This anime is such shit, lol. We are always shown how Kirito is THE best sword fighter. And out of nowhere, this guy pwns Kirito? Makes no sense. Of all the possible developments, this one makes the least sense. Seriously, Kirito has been blocking bullets for 10 episodes, and now this? As Kraco says, there´s no reason to believe he´d be rusty in terms of sword skills.
Most interesting piece of information, though, was Death Gun replying to Kirito´s explanation for Death Gun´s crimes, "you have a fascinating imagination". Maybe I´m being optimistic here, but imo this wording implies that Death Gun finds Kirito´s reasoning funny, further implying that it´s 100% wrong. To be honest, at this point in the story I´d prefer if it turns out that Death Gun truly CAN kill people with his gun alone after all. Putting this ridiculous "partner who´s driving around whole of Japan, using superior lock-picking skills to inject poison into victims´ bodies" bs. No idea how it´d be explained then, but idc.
As for the sniper duel, dear god, for a moment I feared they´d go full-retard and have the bullets hit each other in mid-air. Would have been soooo corny.