There seems to be a lot of confusion among shooters when it comes to the civilian AR-15 platform and its military counterpart, the M4 and M16.
So, how are they related? And what’s the difference between the two? Let’s take a closer look at these rifles and clear up some of the confusion.
Civilian vs. Military
The AR-15 platform is a civilian version of the M4 and M16 rifles. These rifles are based on the same design, but there are some key differences between them.
The Safety Selector Switch
The AR-15 is a semi-automatic rifle, meaning that it only has the option to fire one round per pull of the trigger.
The M4 and M16 have multiple selector options on the safety selector switch, these options are: safe, Semi-Automatic, this is the same function as the AR Platform, and are either fully automatic rifle or they are three-round-burst depending on the M4/M16 variant.
The fully automatic function on the safety selector switch will allow the rifle to continuously cycle for the duration of time that the trigger is being pulled and will cease fire once the trigger is released or the ammunition is spent.
The three-round burst option has a slightly different function. In this selection on the safety selector switch, once the trigger is pulled, the rifle will cycle three times, firing three rounds in rapid succession.
Chambering Options
The AR-15 is typically chambered in .223 Remington or 5.56 NATO but can come chambered in almost any variety you can think of. The M4/M16 is chambered in only 5.56 NATO. The AR-15 typically has a 16″ barrel but now there is a variety of barrel lengths commercially available. The M4 and M16 on the other hand are issued to the military with either a 14.5″ or 20″ barrel.
Upgradability
The AR-15 can also be fitted with a variety of different stock, grip, and handguard options, with room to upgrade at any point, while the M4 also can come with a collapsible stock and options for upgraded pistol grip, the M16A1 and A2 variants are typically issued with a fixed stock and A2-style handguards. The M16A4 variant will have a quad rail handguard, similar to the M4, as well as a removable carrying handle/sight combo.
These rifles are very similar at their base. However, there is one key difference for those who own civilian AR-15 rifles and those in the military who use the M4/M16 platform. As a civilian you get to pick what accessories you want and can customize your rifle to what you want. While the M4 and M16 respectively have options many civilians do not have access to, when they are issued, they are a “what you see is what you get” item, there is little to no room for upgradability on a personal level.
The AR-15 and M4/M16 platforms are all great. As a civilian, an AR-15 is great. If you want, you can even have an AR-15 built to look like an M4 or an M16, though it may not have the same safety selector switch options.
As a former service member, it is great to be able to customize an AR-15 after being stuck with the same old M4.