How To Clean Your AR-15

Range issues and why the Mark 18 needs cleaning

At the range, the Mark 18 starts to hesitate when chambering the first round from a fully loaded magazine. The rifle has roughly 2,000 rounds on it since the last cleaning, and the sticky feeding makes it clear that maintenance is overdue. The discussion turns into a walkthrough on how to clean an AR-15, using this heavily used Mark 18 as the example. The goal is to show a basic, repeatable process for owners who may be new to the platform or who tend to delay cleaning until reliability issues appear.

Safety checks, magazines, and sling setup

Before any disassembly, the hosts emphasize confirming the rifle is clear and safe. The magazine is removed and the chamber is checked. A SCAR-pattern magazine from an FN SCAR 16 is shown in the gun, mainly because it matches the rifle aesthetically. A Ranger Band on the stock is explained as simple sling stowage, keeping the sling secured and out of the way while still allowing manipulation of the controls and normal shooting. With the rifle confirmed empty, they move on to basic AR-15 takedown steps.

Separating upper and lower and removing the suppressor

The upper and lower receivers are separated by pushing out the two self-retained takedown pins. This basic step is highlighted for new AR-15 owners who may not have field stripped a rifle before. The host notes that for a true deep clean, accessories would normally be removed, but in practice that only happens when parts like the trigger are being replaced. A suppressor is threaded on the Mark 18, and it is removed to make cleaning the bore and upper easier. When asked about cleaning a silencer, the host explains that this particular one is not routinely cleaned; carbon buildup is not considered harmful and may slightly affect sound. If desired, a suppressor can be soaked in a bucket with WD-40, Ballistol, or a similar solution, then rinsed and dried.

Disassembling the bolt carrier group

With the upper separated, the charging handle is pulled to the rear and the bolt carrier group is removed. The carrier, once bronze-colored, is now heavily fouled, illustrating how dirty a direct-impingement AR-15 can become. The bolt carrier group is broken down into components: the firing pin retaining pin (cotter pin), the firing pin, the cam pin, and the bolt itself. The firing pin is removed first so the bolt can be pushed rearward, allowing the cam pin to rotate and be taken out. The bolt is then pulled free from the carrier. The amount of carbon on these parts shows how the AR-15 “craps where it eats,” concentrating fouling in the bolt and carrier area.

Soaking parts and carbon removal tools

Small parts from the bolt carrier group are placed in a Tupperware-style container filled with cleaning solution or CLP, with Ballistol mentioned as a preferred option. Adequate ventilation is recommended when using strong solvents. The charging handle can also be soaked without harming it. A dental-style pick or scraper is used to remove carbon from the bolt, especially the rear section where fouling accumulates. The host notes that many shooters obsess over cleaning every trace of carbon from this area, but the rifle will generally run even when it is heavily coated. For those who want it spotless, soaking followed by careful use of a copper brush and scraper is suggested, while avoiding damage to seals and critical surfaces.

Using the Gunmaster .223/5.56 cleaning kit

A compact Gunmaster .223/5.56 cleaning kit from the Classic Firearms website is opened and used as the primary tool set. The kit includes brass rods, a chamber brush, and a dental-style tool that would have made removing the firing pin retaining pin easier. The scraper is recommended for breaking up stubborn carbon on the bolt and other small parts. The host points out that the kit is designed more for chamber and basic bore work than for running the full length of the barrel. The components thread together to form a short rod that can accept the chamber brush, making it suitable for focused cleaning around the locking lugs and throat area of the AR-15.

Cleaning the chamber with a dedicated brush

Attention shifts to the chamber, which is described as heavily fouled after extensive firing. Instead of using a finger to feel the buildup, the dedicated chamber brush from the kit is attached to the assembled brass rod. The brush has copper bristles that extend into the bore and stiffer steel bristles that scrub the chamber itself. The rod is inserted into the upper receiver so the brush seats in the chamber and the first part of the barrel. A T-handle piece is added to the rod to provide leverage, allowing the user to twist and work the brush thoroughly. This action breaks up carbon, brass, and copper residue that accumulates around the chamber and locking lugs, preparing the rifle for further bore cleaning and reassembly.