Nice choice. The tagmaster is the poor man's Phantom....
It's the same threading at the ACI Maverick and the PMI Traccer. Sadly it's not a common thread but with a bit of patience and hunting you can find some Taso and Lapco barrels to fit.
It'll be listed as a PMI Trracer thread or ACI Maverick thread. At least the odd one I've seen listed is shown as that.
No fear though. The stock barrel actually shoots really straight and consistent if you feed it decent paint. I've used my own Tagmaster with electrical tape "wedgits" to avoid rollouts and it was surprisingly good. But it's more loud than a ported barrel. Got quite the POP to it. But not as bad as some.
There was also a guy around somewhere that drilled a small hole in the barrel between the threading and the shoulder that meets the body and sticks a short 1 inch length of knitting yarn into the hole so about 1/2 to 5/8 inch of yarn is inside. Says it makes a nice anti rollout solution. The yarn would likely wear away and only last a day but that seems pretty sweet to me. I want to find a spare barrel to try it on first though so I don't drill my only barrel and find out that it was a mistake.