When I lived in Colorado, back in the early 1980's, a friend named Kevin (resident alien from N. Zealand) who worked for the mines in NW CO was a freelance demolition guy. Probably no longer possible, but he accumulated large quantities of explosives, mostly low grade stuff and dynamite, to the extent that a lot of it was old and "leaky" (he had one of those small construction "office" trailers stacked to the top with explosives of every kind). Being an alcoholic, and from NZ, he just laughed off the leaky dynamite (I think being brave/crazy/reckless and a heavy drinker might be some kind of competition between New Zealanders and Aussies). He did a lot of crazy things, and finally got deported for tying 1/4 - 1/2 sized sticks of dynamite in trees, and shooting at them to scare trespassers off the 7000 acres he also acted as caretaker for. When unknown persons would come near his dynamite targets, he would take a .22 rifle and strike the partial stick with a .22 bullet. Apparently, the effect was like a law rocket had hit the tree. He finally scared the crap out of someone who DID report it to the local sheriff's dept, and that was the end of that. So, yes, a high impact WILL detonate dynamite.