How To Build An M14E2 Rifle with Springfield Armory and Sarco

With some spare parts from Springfield Amory, Sarco and Brownells, you can have your own M14A1-style battle rifle with these step-by-step instructions.

January 23, 2023 By Gus Norcross

The story of the M14E2 rifle is simply another chapter in the endless quest to increase the firepower of the infantryman. Single-shot rifles evolved into bolt action repeaters, which were replaced by semi-automatic rifles, and finally select fire weapons. As riflemen, we like to think of combat as a battle between marksmen, but the reality is that firepower rules the day. John C. Garand, the inventor of the M1 rifle, experimented with semi-automatic and automatic rifle designs in the years following World War I, culminating in the adoption of the M1 by the U.S. Army as its standard infantry rifle in 1936. By the end of World War II, interest in select-fire infantry rifles was strong, and prototypes of a rifle like the M1 with a box magazine and full auto capability were under development.

M14E2 Rifle with Springfield Armory and Sarco Parts — (Firearms News photo)

The M1 was a great design and its action served as the starting point for the M14 rifle which replaced the M1 in the late 1950s. The goal of the team that designed the M14 was to develop a rifle with select fire capability that was lighter than the M1 and fed from a 20-round box magazine replacing the eight-round enbloc clips of the Garand. The 7.62x51 (.308 Winchester) cartridge would also replace the .30-06 round which had served since before World War I. The M14 rifle as adopted was basically a product improved M1. It was approximately the same length and weight as the Garand, and it fired a cartridge of similar power and caliber. So, one might ask, where was the improvement over Garand’s masterpiece? The M14 did have full auto capability, but its utility was limited in a rifle weighing less than 10 pounds. In less than a decade, the M14 was replaced by the M16, a truly lightweight automatic rifle chambered in a much smaller caliber, but the M14 soldiered on for decades as a scoped designated marksman rifle in various forms due to its range, reliability and accuracy.

The Pentagon sold the M14 to Congress and the American people as a universal weapon that could replace the M1 Garand, the BAR, the M1 or M2 carbine and the M3 submachinegun. This fantasy was billed as one of the reasons to adopt the new rifle. Certainly, it could replace the Garand. The M1/M2 carbine was designed as a personal defense weapon for someone who really didn’t need a full-sized battle rifle such as an officer or truck driver and, in this role, the M14 would be much larger and heavier. The M3 “grease gun” was issued to tank crews due to its compact size. M14s would not be handier in that role. What about the BAR? It weighed 20 pounds, twice the weight of the M14, and served as the base of fire for the infantry squad.

Historical M14 images — U.S. Army soldier (bottom right) fords a river with his M14A1, sling in carry position. Two U.S. Army sergeants (top right) with M14A1s take a break. ARVN troops (bottom left) with an M14A1 missing its sling and muzzle stabilizer. A soldier from the 25th Infantry Division (top left) cradles his M14A1. (U.S. Army photo, Paul Scarlata Collection.)

Suppression of the enemy with automatic weapons to discourage them from returning fire while the riflemen of an infantry squad maneuvered to a more advantageous position was often the job of the automatic rifleman and his BAR. The BAR was a magnificent weapon known for its reliability and precision, and it saw action from the waning days of WWI to the early days of the Vietnam War. Its weight (and heavy barrel) made it ideal for firing controlled bursts of .30-06 with relative precision. Could the much lighter M14 firing a cartridge of similar power and recoil replace the BAR? Well, maybe, with a few modifications.

Enter the M14E2

The new infantry rifle was originally conceived as two models: the M14 for mostly semi-automatic fire and the M15 with a heavy barrel and bipod for both semi and full-automatic fire. The M15 was declared obsolete before it was produced, and the feeling was that the standard M14 could fill in as an automatic weapon with the addition of a bipod. However, in the words of R. Blake Stevens in his book U.S. Rifle M14, from JOHN GARAND to the M21: “it was still a fundamental of physics that full auto fire from a nine-pound full power shoulder rifle, even with a ventilated handguard and 1¾-pound bipod attached, produced excessive recoil and muzzle climb, and consequently, unacceptable dispersion of shots. In other words, on burst fire, (after the first shot), …the M14 was erratic, impossible-to-control, and hopelessly inaccurate.”

