On Tue, 18 Sep 2018 13:30:39 +0000 (UTC), danny burstein
wrote:

In Terry Coombs writes:

What's that light duty explosive that shooters use
on their targets when they're hundreds of feet away
to give them a very visible and audible sign they've
aimed correctly?

Tannerite ?

Ah, that's it. Thanks.

You have to detonate it :-)

"... two separate components that are mixed by the user. The
combination is relatively stable when subjected to forces less severe
than a high-velocity bullet impact, such as a hammer blow, being
dropped, or impact from a low-velocity bullet or shotgun blast. It is
also designed to be non-flammable[3] — the reaction cannot be
triggered by a burning fuse or electricity."

https://en.wikipedia.org/wiki/Tannerite_(rifle_targets)

Hold my beer, watch this