Wolverine MTW Wraith X CO2 Stock Wrench

With my setup I only have 2.5 rows of the knurling exposed, which made closing the cap fast enough rough sometimes, especially when my hands were wet. 

This wrench lets you get more leverage, just insert your capsule, get the threads started, pop the wench over the end of the cap, squeeze and twist.

The end of the prongs have a hole for paracord to help prevent loss/retain to gear.

It is important that you make sure your threads are engaged correctly before twisting with this wrench as you could mess up your threads with the additional torque

Make sure that your sliced file has at a minimum ridges where the splines are.