An effort was made to tame the rifle using a special straight line wood stock with an integral pistol grip, M2 bipod, a forward folding pistol grip bolted to the stock and a muzzle compensator. Also developed was a longer version of the standard web sling (64½ inches) with an extra metal clip designed to attach to the folding fore grip when it was deployed. A sling swivel was added to the M2 bipod so that sling tension applied via the forward grip would not stress the wood stook. The new stock sported a rubber pad and hinged butt plate. The M14E2 was officially type classified by the U.S. Army in 1966 as the M14A1, after production of the M14 had ended. In his excellent book on the M14, The Last Steel Warrior, Frank Iannamico states that 8,350 M14 rifles were converted to A1 configuration. Now, let’s look at the parts necessary to build a reasonable facsimile of the M14E2.

Necessary Parts

The M14E2 rifle was built from a full auto government issued M14 infantry rifle. There are some transferable registered full auto M14s in civilian hands, but they are relatively scarce, and I don’t have one so we will use a civilian semi-auto rifle from Springfield Armory, Inc. Springfield Armory has been building high quality replicas of the M14 since the 1970s. I clearly recall sitting in the back row of my history class in high school reading a gun magazine and seeing an ad for the Springfield M1A for the first time. As a collector of military rifles, and an avid student of military history, I vowed to own one someday. It was at least a dozen years before I acquired one and since then I’ve owned a pile of them. I have no complaints. They are accurate and reliable. The rifle used for this article was a base model standard weight M1A (MA9106) graciously supplied by Springfield Armory for our use.

If you possess an original fully outfitted G.I. M14E2 stock you can skip this section, but those stocks are rare and getting rarer. You might be able to buy a nice bare G.I. stock but if you can’t find one, Sarco, Inc. of Easton PA has come to the rescue. They are having replicas of the original M14E2 stock manufactured from a light-colored wood which resembles birch (part number M14364). Most of the original M14E2 stocks were birch. The stock is not supplied with any hardware but a stock ferrule, liner, handguard, repro forward grip assembly and butt pad assembly are available separately from Sarco. A hardware kit to complete the stock with all parts necessary in one package may be available by the time you read this article. The original G.I. issue forward grip and butt pad assemblies are expensive and tough to find. We will use the Sarco repro parts for this build.

Like most commercial stocks, some fitting of the rifle to the stock is necessary. Commercial M14 style receivers from Springfield, Fulton Armory, LRB and numerous others are not exact duplicates of the G.I. original or each other. They’re close, but some adjustment of the stock is usually required for a perfect fit. Before we can test fit the action in the wood the stock ferrule and liner must be installed. The ferrule is simply a stamped sheet metal cap that fits over the wooden lip on the front of the stock. The lip of the front band should bear against it when the rifle is assembled. The ferrule should just press on to the wood but if it can’t be installed without excessive force some wood may be sanded off until it fits. Ferrules on original G.I. stocks were crimped to the wood but they can be epoxied in place if they are loose.

Rifle Prep

I stripped our M1A test rifle so that only the op rod guide remained mounted to the barrel. A stock liner was test fitted to the M1A receiver legs. Ideally, it should fit loose enough that the barreled action can be raised slightly from the muzzle once the liner is installed in the stock. The liner I used for this project fit too tight, so I filed the inside edge of the front vertical liner legs for clearance. The liner is inserted into the mag well of the stock from the bottom with the hooks first and then rotated into position while squeezing the legs together. A special screwdriver bit is required to tighten the two liner screws. I modified a large, flat screwdriver to fit. Badger Ordnance produces a 1/4-inch drive bit for this purpose available from Brownell’s (093-223-040).

