You will note that the shrapnel on the Haymarket bombing token does not show through on the other side. Just lay the planchet in the press, drop a piece of shrapnel on it, and strike the piece - the extra piece is embedded in the token.

With regard to bomb-related numismatics, aside from the often-seen Haymarket Riot bomb relic 1886 token, I distinctly recall and physically handled a 1917-dated gold multi-part suspension pinback badge , approximately 3" in length with a center mounted diamond, awarded (engraved) to a Los Angeles police officer for apprehending an "anarchist" throwing a bomb in that city and saving lives. This was all in the engraved reverse inscription. It was in a Stack's auction perhaps twenty years ago or sold by Tony Terranova to the late Seymour ("Sy") Finkelstein of New York City and Jupiter, Florida, a good friend. It is still in his significant numismatic estate.

Apparently bomb-throwing anarchists plagued the U.S. around the year 1917 from my knowledge of US history, doubtless brought on by the mob-induced anarchy in Russia at the time which created the Communist regime.