Sorry, ronnie gore, I disagree on several levels.
You could throw money in the trash, or...
Put them in the classifieds for $50 plus shipping and make certain that you state that they are reloads to be disassembled by the purchaser and are intended to be used as components only. Without a gun to fire them from, they are not dangerous, hazardous, or explosive. Put 'em in a small USPS flat rate box ($5.80), slap a ORM-D label on it and Bob's your
This sir is illegal. Easy to prove, prosecute, and get a conviction. New USPS Inspectors have to start somewhere, locking you up would be a relatively easy task.
The Domestic Mail Manual is available on-line, check these things before you get in trouble.
Some LE agencies will accept unwanted ammo and have their ordnance people dispose of it.