Also, there is no such thing as an "84mm caliber". It's either 84mm or XXX caliber, it can't be both. The fact that the TSA put out that tweet with a glaring error like that in it shows that they have no idea what they're doing.
Many years ago I had a young acquaintance who thought he was a real Rambo, unfortunately he couldn’t tell the difference between a 38 and a 50 cal.
He was also a real IDIOT.
He got a job with TSA at LAX!