Cheap extra weight for practice, etc.

[NorthernCaliforniaHunter]

For what it's worth, I noticed something interesting last night:

A .30 Carbine shell slips right over the end of my carbon arrows. I drilled out the spent primer with a whole large enough for the threaded part of my field tips to insert through and viola! 50 extra grains to add or remove without affecting the penetrating profile (the base of the field tips is the same diameter as the outside of the spent cartridge.)