Trunk Monkey: Shotgun Edition

By Alton P. Chiu

Having a compact, inexpensive and adaptable long gun in the vehicle to supplement a CCW handgun can be beneficial for fending off predators attacking live stock or fighting in the zombie apocalypse. This article investigates the ubiquitous pump shotguns for such roles.

In the American West, pioneers would carry either a rifle or shotgun in a horse scabbard in addition to a pistol on their persons for hunting or defense. Rural citizens today still have the same requirements although their steeds now feed on petrol instead of fodder.

In the urban setting given the civil unrests in recent memory, citizens may wish to supplement their CCW handguns in the same way that police officers supplement their service handguns with patrol shotguns and carbines. To fill this role, the author set out looking for an inexpensive firearm not only because vehicular theft is an all-too-common occurrence, but because not everyone wishes to spend top dollar on a contingency item. As it had been for centuries, the shotgun fits this requirement well.

The Shotgun

The author was able to acquire a surplus Remington 870 Police Magnum for the modest sum of $250 including shipping and FFL fees.

Many classics such as the Ithaca 37, the Winchester Model 12 and the Mossberg 500 have languished on gun store shelves for reasonable prices.

It is worth mentioning that the Police model of the 870 has some differences from the Express model. The Police model features a longer magazine spring, heavier sear spring and heavier carrier spring. The trigger housing of the Police model is made of metal instead of plastic, and its extractor is machined metal instead of the metal-injection-molding of the Express. In addition, the Police model utilizes a ball detent on the barrel to lock the magazine cap whereas the Express locks against a serrated magazine spring retainer. Lastly, the Police model will accept a magazine extension without modification. The reader should weigh these differences when purchasing an 870.

The hard synthetic stock on the author’s 870 measures about 13.5 inches length of pull (LOP, measured from the recoil pad to the trigger) which fits the 5-feet, 10-inches tall author when using the bladed stance. However, it felt long when using the squared-up stance currently favored in action shooting sports. In addition, the comb was high enough to cause a 70% high pattern.

In order to address the ergonomic shortcomings, as well as to make the firearm more compact, the author investigated four different stocks: Hogue short LOP stock (traditional style), Mesa Tactical Urbino stock (fixed stock with pistol grip), ATI Shotforce stock (top-folding) and Choate Telescoping and Side-Folding stock.

Hogue Overmolded Stock

The Hogue Overmolded stock comes in standard (Item# 08710) or 12-inch length of pull (Item# 08730). The short version is discussed below. The grip area is textured and made of a rubber-like material that promotes comfort and secure purchase. A forend (Item# 08701) with the same material is available as well to replace the standard, hard plastic forend.

The Hogue recoil pad is flexible but not tacky. The pad features slits that close completely around the attachment screw head to keep out lint and debris. To locate the slits, the user should compress the pad lengthwise.

The short LOP stock imparted the strength of a solid stock but kept the form factor compact at a 36-inch overall length for good maneuverability and easy storage. The shorter stock worked well with the squared stance for a small-statured tester where she or he can better reach the forend and cycle the action with authority. However, this tall author found the LOP too short for comfortable use. The shortness also made it difficult to pull the shotgun into the body and led to less effective recoil management. Lastly, the shorter length of pull placed the face closer to the receiver. This placed the eye higher over the barrel and resulted in a higher pattern. The Hogue Overmolded stock is comfortable and worked well for small-statured testers. However, the compactness did not outweigh the comfort of a longer stock for the taller author.

Mesa Tactical Urbino Stock

The Mesa Tactical Urbino stock is slightly longer at 12.5-inch LOP, but the pistol grip being much closer to the receiver made the stock feel longer for the author. The higher amount of drop at comb afforded a good sight picture. A cheek-riser, requiring a rail on the stock, is available to accommodate optics. Note that stocks with rails (e.g., SKU 91550) can be used without the riser, but the stocks without the rails (e.g., SKU 91540) cannot be equipped with the riser.

The pistol grip has a distinctive feel because of the square backstrap and 1.25-inch wide girth. Its design ameliorated felt recoil and reduced fatigue. The design prevented recoil from concentrating into the web and instead spread it over the “meaty” part of the hand between the thumb and index finger. The Santoprene beavertail promoted a high grip for better control as well as softened the recoil. The author found the pad of his finger to naturally rest on the trigger face, facilitating an accurate shot. However, the grip shape slightly complicated the trigger group removal from the receiver. In contrast to a traditional semi-grip, a pistol grip prevents the hand from jarring loose and hitting the trigger guard under heavy recoil.

The Urbino stock is available with a standard recoil pad or a Limbsaver model that admirably tamed recoil. The stock also features a wealth of sling-mount options. The bottom of the stock has a traditional swivel attachment. Halfway between the recoil pad and the grip is an attachment point that allows for a US standard 1¼-inch sling on either side or that can be left off to reduce clutter. The last attachment option is at the front of the stock where the user can either thread a sling through, use an HK-style clasp, or not have a mount at all.

The feature-packed and ergonomic Mesa Tactical Urbino stock has a chief drawback of size. Although the length of pull is relatively short, the increased drop at toe and heel in addition to the pistol grip means the shotgun requires more vertical space. The next two sections investigate folding stocks for that issue.

