When you're through getting teased by old Walter (the brown trout) and are ready to play hardball, here is an extreme option ... .22 caliber, tied to a #10 hook with 6/0 floss and chenille. "Because I work with rimfire ammo, it's important to keep the chenille wrapped in the middle of the fly, or else it won't go off when the trout bites the rim," explains Fink, noting that one chomp in the right place at the right time might very well blow the trout's mind. "When tying bullet flies, you also need to use Kevlar thread; that's just playing it safe," he adds.