M16A1 BUILD LOG
tHE sTORY
Ente has always been a firearms enthusiast and interested in history, especially World War I, World War II and The Vietnam War. Ever since he first saw the iconic profile of the M16A1 he wanted one of his own.
Soldier of The 101st Airborne Division with his M16A1
Operation “Cook” September 8th 1967
Quang Ngai Province - Republic of Vietnam
President John F. Kennedy
Inspects an M16 in the Oval Office April 19th 1963
Washington D.C. - United States
Why build one?
Well first of all, cost. An actual M16 can cost a pretty penny. Ente built his for less than $950USD with new & reproduction parts.
(Tools not included in that price.)
Second, Ente has been an Automotive Mechanic, Electronic Service Technician, loves to work with his hands and learn new things.
How did he do it?
After some research it turns out the M16, official military designation: “Rifle, Caliber 5.56 mm, M16” was adapted from the ArmaLite AR-15 that was initially developed in 1956. That bit of information led into a rabbit hole on AR-Pattern rifles and how ArmaLite developed the AR Platform and Colt took over the military contract to produce M16s. ArmaLite sold the AR-15 design and the AR-15 trademark along with the ArmaLite AR-10 to Colt's Manufacturing Company in 1959. Colt started selling the semi-automatic version of the M16 rifle as the Colt AR-15 in 1964 to civillians, since then over 2 Million Colt AR-15s have been sold. After Colt's patents expired in 1977, other manufacturers began to copy the design of the Colt AR-15. The term "AR-15" is a Colt registered trademark which it uses only to refer to its line of semi-automatic rifles. Other manufacturers market generic AR-15s under other designations, but are frequently referred to as AR-15s. It is estimated over 22 million AR-15s have been sold.
Alright brief history lesson over.
So after learning that the M16 is in reality an AR-15 by a different name it was an exciting development for building his own. After some looking around and doing research on the weapons system it turns out that there are a few manufacturers that still make “Retro AR” parts. Most commonly today AR-15s have flat top receivers or M16A4/M4A1 style profiles. The integrated carry handle was replaced with a picatinny rail that allows for optional carry handle or most frequently the use of optics such as EOTech, LPVO, etc.
Ente started to do some research into where to find ‘A1’ style parts, the most important to the “accuracy” of the build was the upper receiver. He wanted an A1 upper receiver without the brass deflector with the ‘tear drop’ forward assist. There are A1 style uppers produced with brass deflectors often referred to as ‘C7’ upper receivers referencing the Canadian military’s adoption of the Colt/Armalite AR-15 platform, called the ‘C7 Rifle’ and features the A1 receiver with brass deflector.
Ente went to Palmetto State Armory and purchased a Harrington & Richardson M16A1 Upper Receiver & Barrel Assembly kit. He also got a PSA Stealth Lower Receiver and Harrington & Richardson M16A1 Lower Parts Kit. He also picked up a Luth-AR Buffer Tube Assembly and Harrington & Richardson M16A1 Stock.
Ente knew the M16A1 came orignally with a 20 round magazine so he went to Duramag and ordered their C Products Defense 20 Round Magazine. Of course he got plenty of standard issue 30 round magazines for range days and training but wanted the original look with the 20 round mag for display purpose.
After it was completed he used headspace gauges to check the chamber clearance to ensure the rifle was safe to operate.
Accessories
After sourcing all the rifle build parts Ente wanted some accesories and after a little searching found a Surplus NOS(New Old Stock) M7 Bayonet to install on the barrel for display purposes. Ente also found a Ontario Knife Company leather scabbard for the bayonet since he likes leather holsters & sheaths over plastic. (He originally sourced an M8A1 Scabbard.) He went to SKDTactical and purchased got a Ferro Concepts Slingster in Vietnam Tiger Stripe to use while carrying the rifle during training drills.
After a few months of research, careful planning, sourcing parts and tools, the build was finished.
Did we mention this is the first rifle Ente’s built?
“Building a gun is a lot easier than building an Engine.”
-Ente, February 18, 2025
A list of parts and tools used can be found below. For those who want to build their own M16A1.
Thank you for reading if you made it this far!
-Ente & Maltz
Founders of Functional Reserve Militia
Built in America by American hands with American Made Parts.
ENTE’S M16A1
Parts:
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Upper Receiver & Barrel Assembly
Harrington & Richardson Retro M16A1 20" AR-15 Upper 5.56 1:7
Harrington & Richardson is an American firearms company founded in 1871, originally as Wesson & Harrington, that manufactures handguns, shotguns, and rifles for over 100 years. Producing Garands considered by collectors to be some of the finest ever made. During the Vietnam War, H&R again answered the call to produce rifles for US forces.Product Made in USA
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Lower Receiver
Palmetto State Armory AR-15 Stealth Lower Receiver Stripped
Since its inception, Palmetto State Armory has focused on providing the best quality AR-15 parts and accessories for the best price possible. Following year after year of exponential growth, Palmetto State Armory’s core principle remains the same, and our commitment to freedom before profit remains unwavering.
