person cleaning the interior of an AR-style rifle upper receiver with a brush

AR Maintenance Basics: Keeping Your Rifle Reliable Over Time

Maintenance is not optional on the AR platform. It is part of how the system is designed to function. Carbon fouling, heat, and friction are inherent to the operating cycle, and without routine attention, those factors compound into reliability issues that are entirely preventable. To understand…

ByUpper AuthorityApril 15, 20260Comments

Close-up of an AR-15 bolt carrier group showing the gas key and bolt assembly on a white background

Firearms

Best Budget BCG Options for Reliable AR Builds

Choosing the right bolt carrier group (BCG) is one of the most important decisions in an AR build, especially when working within a budget. While many parts can be simplified or upgraded later, the BCG directly affects how the rifle cycles, feeds, and resets. A…

ByUpper AuthorityApril 15, 20260Comments

Two AR-15 upper receivers shown side by side, PSA on top and BCM on bottom, both with 16-inch barrels and M-LOK handguards

Firearms

PSA vs BCM Comparison: Which AR-15 Brand Fits Your Build

For many buyers, a PSA vs BCM comparison is not really about brand loyalty. It is about deciding how much refinement, quality control, and long-term confidence you actually need in an AR-15 setup. Both companies occupy important places in the market, but they do not…

ByUpper AuthorityApril 15, 20260Comments

Partially assembled AR-15 with upper receiver, lower receiver, bolt carrier group, and magazine on a workbench

Firearms

Budget AR Build Guide: Smart Parts and Cost Breakdown

Building a reliable AR-15 on a budget is not about finding the cheapest parts. It is about understanding where cost matters, where it doesn’t, and how the system works as a whole. A well-planned budget build can perform consistently, remain upgradeable, and avoid the common…

ByUpper AuthorityApril 15, 20260Comments

Complete AR-15 upper receiver assembly with handguard and barrel on a neutral background

Firearms

Best AR Upper Receivers by Use Case

Choosing the best AR upper receiver is not just about picking a brand or price point. It is about understanding how the upper assembly shapes the rifle’s performance, configuration, and intended role. For most buyers, the upper receiver is where the majority of functional decisions…

ByUpper AuthorityApril 14, 20260Comments

Close-up of an AR-15 upper and lower receiver separated at the takedown pins

Firearms

Upper vs Lower Receiver: Key Differences Explained

If you are new to the AR platform, the terms upper receiver and lower receiver can sound more interchangeable than they really are. They connect directly, they are often discussed together, and many buyers first encounter them while comparing complete rifles, stripped parts, or upgrade…

ByUpper AuthorityApril 14, 20260Comments

Firearms

Mil-Spec vs Commercial AR Parts: What Actually Matters

“Mil-spec vs commercial” is one of the most repeated distinctions in the AR platform—and one of the most misunderstood. For many buyers and builders, the assumption is simple: mil-spec is better, commercial is inferior. But that assumption breaks down quickly when you look at how AR…

ByUpper AuthorityApril 1, 20260Comments

Close-up of an AR-15 bolt showing locking lugs and front face against a black background

Firearms

Bolt Carrier Group Parts: Complete Breakdown and Function

The bolt carrier group is the central moving assembly inside the AR platform. It handles locking, firing, extraction, ejection, and chambering. When people ask how the system actually runs, they are usually describing the work performed by this group of components. A broader AR platform…

ByUpper AuthorityMarch 21, 20260Comments

Close-up of an AR-15 bolt carrier group showing the carrier body, gas key, and bolt face against a black background

Firearms

How the Bolt Carrier Group Works: A Clear Breakdown

The bolt carrier group (BCG) is the mechanical core of the AR-15 platform. It controls firing, extraction, chambering, and cycling—essentially determining whether the rifle runs smoothly or fails under pressure. If you’re trying to understand how an AR-15 actually functions, the BCG is where that…

ByUpper AuthorityMarch 21, 20260Comments

Close-up of an AR-15 receiver area showing the upper and lower receiver, trigger, magazine well, and optic mounted on the rail

Firearms

How an AR-15 Works: Complete Cycling Process Explained

An AR-15 works by using gas pressure from a fired cartridge to cycle its internal components, eject the spent casing, and chamber the next round. That mechanical sequence is usually called the firing cycle or cycling process. Understanding it matters because the platform is modular,…

ByUpper AuthorityMarch 21, 20260Comments