Wood arrows are my favorite for most of my shooting, but in some hunting situations the consistency and strength of carbon make it a better choice. I like to use 600+ grain arrows for hunting. Using brass inserts and heavy broadheads will help to increase the FOC, but my arrows still need additional weight that’s distributed throughout the shaft. Although heavy carbon shafts are available, there’s an easy way to put weight into the shafts you already own: using 1/4″ polyethylene braided rope.
First, remove the screw-in point and nock from the arrow. Next, run a very thin piece of wire from the front to the back of the shaft through the hole in the insert. If it’s clogged with glue, clean it with a small drill bit. Then measure a piece of rope that will add the desired weight. Melt the ends of the rope, then loop and twist the wire at the back (nock end) of the shaft through one end of the rope.
Lubricate the plastic rope with spray furniture wax, and push it into the nock end of the shaft as far as you can. It should be a sliding fit. When you can’t push it any farther, gently pull the wire at the other end of the shaft until the end of the rope is at the back of the insert. Pull the wire to break it off from the rope. Then, replace the point and nock.
The rope will slide back (and then forward) when you shoot and may even pop the nock off the shaft. If this happens, stuff the nock end of the shaft with thin plastic film (plastic food wrap or packaging “rope” works well) and reinstall the nock. This will stabilize the rope, but adds only a small amount of weight.
Since the entire process is reversible, you can tune your arrows with test shots and adjust the amount of rope accordingly. Polyester (core and sheath) rope will give you even more weight if you need it. This technique works with aluminum arrows as well. An article in an old TBM gave me the idea to use it with carbon arrows.