Modern-day crossbows produce jaw-dropping speed, and as mentioned multiple times in this article, GPI shouldn’t be toyed with. Speed is inviting but never jeopardize safety to obtain it. If you’re all about seeing a radar-busting fps flash across the screen of your chronograph, go with the minimum recommended GPI rating for the crossbow you’re shooting. However, don’t expect precision accuracy, and if that ultra-light carbon bolt his heavy-bone, penetration can quickly be thwarted. When hunting North American big game like elk and moose, I recommend a minimum bolt weight of 400 grains. When hunting medium-sized game like deer and black bear, you can get away with a slightly lighter bolt.