shooter presses forward on the magazine index lever and rotates the magazine 90 degrees in either a clockwise or counterclockwise direction. The magazine index lever is then released to lock the magazine in place after rotation. Once the magazine is rotated into the proper alignment, the bolt is automatically released, the next shell is chambered, and the weapon is ready to fire. After the last shot has been fired, the bolt locks in a rearmost position.

The magazine quick release is designed for fast magazine changes. The controls to operate the magazine are attached to a trunnion near the front of the barrel. The ambidextrous paddles used to rotate the magazine can be easily operated with the thumb of the forward hand. The magazine release lever is on the front of the trunnion, below the barrel, and positioned away from the shooter. The index finger of the forward hand can easily reach and actuate the release lever. When released, the front end of the magazine tube will drop away from the gun, and the back end rolls out of a recess located at the face of the receiver. Rotating the magazine to the next loaded tube only takes fractions of a second. With practice, magazine changes can be performed in seconds. Empty or partially loaded magazines can only be topped off when removed from the weapon.

Unloading the magazine is easily accomplished by pressing inward on the upper edge of the shell retainers. Caution: The shells are under spring pressure. If not restrained when released, they will fly out of the magazine.

NFA Models

In addition to the model 1216 shotgun, SRM Arms offers the model 1208, which is classified as an NFA short-barreled shotgun (SBS) and has an overall length of 24.5 inches, including a barrel length of 10 inches. The magazine capacity of the short-barreled model is eight rounds. Its weight is 6.25 pounds.

There is also an NFA Model 1212, which has an overall length of 27.5 inches and a 13-inch barrel. Its weight is 6.75 pounds, and its magazine capacity is 12 rounds.

Firearms that fall under the National Firearms Act (NFA) require Federal Registration and a $200.00 transfer tax. NFA firearms are also subject to local and state laws.

During 2012, a select-fire model of the 1216 was introduced. Designated as the MLE (representing Military and Law Enforcement), it is available to law enforcement, government and military organizations. The MLE shotgun has a full auto cyclic rate of 450 rounds per minute.

SRM Arms provides a lifetime guarantee on all its shotgun models.

To Disassemble the Model 1216 Shotgun


Do not pull the trigger while the firearm is disassembled. If the hammer is in a vertical position, do not attempt to close receiver. Make sure the hammer is in a cocked, lower position before attempting to close the receiver.

The magazine must be removed before opening the receiver. Pull the bolt handle rearward to inspect the chamber to ensure that the weapon is not loaded. Release the handle to allow it to return to the original forward position. Note: Do not pull the trigger, the hammer must remain in a cocked position. Locate the latch pin at the rear of the receiver, push the pin through from the right side to the left side; the pin is captive and will stay in the gun. The stock can now be pivoted down away from the receiver. Grasp the bolt handle and pull the bolt and carrier rearward to remove the assembly from the receiver. No further disassembly of the firearm is necessary or recommended beyond this point for the purposes of regular maintenance.

The 1216 shotgun comes from the factory configured for right-handed shooters. Video instructions for the procedure of converting to left-handed operation can be found on the SRM Arms website: SRMARMS.com. To configure the shotgun for left-handed operation, first ensure that the weapon is unloaded. Use the proper tools to prevent damage to the components. Remove the magazine, push out the rear retaining pin and open the receiver. Slide the bolt assembly out of the upper receiver.

Please see the photo essay on the remaining steps of the breakdown...

This article first appeared in Small Arms Review V22N7 (August 2018)
and was posted online on June 22, 2018


Comments have not been generated for this article.