A couple of years ago, I was tying flies at the Federation of Fly Fishermen's Fly Tiers Expo. During a break in my tying session, I wandered around the hall to see what other tiers were demonstrating to the throngs of fly-fishing enthusiasts.

To get the yarn tight for clipping, use a spent .30-caliber case with its primer removed. Photo by Dean Finnerty.

Another guide was tying a yarn fly that really caught my eye. It was similar to the Glo-Bug-style flies that have been around for years, but his one had a new twist, with these characteristics:

• Incredibly easy to put together,
• Super-durable.
• Had a snelled leader that let gear fishermen add a bait loop, so that the fly could also incorporate a variety of popular baits such as shrimp, prawn meat or roe.

I was hooked and immediately began mentally churning through a number of changes that I thought would make the fly an ideal addition to my fly arsenal for winter steelhead.

Without a doubt, it's the easiest and deadliest yarn fly I know of. Known as a Bullet Bug, its name is derived from the simple tool needed to form the very compact ball of yarn necessary in the fly's construction.

I use the plastic cap of a ballpoint pen with a hole drilled in the end, but others use a spent .30 caliber rifle cartridge with the primer removed.

To form this incredible little egg-imitation style fly, use the McFly Foam yarn, available at most fly shops around the country. McFly Foam comes in 45 shades that range from white to red, to pinks, orange and peach. You name it, they have it.

A package costs around $3 and lets you tie dozens of Bullet Bugs.

STEP BY STEP
Remove the McFly Foam from the package. Separate the individual strands. Place each one through a common beverage straw for ease in handling. To get the strand into a straw, run a monofilament loop through the straw, and then pull the strand of yarn through. Now you can handle the yarn much more easily.

Choose the primary color for your Bullet Bug. I prefer shades of pink, red or orange.

Now choose a contrasting color for the "eye" of the egg. I often use dark red or bright orange. If my primary color is pink, cut nine or 10 strands of pink McFly Foam yarn about 1 to 1 1/2 inches long. Place them next to one another in a small bundle.

Then cut a single strand of yarn of contrasting color and place it in the center of the bundle of primary-colored strands. Set it aside.

Next, take a 36-inch long piece of monofilament leader material. (I prefer 12- to 15-pound Maxima.) Tie a simple slipknot, like a Reel Knot or Arbor Knot, in one end of the leader.

Slip the bundle of yarn inside the slip-knotted loop in the monofilament leader and pull the slipknot up tight. The tighter, the better.

Next, run the leader's other end through the pen cap or de-primed rifle case, and pull the bundle of yarn just inside the opening of the case. The strands of yarn will become tightly compressed. Now, using a sharp pair of scissors, cut across the strands of yarn left sticking up out of the case.

Once you've cut across the strands of yarn, remove the bundle of strands from within the case. Because it's been pulled tightly into the cap and become very compressed, this can sometimes be hard to accomplish.

To get it free, I usually need to pick the cut bundle of yarn out of the cap with the tips of my scissors.

Next, place the bundle of McFly Foam yarn between your palms and roll it around a few times. This forms a perfect little round ball of yarn complete with an "eye," just like a fertilized salmon or steelhead egg.