The thundermug is an Enerpac RC256 25 Ton 10,000 psi Single-Acting Hydraulic Ram with the guts and hydraulic fitting removed. The cylinder walls were pitted and gouged so it was taken out of service but is otherwise structurally sound.
Thundermug loaded with 4 ounces of triple seven ffg and 1 pack of hamburger buns recorded on a gopro hero 3+ 1080@30fps
Thundermug loaded with 3 ounces of triple seven ffg and 1 pack of hamburger buns recorded on a canon xa10 1080@24p
The thunder mug was disabled and destroyed after approximately 100 shots to eliminate the possibility of catastrophic failure.
UPDATE: We found the first recorded thundermug shoot and wanted to add it. This video has a few f-bombs and such so NSFW:
