Some police agencies and years ago some Federal agencies used to sell or trade in their guns when they upgraded to a different model or when they figured some of them were getting worn out.
This saved the taxpayer money because the sale or trade in would reduce the cost of the new guns.
Now days, due to political correctness most LE departments destroy their guns so they can't be used by evil criminals, also known as the taxpayers.
So, in some cases they cut them up like these, and in others so someone can't even salvage a hammer or trigger, they run them through a metal grinding machine that chops them into small pieces.
That's what Bill Clinton ordered done with a lot of M1 Rifles, Carbines, and a lot of .22LR Remington 513T, Remington 40X .22's, and Winchester 52D .22 target rifles.
You know, those favorite weapons of drug dealers.
In that case they were run through a machine nicknamed "Captain Crunch".
The point is, they don't want the taxpayer being able to acquire guns they paid for, paid to have destroyed, and would have paid for a second time if we were allowed to buy them.