Re-inserting a magazing into a Ruger Mark III can sometimes be a bit tricky. But the Plus 1 PRO Magazine Bumper from TANDEMKROSS not only fixed that issue, but also gives you one more round in the magazine. Video: Installing TANDEMKROSS Plus 1 PRO Magazine Bumper: Ruger Mark ...This entry was posted in Guns Product Reviews Videos and tagged 22/45 22/45 Lite magazine Mark III Ruger Ruger MK III TANDEMKROSS Upgrade on April 26, 2015 by Steve Jenkins