Product Made in USA
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A1 Parts Kit
Harrington & Richardson M16A1 Lower Parts Kit
Harrington & Richardson is an American firearms company founded in 1871, originally as Wesson & Harrington, that manufactures handguns, shotguns, and rifles for over 100 years. Producing Garands considered by collectors to be some of the finest ever made. During the Vietnam War, H&R again answered the call to produce rifles for US forces.
Product Made in USA
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Buffer Tube Assembly
Luth-AR Fixed AR-15 Rifle Length Buffer Tube Complete Assembly
SThe Luth name is synonymous with Experience, Expertise, Knowledge, Innovation, and has been a driving force in the firearm industry for close to 40 years. Starting as a machinist 40 years ago Randy Luth founded D.P.M.S. / Panther Arms and grew the company to become one of the leading manufacturers of AR-15 firearms and firearm components in the world.
Product Made in USA
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Stock
Harrington & Richardson M16A1 Stock
Harrington & Richardson is an American firearms company founded in 1871, originally as Wesson & Harrington, that manufactures handguns, shotguns, and rifles for over 100 years. Producing Garands considered by collectors to be some of the finest ever made. During the Vietnam War, H&R again answered the call to produce rifles for US forces.
Product Made in USA
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Magazine
C Products Defense 20 Round Magazine
The DURAMAG® story begins with the creation of C Products Defense, Inc. established in Bradenton, Florida in 2011. The company started with the creation of new magazine designs and fresh production techniques. CPD’s work continued with the purchase of all new equipment, tooling, and molds.
Product Made in USA
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Sling
Ferro Concepts Slingster in Vietnam Tiger Stripe
Our products are tested and re-tested by today’s Law Enforcement and Military elite. We listen to our customers’ feedback like they are at the drawing board with us. Made in the United States, every stitch serves a purpose. The stylish silhouette that comes with our minimalist design is a fortunate by-product. Yes, we’ve come a long way from that single sewing machine in a garage to outfitting our modern heroes.
Product Made in USA
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Bayonet
M7 Bayonet
The M7 bayonet is a bayonet that was used by the U.S. military for the M16 rifle. It can be used as a fighting knife and utility tool. It was introduced in 1964, when the M16 rifle entered service during the Vietnam War.
Ontario Knife Company has produced knives for many decades and all have seen combat with U.S. armed forces. Needless to say, these veteran blades are not in the business of giving quarter.
Product Made in USA
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Bayonet Sheath
Ontario Trench Knife Belt Sheath
Ontario Knife Company has produced knives for many decades and all have seen combat with U.S. armed forces. Needless to say, these veteran blades are not in the business of giving quarter.
Product Made in USA
Recommended Tools:
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Upper Reciever Rod
Midwest Industries Upper Reciever Rod
Midwest Industries was founded in 2003 by two partners in the precision machining industry, united by a lifelong belief in American-made products, American values, and the second amendment. Since the company was founded, their goal has been to provide high-quality parts with innovative features at a price point that is attractive for all levels of income.
Product Made in USA
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Handguard Tool
Midwest Industries Handguard Removal Tool
Midwest Industries was founded in 2003 by two partners in the precision machining industry, united by a lifelong belief in American-made products, American values, and the second amendment. Since the company was founded, their goal has been to provide high-quality parts with innovative features at a price point that is attractive for all levels of income.
Product Made in USA
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Vise Block
Pro Mag Lower Receiver Magazine Well Vise Block
Dedicated to only turning out superior products for dependable performance has held true since their conception. In fact, ProMag is one of the leading manufacturers of handgun magazines in the world.
Product Made in USA
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Armorer's Wrench
Magpul Armorer's Wrench
Our name comes from our original product, the Magpul, which aids in the reloading of mags during combat. Founded by a Marine in 1999.
Product Made in USA
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Pin Punch Set
W Wiregear Pin Punch Set
W Wiregear is a brand that makes tools for installing and adjusting handgun sights. Their products include sight tools and pin punch sets.
Product Made in USA
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Pin Starter Punch Set
Wheeler Engineering Pin Starter Punch Set
For over two decades, Wheeler has consistently provided rugged, high-quality tools and accessories that the pros use, to build and maintain firearms. Each product reflects our history of innovation, ensuring that our tools will last a lifetime. We are known for our unwavering commitment to providing tools that are made to build and built to last.