With the liner installed, I dropped the M1A into the stock to check for interference. The guiding principle of M14 stock fitting is that no part of the barrel assembly should touch the stock except the lip of the front band where it contacts the stock ferrule. Some problems were immediately apparent. The wood just behind the ferrule was too tight around the gas cylinder and the left sides of the op rod guide and barrel shank were contacting the edge of the stock. I clearanced the area below and around the gas cylinder with a 1/2-inch sanding drum on a Dremel hand grinder. The other two spots only required a few strokes of a coarse file. The Sarco stock is a direct copy of the military original and it fits the M1A receiver pretty well, but it could still benefit from some adjustment. We’re not building a match rifle (which would entail a much more extensive bedding job), we’re just trying to achieve full contact between the receiver and the stock. I traced the outline of the receiver on the wood with a pencil and clamped the stock in my Grizzly mill/drill. Then, I routed the wood on the inside of the pencil lines with a 1/4-inch ball end mill to create grooves for epoxy.

Back at the work bench, I installed my bedding fixture on the barrel. This “fixture” is simply a unitized gas system with the lip of the front band ground off. Next, the barreled receiver is dropped in the stock and the relative positions of the fixture and ferrule are adjusted with a piece of heavy wire (coat hanger) so the bottom edge of the front band is even with or slightly higher than the bottom of the stock ferrule. This slight upward angle of the action will result in some downward pressure on the barrel to dampen barrel harmonics. M1As rarely shoot their best with the barrel free-floated. After test fitting the rifle in the wood and adjusting the piece of wire for the correct angle, we are ready to apply some epoxy bedding compound to the action and the stock.

Brownell’s Acra-Bed

I have built, rebuilt and accurized M1As since the 1980s. For most of my career, I used Bisonite, a steel impregnated brown epoxy which disappeared off the market a decade ago. Since then, I usually bed with Marine-Tex, a hard grey epoxy originally designed for repairing boats. For this project, I chose the Brownell’s Acra-Bed system mainly out of a desire to try something new Epoxies come in two parts, the resin and hardener, and must be mixed in a specific ratio. I use plastic yogurt cups and mix the two parts with a wooden tongue depressor. Then, the epoxy is packed into the stock and applied to the action and the two are assembled and allowed to dry until the epoxy is rubbery, and the excess can be trimmed away. I then let the assembly dry overnight. This whole process can be a bit messy and paper towels should be kept handy. I get epoxy on my hands and sometimes my clothes.

The Acra-Bed system is like using a caulking gun. The epoxy is supplied in tubes and the gun is re-usable. Drop an epoxy cartridge into the gun, install a nozzle and start bedding. The nozzle precisely measures the resin and hardener as it is applied. When you are done, remove the nozzle and throw it away and cap off the epoxy cartridge. My kit did not include release agent for some reason, so I applied a light coat of Brownell’s Acra Release aerosol (081-028-000) to the contact surfaces of the receiver. I use this same product when I’m bedding with Marine-Tex. Paste wax will also act as a release agent. DON’T FORGET RELEASE AGENT!

One last step before we start applying bedding compound to the stock is claying up any voids in the receiver where epoxy could flow and lock the action to the stock. These areas include the horseshoe at the rear of the receiver, the areas just above the rear of the receiver legs and the hole for the connector lock pin at the front bottom of the receiver. It’s a good idea to apply painters’ tape to the stock to catch any overflow of epoxy when the stock and action are squeezed together to minimize clean-up.

