With accessorized commercial AR-pattern carbine, all of the add-ons and accessories in the world cannot make up for a core carbine that is not up to snuff.
Despite what you may think, your AR15 is not truly Mil-Spec. Mil-Spec is short for Military Specification. While the term military should be self-explanatory to anyone reading this publication, the dictionary defines “specification” as (among other things) a detailed description or assessment of requirements, dimensions, materials, etc. Virtually every product you own or use on a daily basis has a manufacturing specification dictated by the buyer, manufacturer, or some other entity. With the military being both the purchaser and end-user, Mil-Spec is the set of specifications they use in their procurement process to ensure that the products they are purchasing meet their criteria for their needs. Everything in the military has a specification it must meet in order to be purchased.
Bolt carrier on the right meets the specification, bolt carrier on the left does not.
The US Army Specification for the M4 carbine and M4A1 carbine are MIL-C-70599A and MIL-C71186 respectively, with the primary difference between the two being that the former is capable of three-round-burst fire and the latter is fully automatic. This brings us to our very first point of contention and the reason that the carbine sitting in your safe and why all of the carbines currently sitting in the rack at your favorite dealer do not meet the military specification. The Hughes Amendment to the Firearm Owner’s Protection Act of 1986 barred from future manufacture any select-fire or fully-automatic firearms for the commercial (meaning non-government) market. Any firearms that fell into this category were already required to be registered due to the National Firearms Act of 1934, and the FOPA of ‘86 now meant that only those already registered could be subsequently legally transferred from one owner to the other and then only under the existing provisions of the NFA of ‘34. Confused? Thank a Congressman. The short version is that unless you have a full-auto or burst firing AR-pattern or M16 carbine and it has subsequently been converted to meet all of the other specifications of the current military M4 and M4A1 carbines, the rifle in your safe does not meet the military specification.
With accessorized commercial AR-pattern carbine, all of the add-ons and accessories in the world cannot make…
by Kevin Davis / Sep 1, 2010