Product Made in USA
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Center Punch Set
WHLLING Center Punch Set
Established in 2016, WHILLING have done offline business operation for many years, their company is dedicated to hand tools, crafts & equipment.
Product Made in China
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Takedown Pin Install Tool
WHILLING Takedown Pin Install Tool
Established in 2016, WHILLING have done offline business operation for many years, their company is dedicated to hand tools, crafts & equipment.
Product Made in China
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Headspace Gauges
Forster Products 5.56 Headspace Gauges
Forster Products has been making some of the world's most popular precision reloading and gunsmithing tools for over 80 years.
Product Made in USA
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Hex Key
Eklind Tool 3/16" Hex T-Handle Wrench
Founded in 1923, Eklind Tool Company is your complete source for the highest quality, professional grade tools.
Product Made in USA
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Snap Ring Pliers
SK Snap Ring Pliers
An american brand, since 1914. Innovating for American Professionals since day one. High quality precision-crafted tools. We continue or commitment to quality innovation for the world's toughest professionals. Tools that work as hard as you do.
Product Made in USA
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Building/Cleaning Mat
2F22E Building/Cleaning Mat
The pattern on the work cleaning mat is very clear, including complex disassembly steps and details. Experience Ultimate Convenience! This cleaning pad is made from eco-friendly, resilient materials, ensuring a scratch-free, durable surface for safe and effective maintenance.
Product Made in China
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Rifle Builder's Manual
AR-15 Rifle Builder's Manual
Rob spent his professional writing career as the editor of several national automotive, off-road and outdoor magazines (including Mustang Monthly, Mustang Enthusiast, Jp, J Rations and Heartland USA), and as a freelance writer, columnist (Guns & Ammo, Petersen's Hunting and Outdoor Life) and photographer.
Product Made in USA
Extras:
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Pistol Grip Plug
MLLL Pistol Grip Plug
Plug has special cavity for storing CR2023 battery and small Allen wrench. You can also store larger battery for your electronic optics, or any smaller object you will need to have quickly accessible. This plug will also prevent dirt from entering the grip. This plug should fit snugly and fits standard A1 or A2 grip. The plug prevents debris from lodging in the cavity of the grip and functions as a shock absorbing pad to protect the when setting the rifle down on hard surfaces.
Product Made in USA
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Threadlocker
Permatex Orange High Strength Removable Threadlocker
Orange Thread locker can be removed with hand tools and does not require heating to achieve removal
Permatex Orange Thread locker ensures that pieces will not loosen or back out over time. 3X the strength of Blue Thread locker, Ideal for High Vibration Applications. Use for: Automobiles, Motorcycles, Heavy Equipment, Marine and Industrial Applications
Product Made in USA
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Adhesive Ceramic Cement
Rocksett
Popular for muzzle brakes / recoil compensators and suppressors, Keeps assemblies from vibrating loose. Electrical insulation - for both A.C. and D.C. up to 20 Radio MHz. Non-Toxic - odorless - non-flammable - Long Shelf life. Stands with oil, fuels, acids and alkalis. No Mixing or priming required.
Product Made in USA
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Speed Loaders
Military Speed Loader Stripper Clips
Devil Dog Depot provides high-quality Marine Corps products and outstanding service to our brothers and sisters across the nation and around the world. Their Mission is to provide our customers with an excellent selection of USMC products, fast shipping, competitive prices and our signature 5-Star customer service.
Product Made in USA -
Cleaning Kit
Military M16 Butt Stock Cleaning Kit
Devil Dog Depot provides high-quality Marine Corps products and outstanding service to our brothers and sisters across the nation and around the world. Their Mission is to provide our customers with an excellent selection of USMC products, fast shipping, competitive prices and our signature 5-Star customer service.
Product Made in USA -
Gas Tube Cleaners
16″ Gas Tube Cleaners for M16/M4
Devil Dog Depot provides high-quality Marine Corps products and outstanding service to our brothers and sisters across the nation and around the world. Their Mission is to provide our customers with an excellent selection of USMC products, fast shipping, competitive prices and our signature 5-Star customer service.
Product Made in USA
Disclaimer: FRM may receive a commission from some of the above links. Any commission made from these referrals are intended to support our production costs and we only refer trusted and personally tested items.We are not professional gunsmiths. We do not provide information that is intentionally incorrect however, mistakes can be made. Our content is made to be historical, educational and entertaining. We are not responsible for any property damage, injury or loss of life if any of the information provided is misused or any activities shown are replicated. Stay safe and exercise caution when handling firearms & tools.