It appears the 5.7 x28 is being singled out by the administration for it's next big anti-gun attack.
Having failed on their ban of 556 Green tip plan--
the new plan is to label the 5.7 and its associated handgun as a " destructive device".

As with the Street-Sweeper (which is by most standards was a poorly crafted windup (nearly a)toy weapon).

The insipient plan is the 5.7 first, using the emotions of FT. Hood and "cop-killing vest penetrating bullets" non-sporting purpose angle---
then-
attack all "rifle caliber" pistols in a step by step maneuver.

Made a bit of money the last try on SS109 and M855.

I just don't have any 5.7x28. to bad when prices double or more it is time to sell