The only reason to mention the seven days is to keep trying to pass the “cooling off” period when you buy a firearm. The “toughest” cooling off is the 10 day California law which should appeal to the Moms as the Socialist Bear State is mentioned many times as the jewel crown of Gun Control. I guess Asshole Connor Sturgeon would have not taking victims on day 11 of the purchase after planning for months to commit his rampage?
A sufficiently nutty nutjob can stay nutty longer than any given waiting period. Some of the murderers plan for months or years.
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All the waiting period does otherwise, is cost people twice as much time and travel to get a gun. (and with gas prices today, in rural areas that latter can really hurt.)