It is clear that Snatch Arrows works on non-siege firearms such as automatic energy fire from a Laser Rifle or regular bullets from a Maxim M1910.

It is also clear that Throw Back Arrows does not work on bullets from the latter, as the feat specifies that bullets are not ranged ammunition (which is weird, and seems to contradict the equipment section, but it's what it says).

Throw Back Arrows does not address, however, whether other, non-bullet, firearm-based attacks capturable via Snatch Arrows are supposed to never be considered ammunition. How does this work? Furthermore, if it did work, would the Automatic weapon quality still apply to the attack as used by the throwing-back creature?