For the most part, the design of the AR-15 is made up of several very simple and almost toy-like parts. Built of plastic and aluminum, apart from the barrel, the rifle is ultra-lightweight and can come together from parts found almost anywhere.

I have several of these rifles that were made up from as many as 30 different parts, with none of them being the same brand or manufacturer. You could say that this is a true modular rifle of the first degree.

Currently, even here in the far western town of Rapid City in South Dakota, we have an indoor gun-range that offers shooters the ability to build an AR-15 onsite from a parts locker in the store/range setting. Walk up, decide what you want, and with the help of a competent gunsmith, you can build the rifle in an hour or less.

The primary parts associated with the basic field-stripped AR-15 begin with the upper, or the barrel and receiver bolt assembly. The second major part is the complete lower receiver section that also houses the butt-stock and pistol-grip. With only two very easily removed primary pins, these two parts are assembled in seconds, with some very limited practice.

The forward hinge pin on the receiver acts like a hinge. The upper section ties into the lower section of the receiver and, with the pin installed, allows the upper to rotate forward in order to allow the bolt assembly to be installed or removed for cleaning. Assembly is secondary, but it is ultra-important when installed in the rifle correctly.

When addressing the second pin, which is located at the rear of the receiver’s lower section, as the upper is pivoted back and down into the lower, it aligns with the holes at the receiver rear, and that second pin is then installed.

At this point, the weapon is now assembled.

It is not a stretch at all when considering the AR-15 as the most flexible weapon in the world. Buttstocks, muzzle-breaks, front-hand guard designs, triggers, and grips to name a very few, make up a small part of the hundreds of custom and generic parts that can be tacked onto the AR-15.

It makes no difference if you are shooting the larger AR-10 in a 300 Win Mag or the standard platform in the .223 Rem (5.56NATO). The assembly process is exactly the same every time.

The AR-15 as a design retains many different and varied dimensions to the basic rifle, Barrel extensions as in suppressors can be installed with the aid of a simple wrench and the addition of a special muzzle adaptor that allows the thread patterns on the suppressors to be attached to the primary barrel. When the AR-15 is “chopped” as in a very short entry weapon all that needs to be addressed is the fact that the barrel is long enough so as to accommodate the required gas block on the weapon. No gas block and you have a single shot at best.

When building the AR-15 from scratch, stay way for aluminum gas block housings. These metal fittings will expand or shrink in cold weather and cause the weapon to fail when using the available spent gasses in the barrel during firing. In most cases, I have found that when taking the weapon down for service cleaning I leave the block section of the barrel/muzzle alone. Using a good deep crud cleaner and carbon remover during a heavy bore soaking process seems to keep that area of the weapon in good working order.

With the gas block working the only other area of direct concern is the bolt assembly as it pairs to the receiver and barrel lockup itself. Here the takedown is field dirt simple, and with the weapon open ( rear pin removed ) hinge the upper unit out of the lower section of the receiver, and by pulling straight back on the operating handle ( rear of the bolt assembly ) remove the handle and slide the bolt free of the receiver itself. Lubrication here and cleaning are essential, but it was found that in combat conditions even pure water would get the rifle up and running if in a tight spot.  As to exactly where that water came from is a subject best left for another day.

A final area of direct concern is the recoil compression piston that is installed directly behind the receiver in the buttstock itself. If the do-it-yourself gunsmith besides to play in this area of the Ar-15 and makes use of an aftermarket recoil suppression devise (part ) when the wrong part is installed and not set up for the rifle being modified the end result is a rifle that will not function.

When in the field or after a day out in nasty conditions the AR-15 with its two-pin design is among the easiest rifles to maintain that has ever been built as an autoloading rifle. In most cases, it takes massive amounts of time to strip many other rifle designs in an autoloader, but here it is that simple two-piece system with very few parts that require removal. 

Long Range school using Smith & Wesson AR designed rifles. The AR is a simple rifle to modify for special needs. In this case .308 Winchester for 1000 yard work.

Author Loyal Brezny, shooting long-range school at 7000 feet with Smith & Wesson AR-10 .308 Win.

All elements are doable with the AR Pattern rifle. Keep it clean and it will meet your needs.

Author Loyal Brezny, shooting a Federal Cartridge event in South Dakota. Note the suppressed muzzle on this Savage modified AR-15.

Suppressed long-range AR in field operations when testing new Federal Cartridge ammunition. They are dependable, accurate, and come with just a few primary parts.