I was wondering what would be the timeframe for the use of Primitive Tech in the bigger Periphery States?
Era Digest: Age of War has the exact dates of production for these states. The Primitives were still being produced into the 2500s, though every Periphery Power was capable of producing modern BattleMechs by this point.
The earliest date of production would be 2474 for RWR and 2471 for the TC. It's unknown whether some of the Hegemony's units were licensed out as they became obsolete, but there is little evidence of this. States were highly unlikely to export their designs, as these were all seen as cutting edge material intended to provide a huge advantage in combat. One could assume at this time each state produced the MSK-6S.
- The Rim Worlds Republic produced the modern Primitive ancestor of the
Phoenix in 2471. They introduced modern (non-Primitive) tech in 2503 and the modern PX-3R in 2521.
- The Taurian Concordat produced the TR-A-1 back in 2481, finalizing the modern version (TR-A-6) in 2548. They introduced modern (non-Primitive) tech in 2505.
When is the "final" date? It's unlikely there is a universal date, since Primitives were likely to be available for some time into the Star League era. Although RATs are a very poor indicator of canon production, the
Historical: Reunification War tables tell us that every House and Periphery Power heavily utilized Primitives until the end of the war.
It's likely that they continued in production in the early part of the 2600s as well, as the states re-armed. I would conceivably have them as "available" into the mid-2600s for Periphery Powers and end their use right after the Reunification War for the Great Houses.