American Built Arms Company AR-15 Small Parts Kit Features The American Built Arms Company AR-15 Small Parts Kit covers the components inside an AR-15 bolt carrier group that see the most wear and are most easily lost during field stripping and cleaning. The firing pin retaining pin ejector ejector spring and ejector pin work together to ensure spent casings are reliably thrown clear of the ejection port on every cycle a function critical to keeping the rifle running without malfunctions. The extractor spring with insert and extractor axle support the extractor s job of pulling the spent casing from the chamber another area where a worn or damaged part can quickly cause reliability issues. Having these parts available as a set means an owner does not need to source them individually when something wears out or goes missing. Rounding out the kit are three gas rings and the donut style O-ring both of which seal and support the bolt within the carrier during the gas system s operation. Worn gas rings are a common and often overlooked cause of short stroking or inconsistent cycling in an AR-15 making their inclusion in this kit particularly useful for routine maintenance. Because these are small easily misplaced components keeping a spare kit on hand saves a trip to source individual parts when disassembling a bolt carrier group for cleaning or inspection. AR-15 owners building or maintaining their own rifles will find this kit a convenient way to keep critical small parts in reserve. American Built Arms Company AR-15 Small Parts Kit Specifications Manufacturer: American Built Arms Company Model: AR-15 Small Parts Kit Compatible Hosts: AR-15 Includes: Firing Pin Retaining Pin Ejector Ejector Spring Ejector Pin Extractor Spring with Insert Extractor Axle 3 Gas Rings Donut O-Ring Available At: GrabAGun