Thoughts?
Same stuff the shoe bomber used or tried.....semtex, dupont, ensign bickford, royal ordnance, etc all use it as a primary. ANFO is a .60, Military Dynamite is .80, TNT is 1.0 and C-4 is 1.34 on the relative equivalency scale and PETN is 1.66 on same scale before you get into insensitive / sensitive exotics used in nukes etc ....
You can get this in a medical form, from cannibalizing uxo on a battle field or by stripping det cord.
Last but not least you can buy it, say you blew up 30 pounds of it , keep 10 pounds for yer buddies......common in military and construction to keep a little around for “emergencies”........
I read that somewhere........;o)