I am building one now and I was advised to epoxy in a single shot follower by a couple guys with quite a bit of knowledge on these. They also said that in a prairie dog shooting frenzy where 10 or more shots are taken in a string, a box of ammo next to the rifle might be just as fast one at a time if you consider the time spent shoving them down in a box mag. Just food for thought.
Grunig/Elmiger is a swiss match rifle company that chambers a CISM rifle in 6mmBR.
The magazine is a Sako TRG style with a follower that has a ramp built into the front of the magazine to facilitate feeding. I used to service these gems and they run like a raped ape. The website used to have pretty good photos of how it looked. Not sure anymore as it's been years since I fiddled with one.