ATI Shotforce Top-Folding Stock

The ATI Shotforce stock (Part# TFS0600) is similar to the Remington factory steel top-folding stock, but it is made of polymer. To deploy, the user depresses the button on the left side and rotates stock down.

It is locked when the button latches into a cutout. The buttpad is then rotated perpendicular and retained by friction. The buttpad is checkered for grip and does not have any recoil absorption. The slight play when deployed does not impede firearm sighting or function.

The length of pull is slightly longer than the standard field stock and stretches the arm out further because the pistol grip is closer to the receiver than the traditional grip. The author also found it difficult to achieve a proper sight picture due to the thickness of the stock. A higher sight plane is necessary with the stock, but the optics interfere with the folding. The ATI Delux Heatshield with ghost ring sights (Part# SBS4600) provides the proper sight picture without interference. Five additional shells can be secured with the Shotforce Shell Holder (Part# SHO0500).

The ATI stock significantly shrinks the firearm footprint without adding much weight. However, it is not quick to deploy and is perhaps best used where compactness and weight are prized, but accurate shot placement at distance is not an overriding priority.

Choate M4 Telescoping/Side-Folding Stock

The Choate stock features side-folding and telescoping abilities. The bracket is made of steel and is notably heavier. It folds to the right and does not interfere with firearm operation because the slight drop at heel moves the stock out of the shell ejection pattern. To unfold, the hinge is pushed down against spring pressure to unlock the two lugs, and the stock is swung around until it solidly locks open with no play.

The stock has two storage tubes like that found on SOPMOD AR-15 stocks; and while the hard rubber buttpad provides a firm grip on the shoulder, it does not tame the recoil. The pistol grip is made of a hard plastic, checkered for a sure grip, and features a non-removable sling loop at the bottom. In addition, there are other attachment points on the hinge and two more on the stock. The stock features a slight drop at heel but still places the head too high for the bead sight. It reduced the footprint, but the solid construction came at the expense of increased weight.

Shell Holder and Magazine Extension

Use cases for the trunk gun are generally of the “grab-and-go” type where the threat is addressed with the ammunition already on the firearm. There are two easy ways to increase the supply: the shell holder and magazine extension.

The TacStar six-shell, side saddle has an aluminum backing plate that attaches to the receiver via the trigger group pins. If the pump were cycled with the left hand too far rearward, it may painfully contact the backing plate. The holder can carry more shells than a typical two-shot magazine extension; it also offers flexibility by allowing slug changeovers. However, the holder nearly doubles the width, and the extra shells must first be inserted before being used.

A magazine extension typically increases shell capacity by two if flush with an 18-inch barrel. The Choate extension (product# 01-04-02) is made of steel and replaces the original magazine cap. The base clamp is attached near the muzzle, providing a sling attachment and preventing damage in case of impact. The magazine extension provides extra ready-use ammunition at the cost of flexibility, and the extra weight at the muzzle can more easily induce fatigue.

Shooting Impressions

A shotgun is violent on both ends. The user can manage recoil by applying forward pressure on the pump while pulling the stock into the shoulder. Even so, the muzzle rise is more notable than that of a .30-caliber rifle.

The author patterned the improved cylinder barrel with PMC low velocity 1200 fps, nine pellets, 00 buckshot against an 8.5x11-inch sheet of paper that roughly approximated the vital parts of a human torso. At 7 yards, all nine pellets landed within 6 inches. Past that distance, not all pellets landed on paper; the results are summarized below.

Fiocchi 1-ounce, 1150 fps Exacta Aero Slugs were also tested for accuracy. At 50 yards off-hand, the author was able to place five slugs into an 8-inch group.

The 1-ounce Fiocchi slug had notably less recoil than that of the PMC buckshot which weighs about 1.2 ounces. Indeed, the buckshot recoil caused the southpaw author’s trigger finger to slam into the aluminum shell holder backing plate when using a pistol-gripped stock. However, right-handed testers did not report similar problems. This difficulty did not arise with the traditional stock because of the different grip angle.


The pump shotgun makes the inexpensive and effective trunk monkey able to supplement a pistol. Its close-range power is undeniable, and its ability to deliver different payloads gives it versatility for differing situations. However, the typical shotgun has low-shell capacity and is not overly compact.

This article explored some options in making the shotgun more compact and ergonomic. Short length of pull stocks are good at reducing length and maintaining rigidity but being too short can be detrimental to ergonomics. A pistol grip provides more control in both handling and recoil but comes at the cost of a larger vertical footprint. Folding stocks are excellent in promoting compactness, but the loss in rigidity with plastic construction can only be addressed with heavy steel.

The low-ammunition capacity can be addressed by shell holders or magazine extensions. The former add flexibility in carrying different shells ready for a change-over and carries more ammunition, albeit not in the magazine. The latter increase the ready-use capacity but add weight at the muzzle, which can induce fatigue.

However configured, having a shot gun trunk monkey is a cheap and effective insurance against aggressive predators, the next LA riots or the dawn of the dead.

This article first appeared in Small Arms Review V21N3 (April 2017)
and was posted online on February 17, 2017


Comments have not been generated for this article.