I believe I have narrowed down my mechanical BH choices to launch from my TP Viper S400. In the running are the Grim Reaper 3 blade razor tip 1.5" cut, the Muzzy HBX Hybrid 4 blade 1-5/8" cut, The Auto Lock mechanicals with a 1.7" cut, and finally the TruGlo Titanium X 4 blade with a 1-3/4 cutting diameter. I chose these four offerings because of the fact that there is no collar or band needed to keep them closed during flight from a 400 FPS or faster XB. They all also offer replacement blade kits and available practice point configurations with the exception of the TruGlo, which doesn't offer a practice head option. I thought about Rage, but the whole collar thing is a PITA to me. Any thoughts, experiences, or suggestions from anyone? I am always open to learning about better options through others' experiences in the field. Knowledge is king!