The Delta 14 M1A Chassis – Mossberg it Up

The M1A aftermarket is a weird place. Not a bad place, just an odd one. One big portion of the aftermarket is dedicated to producing chassis systems that replace the stock. These chassis often enhance the accuracy and ergonomics of the old battle rifle. These chassis systems exist in various forms, but none seems more interesting or affordable as the Delta 14 chassis.

The Delta 14 Chassis is a glass-filled nylon design that the barreled action and trigger group drop into without the need for tools. The Gen 2 model you see here weighs only .75 pounds and provides the user with M-LOK mounting points at the 3, 6, and 9 o’clock positions. It’s a pretty simple, and modern design but the real interesting portion is at the ass end of the chassis. There you find a 5/16×18 fastener that will allow you to mount the Mossberg 500 stock of your choice.

The Possibilities

The Mossberg 500 series of shotguns are extremely common and the aftermarket for them is wide open. This means you have more stock options that you think. The Delta 14 Chassis allows you to Mossberg up your M1A. There are lots of options and this includes the slick and always awesome Magpul SGA stock. Heck, they make top folding and side folding stocks that could create an interesting firearm out of an M1A.

You can also take my route and equip Mossberg 500 Mesa Tactical adapter and open your M1A for both AR pistol grips and stocks. Delta 14 offers lots of options and one such option is the folding stock variant. This option gives you everything you need to create a robust folding stock M1A from proven parts.

This includes a Mesa Tactical adapter, an ACE folding stock, a ACE folding stock adapter, and an ACE receiver block. You also get a UTG rail for the M-LOK slots and Ergo M-LOK adapters to provide a better grip on the empty M-LOK slots. Empty M-LOK is like empty MOLLE, it needs to be filled.

The Chassis Itself

The Delta 14 Chassis is simple, but very well made. It looks and feels like a well-made quality piece of gear. The Chassis is very thin and clings to the action and trigger group of the M1A. This tight fit reduces bulk and makes it a comfortable gun to rest against body-worn gear.

The Delta 14 Chassis is firm and tight. There doesn’t seem to be much noticeable flex in any portion of the stock. Most importantly the rear of the chassis, where the action sits, it’s very rigid and strong. The SOCOM 16 sits nice and tight in the chassis and this will most certainly ensure accuracy stays consistent.

Delta 14 Chassis Installation

Removing the trigger and barreled action from an M1A is quick and simple. I’d never done it before, but it took no time to move both pieces and install them into the Delta 14 Chassis. Attaching the adapters, receiver block, folding mechanism and the stock wasn’t hard, but it is time-consuming. Getting everything aligned just right means taking your time. There are a few little screws to attach, receivers blocks to line up, and folding mechanism to tighten down.

Once attached the ACE folding stock hates to fold. It’s quite tight and requires a firm touch to fold. Unfolding is easy though. Once the kit is installed the Mesa Tactical adapter does seem to prevent removal of the M1A trigger group and barreled action. It pins a corner of the trigger group in and prevent removal.

I call it the Paratrooper

An official M14 carbine or paratrooper model never existed, but if it did this is what I envision. I took a little inspiration for the M1A1 Carbine. The base M1A is the carbineish SOCOM 16 from Springfield Armory. The ACE folding stock is rather well made and extremely strong. Cheek weld isn’t great, but it’s a folding stock so you get what you get.

The Delta 14 Chassis offers plenty of room to mount accessories like lights and lasers. The Chassis is super lightweight and keeps the SOCOM 16 model well balanced and easy to handle. I’m feeling like I need an M60E3 style front grip, but I’ve been having trouble finding one.

The SOCOM 16 isn’t exactly a gun built for National Match, but it’s decently accurate. This model came in the Archangel CQB stock. I will say my groups seemed to have tightened up ever so slightly. I imagine if I went with the Magpul SGA stock I’d see even better accuracy with a better cheek weld and a more supportive stock.

That being said I can’t fold an SGA stock and play some IRL version of Tarkov with my M1A Paratrooper. The Delta 14 chassis is a very innovative design that opens up the world of M1A customization to a degree we haven’t seen before. You can use shotgun stocks, AR stocks, and anything in between. The chassis is well made, lightweight, and isn’t just a gimmick. It’s a legitimate customization option for a legacy rifle system, and it helps bring the gun into 2020.


Travis Pike
Travis Pike is a former Marine Machine gunner who served with 2nd Bn 2nd Marines for 5 years. He deployed in 2009 to Afghanistan and again in 2011 with the 22nd MEU(SOC) during a record setting 11 months at sea. He’s trained with the Romanian Army, the Spanish Marines, the Emirate Marines and the Afghan National Army. He serves as an NRA certified pistol instructor and teaches concealed carry classes.