[MadMax]

I think the TK grooving would either be swaged or broached.

Swaging would involve pulling a tool down the barrel which deforms the material to form the shape. The tool would have helixed lobes and would be rotated as it'd drawn down the barrel.

Broaching uses a progression of cutting edges to shave the profile. The forwardmost (first) cutter removes say only 0.002" of metal and the one behind takes another thin chip. A progression of 5 cutting edges could remove 0.01" of metal per pull which sounds about how much a TK barrel needs. After broaching, a polishing stage would be required to take off the burrs and clean up the cut surfaces. I wouldn't be surprised if polishing could be accomplished by pumping an abrasive paste thru the barrel for awhile.

If TK was uber advanced, they could be using an electrical discharge technique which ablates metal with electrical discharges. I kind of doubt that they're doing that though. It's an expensive slow process which is usually used for hard steels. I think Glock barrels are electrically ablated to form the rifling. With electrical ablation, you can do crazy stuff like progressive rifling which varies the helix angle from beginning to end. Start with a gentle helix and end with a steeper one so you apply a more constant torque on the bullet as it accelerates down the barrel. SVI does that I think.