Re: One hell of a boat tail.
It takes a tremendous amount of force to set of the incendiary. The incendiary is lit by the friction generated as the AP part of the projectile begins to disrupt forward as the bullet strikes a hard object. Stated another way, for the incendiary to ignite, the jacket of the bullet must strike an object hard enough to begin to displace the AP inside of it. For example, if you shoot a 55 gallon drum it punches through the outer drum wall and flash-bangs inside the drum, then the penetrator continues on out the other side into the next county. I've shot these through mesquite trees and 250 lb pigs and they don't go off until striking something hard on the far side. I'll fire these 3 off and see how they do and then probably switch to just AP, no "I". You are right though, why risk it. It's so dry here I certainly don't want them to trace.
I've thought about doing subs with a custom can but I've got so many other logs on the fire. Waiting on my form 1 for my SBR 300 black/whisper, and have a form 4 pending on another 9mm can. Maybe some day.