A pistol-caliber carbine (PCC) built on the AR-15 platform chambered for 9x19mm Parabellum cartridges often utilizes a magazine adapter to facilitate the use of readily available and often less expensive handgun magazines. These adapters allow the AR-15 to accept magazines designed for popular handguns like the Glock, providing a cost-effective and practical solution for training, competition, or recreational shooting.
The adaptation of the AR-15 platform to accept common handgun magazines offers several advantages. It allows shooters to consolidate ammunition types, simplifying logistics and potentially reducing costs. The widespread availability and typically lower price point of 9mm handgun ammunition, compared to rifle cartridges, also contribute to the appeal of these conversions. Historically, adapting existing platforms to new calibers has been a recurring theme in firearms development, driven by factors such as cost, availability, and logistical efficiency.