Del-ton/Bushmaster M16A4 Clone
Today, we will be taking a look at my Del-ton/Bushmaster M16A4 clone. With the recent news that the Marines plan to move away from the M16, this feature is especially appropriate, but I think it will also help to show just how timeless the classic full-sized AR rifle is. Initially fielded in 1962, the M16 has lived a long life and undergone a considerable transformation since its inception.  As an M16A4 clone, we can now say that this featured rifle closely approximates the final official version of the legendary firearm.
Parts Used
Upper:
- Bushmaster complete upper receiver assembly
- Semi-automatic bolt carrier group with standard charging handle
- Chrome lined, A2 profile, MP-tested barrel with 1:7” rifling twist rate
- A2 flash hider
- Trijicon ACOG TA11J
- Trijicon Killflash
- TA51 mount
- Knight’s Armament M5 RAS
- Knight’s Armament forward grip
- Knight’s Armament rail panels
Lower:
- Del-ton lower receiver
- Del-ton standard single-stage trigger group
- Del-ton A2 fixed stock
- Del-ton A2 pistol grip
As you can see, this rifle is about as close to a military M16A4 as most of us are going to get. Yes, Colt and FN both offer similar versions that are technically closer (both companies make the real rifles), but this example is close in most of the places that matter. The Bushmaster upper receiver assembly is possibly the most interesting part of the clone as many believe these uppers have US Government pedigree. As some readers are bound to realize, Bushmaster does not typically produce barrels with 1:7” twist rates; most current offerings are 1:9”. Furthermore, I cannot recall a time when Bushmaster commercially offered this particular barrel and flat-topped upper receiver as a combination, except for large custom orders. According to some in the community, these upper halves were overruns from a sizeable contract with a US Government agency several years ago, possibly even as part of the Army’s failed M16A3 purchase back in 2008. Unfortunately, since the general rule is to buy the rifle, not the story, none of this speculation amounts to anything meaningful.
The KAC M5 RAS is an excellent, solid rail that is a great option for those on a budget. While they are a good bit heavier than the standard handguards, the difference is not overwhelming. More expensive rail systems tend to be lighter and slimmer than the M5, but considering that blemished examples are sometimes available directly from KAC for as little as $150, the RAS should suit budget-conscious shooters very well. As a side note, the M5 attaches in a similar manner to the standard polymer forearms and is not free-floated, so users looking for precision will need to be cognizant of the amount of pressure or tension applied to the rail while shooting. I’ve covered the KAC rail panels before, but they do an excellent job of keeping my hands cool, and the KAC vertical grip works as a serviceable handstop that fits the clone look.
The Del-ton parts are leftovers from my original M16A2 clone. When I grew tired of the M16A2 iron sights, I sold the Del-ton upper half but kept this complete lower. The trigger breaks at around 6.25 pounds and has zero take-up. Though I am not a fan of Del-ton upper assemblies (for a lack of configuration options), their parts are well made and have worked nicely on this rifle for over six years.
One part on the lower half that I have often considered changing is the pistol grip. I typically wear a medium-sized glove, so my hands are by no stretch huge, but the standard AR/M16 pistol grip is very narrow. Comically, each time I’ve committed to replacing it, my desire to have a more accurate clone build has overcome my practical sensibilities.
Sights
The Trijicon TA11J ACOG is simply the best optic I have ever used. One of my complaints about the Primary Arms 4x ACSS scope was that I struggle to focus on targets inside of 50 yards. This simply is not an issue with the TA11J. Moreover, the crosshair reticle offers a level of precision not often found in compact scopes.
I can already hear some readers exclaiming that this scope is not proper for an M16A4 clone, and that is true. My rationale for this departure is that the TA11 series is simply better than the TA31 line. Yes, the TA11 weighs around 4 ounces more than the TA31 (9.9 ounces vs. 14 ounces), but the TA11 offers over 50% longer eye relief. This flexibility is greatly appreciated when using the lengthy A2 fixed stock.
As would be expected, the glass in the TA11J is crystal clear, and the illumination offered by both the fiber optics and tritium works well and is practically bomb-proof. The adjustments on my example are tool-less, and each click constitutes 1/3 MOA of shift. I added the Killflash because some shooters have reported that these help those of us with astigmatism. I have noticed no difference, but the accessory does protect the front lens, and the ACOG is one of the few sights that I can use with little distortion.
My only major complaint about the ACOG is that the TA51 mount is average at best. I have noticed that the screws will sometimes loosen after simply sitting in the safe for 3 or 4 months. Even cheaper mounts from Primary Arms have not done this.
Range Report
If I have an AR-related confession to make, it is that I love the full-sized variants and their 20” barrels. Even the excellent SR-15 cannot match the smooth recoil stroke of a properly-built AR rifle. This A4-gery does not stray from this rule, and the beautiful “sproing” sound associated with the AR-15 recoil spring is pleasingly audible after each shot.
As far as accuracy is concerned, the Bushmaster barrel has always surprised me. At 25 yards, I have shot ragged holes using the rifle and ACOG. At 50 yards, 1-inch groups are absolutely achievable. With decent brass cased ammunition, this M16A4 clone is easily a 2 MOA rifle.
Conclusion
Since completing this build, I have largely moved away from building AR-based clones. Generally speaking, clone builds are more expensive and no more functional than similar alternatives. With these factors in mind, this M16A4 replica is still one of my favorite firearms. As a full-length AR, the rifle is an excellent range rifle that is right at home when fired prone or from a bench. While I do not envy the Marines that have used the A4 to clear buildings in urban environments, I have found that it makes for an excellent, surprisingly well-balanced companion in the woods or on the one-way range.
An information security professional by day and gun blogger by night, Nathan started his firearms journey at 16 years old as a collector of C&R rifles. These days, you’re likely to find him shooting something a bit more modern – and usually equipped with a suppressor – but his passion for firearms with military heritage has never waned. Over the last five years, Nathan has written about a variety of firearms topics, including Second Amendment politics and gun and gear reviews. When he isn’t shooting or writing, Nathan nerds out over computers, 3D printing, and Star Wars.