Why are people thinking he has any resemblance of a 20th level character?
A fine target has an AC of 13 or 18 if it's moving. A first level PC can hit this without too much difficulty.
He can shoot fast. This doesn't mean he is high level. The game doesn't care about fire rate too much. If there were a video of someone shooting a target 6+ times with 2 guns, does that mean +16/+11/+6/+1 base with rapid shot and all the 2 weapon fighting feats with at least 19 dex? No.
He doesn't have deflect/snatch arrows, because that would mean he can catch bullets.
Since high level equals high CR, that would mean a dire crocodile (a CR 9 monster that's large enough to swallow elephants and killer whales whole) isn't even half the CR of this person.