I've seen those online, but nowhere locally. I would/will by one, if the price is OK.
Should be good for ~2700fps out of a bolt action 22" barrel I'd guess, with somewhat less noise than a Hornet and about 1/2 the powder consumption
Not too sure about the availability of 5.7x28 brass and dies
Now available...
SS197SR ammo (5.7x28mm)... 2,000 round case @ $1,349.99
(50 rounds per box / 40 boxes per case = 2,000 rounds per case)
https://shopquestar.com/shopping65/shopexd.asp?id=1707&bc=no