In this video I replace the detent on a VM-68. The feed detents on VM-68s are sometime referred to as Magic Fingers and the detent I am replacing the stock detent with it from a Miltec Blowback and is made to the same dimensions as the stock vm detent.
These detents are available here:
In the video I mention the feed block does not need to be removed from the VM-68 to replace the feed. You can just remove the detent plate with the feed block still attached and change a broken detent.
Other VM-68 parts are available on www.baccipaintball.com here: