Kevin Krebs, 32, was first arrested during the "No Kings" rally in West Chester on June 14 for carrying a gun without a license.
His home in Malvern, Chester County, was searched two days later, where authorities found pipe bombs and tactical gear.
7 pipe bombs found in home of man accused of carrying weapons at West Chester rally: Police
Authorities also found a military-style radio, night-vision goggles, and a gas mask in his vehicle.
Krebs faces up to 10 years in prison when he's sentenced on March 31.