Nah, that's an inert "pineapple" training grenade. He'd hurt himself with anything more deadly.
And 14 weapons is an "arsenal"? I'd call that a "starter collection".
I wish I had the secret liberal decoder ring that explains the differences between arsenal, stockpile, hoard, armory, depot, and "a lot of guns". I'm trying to figure out where I stand in the standings.
Note to self: Do NOT bite FBI agents.