Anyone have any reasons good or bad about this caliber. Cartridges, twist rates, and fps data would help too.

Thanks in advance,

Downsides would be limited choices and inconsistant delivery on bullets, cleaning supplies and barrels, as I believe only one guy is or perhaps was making them.

There are certainly a few guys that just have to have something different, but to me the 17 is the smallest practical round at this point.

You may want to e-mail Todd Kindler from Small Caliber News, he posts over on the small bore forum on occasion.