Brownells 75th Anniversary - A Shooting Heritage

Backseat Backup

Backseat Backup

A Pair Of Truck Guns For On-The-Move Situations

By Tom Marshall Photos By Tom Marshall and Straight 8

The idea of “trunk guns” or “truck guns,” however you choose to refer to them, has made a swift resurgence over the last several years. For the uninitiated, the concept revolves around keeping a long gun in the back of your vehicle for situations where pistols are inadequate. From that point, the truck gun discussion takes on all the fervor of any good gun debate. We worked with Brownells to build two sample long guns to explore the theory and potential capabilities of the venerable truck gun.

Two Truck Guns
One for a rural environment, the other for the urban jungle.


The idea was to create two separate guns — one for a rural environment, the other for the urban jungle. These guns would be built to do all the things reasonably expected of a gun that lives full time in the back of your vehicle, in their respective environments.

Before we discuss the builds themselves, let’s establish exactly what kind of tasks we think truck guns should be responsible for. In a rural or backcountry environment, truck guns are commonplace. The primer-andrust- pickup truck with a rifle rack is part of pop culture imagery from the Bible Belt to the Bread Basket. While typically associated with the first day of deer season, these guns may be pressed into service under other circumstances, and we wanted our rural build to be just as capable in those less-desirable scenarios.

If you’re a cattle rancher driving the fence line of your property, and you spot a predator sniffing around the herd, a truck gun may save your livestock. Likewise, you may require a long gun to fend off criminal trespassers. The long gun may also be used for hunting or pest control, via the removal of nuisance animals from the property.


Our version of the rural rifle started with a Howa 1500 action in .223 Remington with a 20-inch barrel. In case you’ve never heard of Howa, they’re rifles manufactured in Japan that have been around for some time. Before you mutter something about “that foreign crap,” let it be known that Howa has produced rifle actions for Weatherby - no slouch in the rifle community. The action on our test gun was buttery smooth with very little play in the bolt, even when left fully open. There is a manual safety just behind the bolt handle, and it clicks in and out of place positively. The trigger shoe is wide, ribbed, and curved. It’s a two-stage affair with an airy 1-pound first stage and a 2-pound second stage. The trigger pops like bubble wrap at 3 pounds and a couple ounces.

The Hand Guns
A Howa action and an MDT chassis anchor this build.

The single-stack 10-round magazines feature a front-side release mechanism that we found a little awkward at first, but perfectly usable with a little practice. We dropped the barreled action into an MDT chassis platform. The MDT is a skeletonized, space-age frame that uses standard AR-15 pistol grips and buttstocks. Be warned that the pistol grip interface on this chassis will not accept AR grips that have prominent beavertails on the back side.

We tried several different grips before using the VZ Grips G10 AR grip. This is a straightbacked grip much like the original A2 number, with zero beavertail. It fit like a charm. The buttstock was a Magpul CTR with cheek riser. We topped the whole arrangement with a Vortex 1-6x variable with ballistic matched reticle. While not typical glass for a bolt gun, we thought the 1-6x would balance speed with potential distance requirements. The 6x setting is plenty for layman-sized targets at 200 yards. The whole setup weighed in at 8.5 pounds with a single empty mag inserted.

We shot three different loads through the Howa. First was the Norma TAC 55-grain FMJBT. Then we shot Black Hills 62-grain solid copper TSX. Finally, we ran Federal 77-grain OTM. All three loads are match grade. After our first range trip we attached a Coldwell Bipod. This addition does wonders for when you may not have bean bags or a pack to shoot from. For instance, shooting off the hood of your truck.

Our only gripe was that the barrel seemed to heat up quickly. Within the first two magazines, we were seeing significant heat shimmer in front of the scope. While it’s workable, it’s not ideal and may throw off less-experienced shooters. However, this gun isn’t necessarily intended for prolonged engagements or mag dumps. Overall, it wasn’t a huge problem, but worth mentioning.