With clay and release agent applied to the receiver and tape on the stock I squirted epoxy into the routed areas of the stock and on the contact points of the receiver and set the rifle in the stock with our bedding wire in place on the ferrule. As the rifle and stock are mated some excess epoxy will be squeezed out on to the stock. This is normal. Allow the epoxy to dry for a few hours until it becomes rubbery enough to trim away the excess then set the rifle aside for at least 12 hours before separating the stock and action. Some people bed the top and bottom of the stock at the same time, but I prefer to do it in two separate steps. With the top of the stock completed, the same procedure is applied to the contact points of the trigger assembly. The left and right pads of the trigger housing are traced on the wood, routed and bedded along with the rear area behind the trigger. An important point to remember when bedding the trigger housing is to maintain clearance for trigger movement. A 5/16" groove is milled down the center of the rear bedding pad to keep the trigger from contacting the wood. Failure to do this may result in the rifle doubling. Also, when bedding the trigger housing, don’t fully lock the trigger guard. We want resistance when the trigger guard is locked to keep the rifle tight in the stock and bedding with it slightly open will pull the rifle into the stock nicely.

Rifle Hardware

Before we finish the stock, the external hardware will be fitted. The original buttplate assemblies consisted of a hard rubber pad protected by a folding steel shoulder rest and a sling swivel which could be rotated to the left, allowing the rifle to be slung flat across a soldier’s back. The original assemblies are rarely encountered today and command a premium price if you can find one. Sarco supplied a new repro butt plate assembly minus some mounting hardware and a correct sling swivel. The kit I received was a prototype and I expect later ones will include all necessary screws and small parts. Some fabrication work was necessary to complete the assembly.

The first piece that is mounted to the stock is an aluminum bracket (BRACKET ASSEMBLY, SHOULDER REST) which is part #11 in the attached exploded diagram. The folding shoulder rest is mounted to this plate. Two wood screws, which resemble slightly smaller versions of an M1 Garand upper butt plate screw, secured the bracket to the wood. I dug around in my “coffee can of miscellaneous screws” and found a couple that worked. The shoulder rest came permanently attached to the plate with a long rivet. Next, the recoil pad is attached over the previously mounted bracket. It is secured with two long screws sporting large, flat, slotted heads. These screws are proprietary, and you will not find a set at your local hardware store or probably anywhere else.

The shafts of these screws are identical to standard M14 rifle screws except for the large heads needed to secure the pad so I simply used two standard M14 screws from my parts bin and put flat washers under the heads. The upper screw is screwed through the pad into the wood. The lower screw is three inches long, threaded 12-28 on the end and is inserted through the pad and a hole in the stock and into the sling swivel and a threaded sling swivel bushing. The sling swivel is proprietary to the M14A1 but can be fabricated from a standard M14 swivel by drilling out the threaded hole to 5/16 of an inch and narrowing the tab to approximately .175 of an inch. The tab can be thinned using a file, a belt sander or in my case a milling machine. I bolted the swivel to a block of scrap steel and thinned the tab until it was the correct thickness. The threaded bushing acts as a nut and is placed into the 5/16 of an inch hole in the swivel to secure the lower butt plate screw allowing the swivel to rotate left in its slot in the stock. I had to fabricate a bushing on the lathe. As an alternative, if you don’t care about the swivel rotating, you could just use a standard swivel and round off the end to fit in the slot.

Once the pad is secured with the two long screws a pair of rubber plugs are pushed into the screw holes to cover the heads and the butt plate assembly is finished. If you don’t feel you need the folding shoulder rest on your E2 stock, you can purchase a hard rubber pad designed for it from TreeLineM14. This pad would be suitable for a DMR built on a M14A1/M14E2 stock where authenticity wasn’t a requirement. Moving to the front of the stock, a backing plate is dropped into the forend with the pointed end forward. Two screws drop through the holes in the plate to secure the handgrip. Note that there are six holes available allowing the handgrip to be positioned to suit the firer. The screws supplied with the Sarco repro handgrip were 10-24 x 3/8-inch flat head machine screws. I felt they did not sufficiently engage the handgrip bracket, so I swapped them for 10-24 x 1/2-inch screws. Also, I drilled out the original screw holes in the wood from 11/64 of an inch to 3/16 of an inch so the screws would slip through them easier.

