Caliber specific insert for the Bison Armory Bore Cleaning Extender!
Select from .223/5.56mm and .308/7.62mm. Other calibers coming soon, including .243/6mm, .264/6.5mm, .277/6.8mm, and .284/7mm.
Made to match SAAMI specified groove diameter.
Keeps the patch from blooming and maintains the stress on bore brush bristles as they pass out of the bore through the muzzle.
For bore brushes: Push the brush all the way out of the extension and pull back through to fully pre-stress the bristles before they go into the barrel.
For patches: Push fully into the insert but not out of it. The patch can be pulled back through to get complete strokes past the muzzle.
ALWAYS USE A CHAMBER GUIDE TO PROTECT THE CHAMBER AND TO KEEP THE BRUSH OR PATCH ALIGNED IN THE BORE!
Extends the bore to protect it where it matters most at the muzzle.
Allows complete strokes past the muzzle with bore brushes and patches so that the bore is cleaned the same at the muzzle as it is the throughout the rest of the bore.
Allows you to pull the bore brush or patch back through the muzzle for multiple complete passes.
Works great to condition the bore with J-B, Iosso, and other abrasive bore cleaners.
Protects the bore at the muzzle when using a bore scope.