I agree. I had a TASO Spartan years ago, which had threaded barrels. The threads were similar to, but not, 'Cocker. I never measured/gaged it back then, but I was led to understand it was a thread unique to the Spartan and Vindicator.
If you'd like, I could cut you a custom barrel for it, either rethreading an existing barrel (if one can be found with sufficient 'meat' to it) or making a from-scratch Freak back, for example.
I'd need the body to measure and fit, but otherwise it's a straightforward mod.