Don't know for certain but the action looks very similar to the Walther 1250 dominator, which is regulated.
It is also not the best peice of engineering I have ever seen. Currently palying with one as a project and not too impressed.
But as I say not seen a rotex in the flesh!
FTP900 +Sightron S111 10-50 x 55
AA Pro Target in FWB FP70 stock + MTC Mamba lite
Daystate Airwolf + Bushnell Elite 6500
" life is about the memories we hold and not the things that we own"