TANDEMKROSS Bolt Keeper Extended Bolt Stop (Ruger Mark IV 22/45)

The factory bolt stop on a Mark IV is a thin lever that gives the thumb almost nothing to push against, which is a nuisance every time a shooter locks the bolt back or releases it on a fresh magazine. The Bolt Keeper replaces it with a wider lever carrying a horizontal step cut, so the thumb lands on a shelf instead of skating off an edge.

The more interesting feature is the key-hole lock. On a Mark IV the bolt stop is free to migrate once the grip comes off, which is how the part ends up on the bench floor during a cleaning. TANDEMKROSS machined a locking feature into the Bolt Keeper that secures it in place while the grip is removed, so a routine strip stops being a scavenger hunt.

TANDEMKROSS lists fitment as the Ruger Mark IV 22/45 and the company's Cthulhu aluminum frames only. It is made in the USA from lightweight aircraft grade aluminum, installs in minutes, and comes in red or black.