Fifty-year-old John Grzyminski pleaded guilty Monday to charges related to three homemade explosive devices found at his Warrington home in May.
Grzyminski told the court he intended the explosives to be "very large firecrackers."
Grzyminski's mother called police after finding the devices after a May 9 argument. Bomb squad officers detonated the devices after clearing residents from a few nearby homes.
Grzyminski said after his arrest that the explosives were meant to scare bears but he said Monday he made that story up.
Sentencing is scheduled for Jan. 4.