Our second build was decidedly urban in flavor. We wanted a gun that would fit under the front seat of your SUV (admit it … it’s a minivan with pretensions), but still provide fire superiority over a handgun. The situations where a civilian would wind up needing a long gun in a city or suburban environment are decidedly limited. There has been a notable uptick in riots and violent protests around the country. Should you find yourself boxed in while getting from A to B, a sudden need to defend yourself against multiple attackers is not unfathomable. Neither is the idea of illegal checkpoints or hasty ambushes, in a more protracted breakdown of civil infrastructure.

The Hand Guns
Parts that went into the AR pistol build.

To offer both convenient size and convincing firepower, we chose to build our “long” gun on an AR pistol platform. We wanted to see if we could build an effective Personal Defense Weapon (PDW) without resorting to NFA tax stamps. Our base pistol was a Stag receiver set with an 8-inch barrel and pistol-length gas system. The barrel was topped with a KX3 muzzle device and capped on the back side with a KAK Shockwave blade stabilizing brace coupled and a Law Tactical side-folding adapter.

The trigger is Trigger Tech’s new frictionless drop-in bang switch. This single-stage trigger snaps like a glass rod at 3.5 pounds with no perceptible pre- or over-travel. Our optic of choice was an EOTech XPS-2 featuring Brownells’ own “Circle T” CQB reticle. This reticle modifies the traditional EOTech 65 MOA ring by replacing the bottom hash mark with a small capital T. If you weren’t aware, EOTech’s reticle is specifically designed for a 50-yard zero. If you zero your holosight at 50 yards, that 6 o’clock hash mark is “Point Of Impact” at 7 yards for CQB scenarios. The modified Brownells reticle makes your CQB aiming point all the more prominent. We had never seen this before, but dig the concept.

When folded, the entire package is about 14 inches with no ATF registration required. Did we mention it’s also chambered in .300 Blackout? Because most in-extremis urban shoots are going to be sub-100 yards (really, they’re going to be sub 50-yards) we thought the .300 offered a bit more oomph to deal with those pesky intermediate barriers. You know, things like vehicle glass and sheet rock, which are plentiful in city slicker-type environments.

A word to the wise for those who run, or might run, a .300 BLK AR. Ammo selection is critical as the gas system in most .300 weapons can run either suppressed or unsuppressed. Most guns cannot do both. If you have an adjustable gas block, the valve or setscrew must be dialed in just so in order for the weapon to cycle. If you change bullet weights, or even ammo brands, that adjustable gas block may need to be re-adjusted. After you choose your duty ammo, make sure you run it for a function check.

The bottom of the Law folding adapter has a QD socket, so adding a single-point sling is definitely doable. It’s also highly advised if using this configuration for urban defense. You don’t want to have to lay your gun on the ground just to open a door, climb a ladder, or treat a casualty. Our test gun didn’t have a sling, but the capability is there if you deem it necessary.

Perhaps our greatest learning point with this build was handguard selection. When we built the gun, we used a Brigand Arms Edge handguard, which is made of meshed strands of carbon fiber. On the plus side, this handguard is super light and doesn’t seem to hold any heat at all. The bad news is that there are zero mounting points for accessories. As configured, we were unable to run a two-point sling, white light, IR laser, or even backup iron sights. All of those are very good things to have on a gun that’s supposed to save your ass in a bind.

We requested a replacement handguard, and received a very nice KeyMod number by Odin Works. Always make sure that when you build a gun, you choose components that will allow the gun to do exactly what you want it to do.

We got little use out of the blade as an arm stabilizer. But it provided an excellent cheekweld and made the .300 Blackout highly shootable. Nobody bruised their cheek or thumped their eye with their face to the brace. At the time, the ATF restriction that you can rest a brace against your cheek but cannot shoulder it like a rifle was still in effect. In late March, the ATF issued a letter clarifying its position, stating that shouldering is, in fact, not a violation of the NFA.

Regardless of whether you live upstate or downtown, having a truck gun is at least worth considering. It could be an incredible force multiplier for everything from pest control to self-defense. The builds featured here are just two possible options. There are literally thousands of components out there to help you build the perfect piece of backseat backup for your needs.