The Sarco stock is a duplicate of the G.I. part so that means it includes a hole at the right rear for the selector switch to protrude. Obviously, the M1A receiver does not sport a selector switch (although some did before the 1986 machinegun ban). However, the M14A1 was select fire and did have one so I installed a dummy selector assembly from Fulton Armory (Fulton-Armory.com). Some wood was removed to achieve a nice fit.

Put It Together

Once the buttplate, handgrip, and selector assemblies were fitted they were removed so the stock could be finished. I lightly sanded the wood to remove any stains or fingerprints and wiped it down with mineral spirits. Original M14A1 birch stocks were finished with a coat of tung oil, so I used Minwax Tung Oil finish. Although the repro stock appears to be made from beech wood the final appearance is very close to original birch stocks. If a darker finish is desired, it could be stained before application of the tung oil finish. After drying, the stock was re-assembled.

The only modifications to the M1A itself were the replacement of the muzzle device and handguard. M14A1 rifles sported a muzzle stabilizer assembly that was slipped over the original flash suppressor and secured to the bayonet lug with a clamp. Current production M1A flash suppressors do not include a bayonet lug because some state legislatures are stuck in 1994 and believe that the inclusion of a bayonet lug on a semi-auto M1A makes it a dreaded “assault weapon” so Springfield eliminated them from all production years ago rather than produce two different types. Unfortunately, we need the lug to secure the muzzle stabilizer, so I replaced the commercial flash suppressor with an original G.I. part. A repro stabilizer from Fulton Armory was installed and clamped to the bayonet lug. As far as I could tell, the Fulton part was a duplicate of the original and it was not a cheap casting. The nut was tightened with the same combination tool used on the gas cylinder plug. The extra mass of the stabilizer may loosen the flash suppressor during recoil.

The first M14 handguards were walnut. These were replaced with a slotted fiberglass model early in production. The slotted handguards were found to break easily and heat waves from the barrel disrupted the sight picture, so they were replaced with a solid fiberglass handguard. Current commercial rifles like our M1A test rifle are supplied with solid plastic handguards which look like the later fiberglass models but are much tougher. I have seen pictures of M14A1 rifles with both slotted and solid handguards. I decided to use a slotted version on our project rifle. Slotted handguards are available from Sarco.

The Bipod

An important part of the M14A1 package was the M2 bipod. Early bipods were not produced with an attached sling swivel, but the swivel is necessary for attaching the M14A1 sling correctly. The bipod I used is a commercial production model sold by Springfield Armory and they are still available through the Springfield online store as part #MA5015. The bipod clamps to the gas cylinder behind the gas cylinder lock and is tightened with a hex bolt. The legs are adjustable for height, and they fold rearward for storage when the rifle is transported. From an accuracy standpoint, attaching the bipod to the gas cylinder was bad but a wood stock was simply not strong enough to support it so onto the gas cylinder it went.

Standard M14 rifles were issued with the same 46-inch cotton web M1 sling developed for the Garand. The M14A1 required a longer 64.5-inch model with an extra clip which attached to the foregrip. Correct installation of the sling was critical to avoid damaging the stock in full auto fire. The foregrip must be angled slightly forward with the section of sling between it and the bipod tight. Pulling rearward on the grip will force the rifle down solidly grounding the bipod and allowing better control of the weapon. If the sling is improperly adjusted the foregrip may rip out of the wood ruining the stock. Original slings are scarce nowadays but a good friend donated one for this article.

A quick note on M1A/M14 triggers is in order. A typical M14 trigger may have a pull weight of more than 6 pounds. Our M1A test rifle was just a hair over 5 pounds out of the box. This is good. I was also impressed with the evenly cut hammer hooks and the time Springfield took to serial number the trigger housing to the receiver. Now, a lot of readers out there who haven’t spent much time with M1As or M1 Garands are going to say “five pounds? That sucks!” but there aren’t many trigger options available for this platform. It’s a battle rifle designed in the ’50s. A gunsmith trained on M1A and Garand triggers can reduce the pull to about 4.5 pounds which is the minimum safe pull weight. Below that, the rifle will probably start to double. Please do not mess with these triggers. Nothing good will come from it. That being said, I reduced the pull to 4.75 pounds on this one. I consider that weight a reasonable compromise.

