[aggie4231]

Is it possible to replace a gen 1 barrel with a gen 2 barrel?

 

[850sub]

Possibly. Call the factory to find out for sure. I know the handguard will swap, but haven't heard if barrel assemblies will swap between generations. Besides, I'm not even sure you can buy barrels. They quit selling the gen 1 barrels years ago. IIRC.

 

[TSB]

They replaced barrels on the Sub9/40 with gen1 Sub2k barrels, so they might support the gen1 Sub2k in the same manner and use the gen2 barrels to do warranty work. It's hard to say until it happens, though. (Sub9/40 with Sub2k barrel/fs/buttstock Pic for reference)