The Tipton Universal Bore Guide Will Help Protect The Bore And Action Of Your Rifle By Properly Aligning The Cleaning Rod And Reducing Solvent Overflow. Cleaning Without A Bore Guide Can Allow The Rod To Bow And Rub Or Gouge Chamber And Throat Of The Bore Causing Real Damage And Loss Of Accuracy. Keeping The Rod Properly Aligned Not Only Protects Your Barrel, It Directs The Force Exerted On The Cleaning Rod Handle Allowing Tight Patches To Be Pushed More Easily.Protects Chamber And Bore Form DamageEnsures Proper Rod Alignment For Easier CleaningReduces Solvent Leakage Into GunS ActionAnodized Aluminum Tube For DurabilityIntegrated Solvent PortFits Most Bolt Action Rifles And Ar-15SInserts And Secures Into The Bolt PositionCompatible With Cleaning Rods Up To .425 DiameterAdjustable Position Sliding Collar For Bolt Actions Works With Most Centerfire Rifles, Fits Bolt Diameters .695 Or LargerAr-15 Collar Fits Securely Inside Receiver Of Ar-15 Style RiflesThree Interchangeable Tips Cover Most Calibers From .17 To .460Small: Most Cartridges .17-.24 (Up To 6Mm)Medium: Most Cartridges .25-.30 (6.5Mm- 7.62Mm)Large: Most Cartridges Over .30 (Over7.62Mm)