M16A1 BUILD LOG
How & Why
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.
Why build one?
Well first of all, cost. An actual M16 can cost beacoup bucks, thousands of dollars for those unfamilar with the phrase. He built his for less than $900 USD with new & reproduction parts.(Tools not included in that price.)
Second Ente has been an Automotive Mechanic, Electronic Service Technician and loves to work with his hands.
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 marketed generic AR-15s under other designations, frequently referred to as AR-15s.
Alright brief history lesson over.
So after learning that the AR-15 is in reality an M16 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 a ‘slick side’ upper receiver without the brass deflector and with the ‘tear drop’ forward assist.
After Maltz sent him a video of someone “Melting an M16 barrel after over 1,000 continuous rounds being fired” RangeTool commented on the video posted on how it was a reproduction build, Thank goodness.
From that video Ente was referred to RangeTool who has been amazing to work with, RangeTool was founded in 2010 and is based out of Northern Minnesota and source all their materials locally in the USA. There was an issue with Ente’s order of the M16A1 upper receiver and they were prompt to respond and ship a replacement and paid for return shipping. Their customer service is impeccable.
After ordering the receiver he still needed the rest of the rifle, after some more searching around he found Linemount, a USA based company who offers retro firearm parts including M16. He sourced the handguard and pistol grip from them and their prices are modest and quality is top notch.
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 and 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.
For the rest of the build he decided to go to Palmetto State Armory for the Lower receiver and parts kit. He chose a PSA Stealth lower, and Freedom Rifle 20” Barrel parts kit. The freedom parts kit came with a flat top upper receiver and A2 handguards that were removed and he installed the barrel onto the A1 receiver. From there it was time for assembly of the lower, installing the gas tube and bolt carrier group and final assembly with furniture then the M16A1 reproduction was complete.
After it was completed we 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 also went to Magpul and purchased a Ranger green MS1 sling for 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.
Note: The A2 freedom kit used is not a pencil barrel profile and it has an A2 Birdcage muzzle device, it is not 100% era correct for an M16A1. (The A1 has a lightweight barrel with a 1:12 inch twist, the A2 has a barrel that is heavy contour in front of handguards and is 1:7 inch twist.) With that in mind Ente was alright with these concessions he made as the barrel is a bit stronger and the A2 birdcage is a compensator by technicality (but is classified as a flash hider) so it will reduce muzzle rise. The A2 buttstock is 5/8 inch longer than the A1 buttstock and the one used is a ‘Type E’ (Type E stock is essentially the same as the Type D except the butt-pad was made from a hard plastic, is affixed with two screws, and incorporates a butt-trap door for housing a cleaning kit)
At the end of the day it looks very close to period correct and the majority of people would not notice or care.
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
A1 Upper Receiver with Rear Sights, Forward Assist and Dust Cover
Founded in 2010 residing in Northern Minnesota, Range Tool Company has been supplying OEMs and Brands across the country in the firearm industry.
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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Handguard
M16A1 Retro Triangular Handguard Set
Linemount is dedicated to providing hard-to-find, high-quality firearm parts and accessories for responsible shooters and enthusiasts.
United States based company.
Product Made in Taiwain.
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Pistol Grip
M16A1-Style Pistol Grip
Linemount is dedicated to providing hard-to-find, high-quality firearm parts and accessories for responsible shooters and enthusiasts.
United States based company.
Product Made in Taiwain.
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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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Parts Kit
PSA 20" Rifle Length 5.56 NATO 1/7 Nitride A2 Freedom Rifle Kit
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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Sling
Magpul MS1 Sling in Ranger Green
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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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.
frm is PROUD TO SUPPORT AMERICAN BUSINESSES
Tools:
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Barrel Extension Vice Block
Magpul BEV Block
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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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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Takedown Pin Install Tool
BESTNULE Takedown Pin Install Tool
Established in 2016, BESTNULE have done offline business operation for many years, our company is dedicated to arts, crafts & sewing equipments.
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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Long Arm Hex Keys
AmazonBasic Long Arm Hex Keys
AmazonBasics is a private label brand of Amazon that sells everyday consumer goods at lower prices. The brand includes products for the home, office, electronics, and more.
United States based company.
Product made in China.
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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 any 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 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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