If they pass, the agents they send to collect them will die. They may have thousands of agents but I guarantee you that that’s not enough.
Estimates vary, but there are 100s of millions of firearms in the US. Call it 200 million. Say the average weapon weighs 5 lbs (pistols/rifles/whatevers).
This cook calculates that to be about 1e+9 lbs of firearms, at least.
Put 50K lbs on a trailer, and it would take 20,000 tractor trailers to move them.
Someone can't do math, but we knew that about liberals.