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AR Parts, Parts for Glock^® & SIG Sauer P365, and Reloading Components

Welcome to Arm or Ally, a trusted destination for serious builders and shooters looking for AR platform components, aftermarket parts for Glock^® pistols, aftermarket slides and barrels for SIG Sauer P365 pistols, and high-quality reloading supplies. Our catalog focuses on carefully selected components for builders who value reliability, compatibility, accuracy, and consistent performance.

Whether you’re refining an AR-15 rifle with precision AR-15 parts, building a long-range AR-10, configuring a compact AR-9, upgrading a Glock^® pistol, working with the SIG Sauer P365 platform, or loading precision ammunition with our reloading components, Arm or Ally provides a focused selection of components for a wide range of builds and shooting disciplines.

Our mission is simple: provide dependable components, useful technical information, and a well-organized selection that helps builders identify the right parts for their rifle, pistol, or reloading setup.

AR-15 Parts and Components for Precision Builds

The AR-15 platform remains one of the most versatile rifle systems available, with a modular design that allows builders to configure nearly every major component around the intended application. Arm or Ally carries a broad selection of AR parts and accessories covering complete builds, upgrades, replacement components, and specialized configurations.

Builders can configure their rifles with AR-15 upper receivers, free-float handguards, bolt carrier groups, and precision AR barrels. Additional components such as AR-15 triggers and AR gas systems allow builders to further configure the operating characteristics of the rifle.

From lightweight configurations and general-purpose rifles to competition and precision-oriented builds, the AR-15 platform provides substantial flexibility in component selection.

AR-10 Parts for Large-Frame Rifle Builds

The AR-10 platform extends the modular AR design to larger cartridges commonly used for long-range shooting, hunting, and precision rifle applications. Arm or Ally carries components for large-frame builds requiring appropriately matched receivers, barrels, operating components, handguards, gas systems, and recoil systems.

Because AR-10 and other large-frame AR specifications are less standardized than the AR-15 platform, component compatibility is especially important when selecting parts for a new build or modifying an existing rifle.

AR-9 Parts for Pistol Caliber Carbines

Pistol caliber carbines combine familiar AR-style controls with cartridges commonly associated with handguns. Our AR-9 parts category covers components intended specifically for 9mm and other pistol-caliber AR configurations.

Purpose-built receivers, barrels, bolt carrier groups, buffer components, handguards, and related parts allow builders to configure AR-9 platforms around the operating requirements of a pistol caliber carbine.

Aftermarket Parts for Glock^® Pistols

Arm or Ally carries a wide selection of aftermarket parts for Glock^® pistols, organized around popular models and major component groups.

Our Glock^® categories include aftermarket slides, barrels, sights, triggers, and small components for platforms including the Glock^® 17, Glock^® 19, Glock^® 26, Glock^® 43, and other supported models. Model, generation, optic cut, barrel configuration, and individual manufacturer specifications should always be considered when selecting compatible components.

Aftermarket Parts for SIG Sauer P365 Pistols

Arm or Ally also carries aftermarket parts for SIG Sauer P365 pistols, with a growing selection focused on the highly modular P365 family. These components support popular configurations including the P365, P365X, P365XL, and P365 XMacro platforms where manufacturer fitment specifies compatibility.

Our SIG Sauer selection includes aftermarket slides for SIG Sauer P365 pistols in different configurations, finishes, and optic-cut arrangements, along with aftermarket SIG P365 and P365XL barrels available in model-specific lengths and configurations.

The modular design of the P365 family makes correct component identification particularly important. Slide length, barrel length, optic footprint, loaded chamber indicator configuration, and specific P365 variant can all affect compatibility. Our dedicated SIG Sauer categories organize these components by product type to make model and configuration differences easier to identify.

Reloading Supplies and Components

Reloading allows shooters to control component selection and cartridge configuration for accuracy, consistency, specialized applications, and repeatable ammunition production. Our inventory of reloading supplies covers the primary components and equipment used throughout the reloading process.

From brass and bullets to primers, smokeless powder, and reloading equipment, Arm or Ally supports reloaders working with popular rifle and pistol cartridges as well as specialized precision applications.

Technical Resources and Build Knowledge

Component compatibility, platform differences, optic footprints, barrel specifications, and reloading terminology can become complex as configurations become more specialized. Our Tactical Intelligence resource hub provides detailed articles covering AR platforms, Glock^® components, SIG Sauer P365 topics, component selection, compatibility, and reloading information.

Arm or Ally combines an extensive component catalog with technical resources designed to help builders and reloaders better understand the platforms and components they work with.

Arm or Ally — Build it right. Shoot it better. Ready when you AR.