Millions are out there:.

"As of 2012, there are an estimated 2.5–3.7 million rifles from just the AR-15 family of rifles in civilian use in the United States; the total number of assault weapons in the United States among all types is not known, and can not be known because of the different definitions in different jurisdictions."
https://en.m.wikipedia.org/wiki/Assault_weapon.

Voluntary buybacks will fail, as the most dangerous, paranoid owners will keep them.

Confiscation will only partly be effective and most likely lead to violence and a thriving
black market with criminals making fortunes. Think Prohibition.

We need to change our culture; that will take time and only be partly successful. We live
amidst a huge gun cult. It grew around us and now we are paying the price in deaths
and destruction with little recourse in the short term.

I had a beloved dog who was diagnosed with deadly tumor which could rupture at any time,
yet she was free of pain and fully enjoying her life. The vet explained that she could
live comfortably for many more months, but her death would be horrific.

His words still resonate: "Your animal companions give you deep love all their lives. In return, you
have the ability to give them the gift of a comfortable death."

After several days of anguish, I chose to say goodbye my precious dog while she was feeling well,
rather to risk her suffering.

His wise words have guided me during multiple end-stage crises with other animals.
It is always hard to accept the responsibility, especially the timing, and yet is something
we can give our animals we cannot give our human loved ones during their exit.
And for this, I am grateful.