I have not heard of any aftermarket barrels yet.
As for loading the 22 TCM, itís really easy, just like loading a rifle round and requires some prep work, trimming the case and lubrication before loading. The dies are hard to come by, I bought my set at the right time, and the shells are not that easy to find either, however it's becoming a popular round and more die mfr will add it to their line in the future. It runs very well with W296, 40gr bullet and a small pistol primer (donít need a magnum)
At the range people think I'm shooting a 44mag because of the huge kaboom and very large muzzle blast.
Just follow the link and you can get a lot of good reloading tips and setup for the 22 TCM. I show how to set up the Dillon 550b with the TCM dies. on page 4.