M14 Ammunition

The M14 rifle was designed to fire 7.62x51 NATO ammo. It was not designed for some of the high performance .308 Winchester ammo on the market today. Some commercial rounds may exceed 7.62 NATO pressure levels and resulting in excessive bolt velocity and battering of the receiver and op rod. The M14/M1A platform is tough but there is no reason to push it beyond design limits. Powders in the burning range of IMR4064, H4895 and IMR4895 are recommended. Standard ammo for an infantryman in the Vietnam War era was the 7.62 NATO M80 ball cartridge launching a 147-grain FMJ lead core bullet somewhere north of 2,700 fps. I had a small stash of M80 manufactured by the Lake City ammo plant in 1962 which I sacrificed in the name of science. I also tested Black Hills 168 HPBT Match, IMI 168-grain BTHP “Razor Core” and two handloads. After shooting M1As for many years I have concluded that a standard rifle with a standard weight barrel is a 1.5 MOA rifle on average with good ammo. My testing of our M14A1 clone for this article confirmed this belief. M80 ball will not impress anyone from an accuracy standpoint but it wasn’t designed for rifle matches. Against enemy personnel or light vehicles, it got the job done.

Some writers disparage the M14 for not having an adjustable gas system like the FN FAL, but it didn’t need one. Unlike the FAL, which was a product manufactured by FN for worldwide sales and possibly to third world countries where ammo quality might not be up to NATO standards, the M14 was produced by U.S. Government arsenals and contractors solely for the U.S. military for use with U.S. ammunition. Ammunition quality at U.S. government owned plants like Lake City was tightly controlled. There was no need to fit an adjustable gas system to allow the rifle to function with inferior ammo.

One interesting thing I found was the effect of the muzzle stabilizer on accuracy. Attaching it added 1.2 MOA (on average) to groups. Most of the photos I have seen of the M14A1 in Vietnam show the muzzle device removed. Maybe this was why. Apparently, the device has a negative effect on barrel harmonics. I left it off for most of the accuracy testing. The attached accuracy and velocity chart shows Black Hills leading the pack in the accuracy department. No surprise there. They usually do. I have this fantasy that someday my handloads will outshoot their factory ammo in a rifle test. I’m still working on it. Accuracy testing was done at 100 yards firing from a bench with the rifle supported by a Caldwell “The Rock” front rest and a rear bag.

A Leupold 4.5-14x MkIV scope on a Bassett Machine mount was temporarily attached during testing to reduce sighting errors. I fired six five-round groups with each type of ammo, threw out the largest one and averaged the other five. The rifle functioned flawlessly. After accuracy testing was complete, I removed the optic and installed the muzzle stabilizer, bipod, front grip and sling to get a feel for how the M14A1 felt in its intended role. It was extremely controllable in rapid fire and the forward grip was great. The shoulder rest wasn’t absolutely necessary, but it helped. I found the stock geometry to be comfortable.

The M14A1 rifle had a short service life but the stock design lived on. McMillan Stocks produced a copy in fiberglass known as the M2A that became standard issue on USMC M14 DMRs for two decades. The McMillan was heavier than its wood forebear and dispensed with the forward grip. These DMRs were precision rifles and were not intended for full auto. I see no reason why the Sarco version wouldn’t be a great DMR stock with proper fitting. Precision stocks need to be rigid and the forend of the Sarco stock is thicker than a standard G.I. model because it was intended to be a mounting point for the forward grip assembly. Also, the pistol grip is very ergonomic, allowing a straight back trigger pull and the butt pad has more surface area than a standard stock. I think my Sarco stock will find a home on one of my scoped precision rifles very soon.