The Otis FG246 B.O.N.E Tool is a purpose-built cleaning tool designed specifically for 5.56mm AR-platform rifles. If you shoot an MSR or AR in .223/5.56mm, .300 Blackout, or .350 Legend, this tool targets one of the dirtiest parts of your rifle: the bolt carrier assembly. Unlike general-purpose bore cleaners, the B.O.N.E Tool gets into the tight spaces where carbon and fouling accumulate on your bolt carrier and firing pin—areas that standard rod-and-brush cleaning can miss.

Built from steel and measuring 5 inches long, this tool features an 8-32 threaded hole that lets you attach a T-handle or rod for leverage and control. That threading also makes it compatible with standard cleaning rod attachments, giving you flexibility in how you work it. It's a straightforward, no-nonsense addition to your range bag or cleaning kit—the kind of thing that makes post-range teardown faster and more effective.

One thing to keep in mind: bolt carrier dimensions vary slightly between manufacturers, so while this tool works flawlessly with many bolts, fit can vary from one brand to another. A quick test before you need it for serious cleaning will tell you how well it meshes with your specific rifle. If you run an AR platform rifle regularly, especially if you shoot suppressed or push higher round counts between cleanings, having a dedicated bolt carrier cleaning tool cuts your maintenance time and helps keep your action running smooth.

The Otis FG246 B.O.N.E Tool is a purpose-built cleaning tool designed specifically for 5.56mm AR-platform rifles. If you shoot an MSR or AR in .223/5.56mm, .300 Blackout, or .350 Legend, this tool targets one of the dirtiest parts of your rifle: the bolt carrier assembly. Unlike general-purpose bore cleaners, the B.O.N.E Tool gets into the tight spaces where carbon and fouling accumulate on your bolt carrier and firing pin—areas that standard rod-and-brush cleaning can miss.

Built from steel and measuring 5 inches long, this tool features an 8-32 threaded hole that lets you attach a T-handle or rod for leverage and control. That threading also makes it compatible with standard cleaning rod attachments, giving you flexibility in how you work it. It's a straightforward, no-nonsense addition to your range bag or cleaning kit—the kind of thing that makes post-range teardown faster and more effective.

One thing to keep in mind: bolt carrier dimensions vary slightly between manufacturers, so while this tool works flawlessly with many bolts, fit can vary from one brand to another. A quick test before you need it for serious cleaning will tell you how well it meshes with your specific rifle. If you run an AR platform rifle regularly, especially if you shoot suppressed or push higher round counts between cleanings, having a dedicated bolt carrier cleaning tool cuts your maintenance time and helps keep your action running smooth.