The lower the halo reading the more susceptible the tube is to recoil damage. Or any vibration damage for that matter really, even dropping it while it’s powered on. The ITT and L3 “WG” (weapon grade) tubes that I’ve seen are all higher halo tubes as well. Most of those being around 1.0-1.2 to be exact. The tube that came out of this 27 is a F9815 wg. I’m going to do a little estimate on the halo compared to other tubes when I get a chance. I have a couple Elbits with 1.0-1.1’s to test it beside. But yes, a .6 halo tube would make me nervous in a 27 for sure.
Jay