How to Increase Your Arrow’s Penetration with Weed-Whacker Line

Heavy arrows penetrate better than lighter ones, and this handy DIY hack can help

A side-by-side comparison of an arrow that weighs 438.4 grains on a scale, and the same arrow that weighs 563.0 grains on the scale after adding weed whacker line.
Arrow weight before (left) and after adding weed wacker line to the shafts.Tyler Freel

A large portion of the archery world has been obsessed with speed for quite a while now, and that obsession has led to many bows that shoot well over 300 fps. In my experience, however, one huge factor of arrow penetration is arrow weight. Heavy arrows penetrate better that light arrows. The pendulum is starting to swing back, and I’m seeing a lot more folks opting for much heavier arrows, which are slightly slower. Sure, you have to adjust your sights for shooting, but the increased penetration is worth it for them.

There are several ways you can increase arrow weight. One way is by adding heavier points. But when you increase the weight on the front of a tuned set of arrows, it changes the dynamic spine, making your arrows flex more during the shot and altering their flight.

One of the easiest ways to add some thump to your setup—without changing the spine of your arrows—is to add internal weight. You can buy commercially-made weight tubing that fits inside your arrow and adds significant weight without altering the flexibility of the arrow. But there’s an easier, cheaper way: You can use plastic weed whacker line to do the same thing.

A broadhead with three strands of weed wacker line wedged in it, on a wooden table beside a scale.
The author's buddy was able to fit three strands of weed wacker inside his arrow.Tyler Freel

To prepare for his muskox hunt this week, my buddy Nick did this for his arrow setup. He was able to fit three strands of line inside the arrow shafts. They ran the full length of the shafts and increased his arrow weight from a solid 438 grains to a bone-crushing 563 grains: an increase of about 29 percent. This weight slowed the arrows a little bit, but they still fly like darts.

If you’re wondering how a heavier arrow will perform on game, give this cheap, easy method a try this season. Hopefully by the time you read this, there will already be a muskox on the ground that can testify to its effectiveness.