I have a few rounds that need to be discarded; please help me do it the right way.  
Thanks,
L.P.

shoot them!

or, if they're not safe to shoot, buy one of those little hammer thingies to dis-assemble rounds -- leaving you with only the primed case as a real problem; the powder can be burned (open area, nothing flamable around) and the bullet itself can be thrown away.  Not sure what to do with the primed case though....

FOTBR

I have this problem as well, a number of dented .223 rounds from bad mags and teething of a new AR-  I've wondered if dropping them in a coffee can with oil or some other substance for a long time would neutralize them.

one more vote for disassembling them.

You can have fun with the rounds by taking the bullet out and pouring the powder in the toilet. And then make a necklace with the useless round =)

Buy a bullet puller from Brownells.  Dump the powder in the toilet, or burn it in a metal can (it will burn, not blow up) if you are bored.  You can chamber the now empty round and "snap the cap", you will hear a small pop as the primer fires.  The gun will not cycle, you will need to manually extract the case.

KingOfTheBumps has the right idea, almost.

Pull down the bullets, fire the primers in a gun, and as for the powder...make a small pile of it outside in a safe location, well away from anything you don't want to burn down, run a trail of the powder out several inches from the main piles,  light the trail, back up, and watch the fireshow.
Especially fun at night.

No, smokeless powder won't explode under these conditions unless it's confined or the pile is WAY too big.   A handful of powder is about right for one pile, and quite safe to burn.  I've disposed of quite a bit of old, bad, or unknown powder this way.

There is no benefit to flushing powder down the toilet.   I can't see that it'd do any good for anyone at the water treatment plant,  and throwing it in the trash presents a very slight hazard of causing a garbage truck to burn down.
Just burn it in your barbecue grill and be done with it.  

CJ

After dumping the powder, you can deactivate the primer by spraying it with WD40.  It won't take long at all for this to kill it.

I wouldn't just snap the primer in the bore, unless you plan on cleaning the bore afterwards.  Lot's of crap in that primer you don't want sitting in your rifle.

thanks brou!  I was wondering how you could 'kill' primers without snapping them in a gun; like you said, that's pretty dirty (did it to a handfull of cases, took a LOT of cleaning to get rid of all that crap, so I didn't want to recommend that)

After spraying the primers with wd40, is there any way to visibly tell if their dead?  or just spray them and throw them away?

-FOTBR

I'd spray both inside and out, then allow it to set for a day or so.  There's no way to tell except to try one out.

Do what the Russians were doing!

Spread the powder on your lawn, its a high Nitrogen fertilizer.

I second the disassembly motion.
Or just go out to the boonies, throw all the ammo in a bag with gasoline-soaked rags, light the bag, throw it behind a rootwad/dry creek bed/arroyo and fugetaboutit.  

This comes up about once a year at work for me.

The best answer? Give it to ATF, who burns it in a special container.

As a local PD, we get hundreds to thousands of rounds of ammo turned in every year by folks who find it or encounter it when cleaning their houses, as well as ammo seized with weapons. We also get lots of pyrotechnics for some reason, that GIs and the national guard dump at a rest areas on their way to and from a major military base here.

Most of this is stuff you just wouldn't want to shoot. Bulging shotgun shells. Corroded pistol ammo. .30-06 with hand painted tips in all sorts of funky colors.

We let the Evidence Tech go through the pile first. He runs a ballistics lab and is always looking for weird loads and calibers for his sample files.

Next up, we let the pistol team go through and see if there are any decent looking rounds for practice. A couple of those folks collect old ammo, as well, and we have had 80-90 year-old ammo boxes and paper and brass shotgun rounds show up occasionally. Pyro goes to SWAT or K9 to use in training.

Everything else gets gathered up and taken to ATF, who, once every year or so, has a special "Burn" container come around to destroy ammo that cannot be safely re-used. Before anyone gets too upset, this is really nasty ammo; I would not shoot it in any of my weapons, and the expense and effort of setting up an auction is not worth what little money we would recoup. Because much of this stuff is of unknown origin, there would also be much liability (the scariest word in police work) if we gave the stuff away.

1. Disassemble the round.
2. Use bullet for reloading.
3. Spread powder on lawn.
4. Place a couple drops of 3-in-1 oil
  in case to deactivate primer.
5. Bring bad/damaged & DEACTIVATED brass to
  junk yard.
6. Get a couple bucks from the junk man
  (depending on weight of brass).
7. Buy more ammo.

(I usually save up my bad brass in a large coffee can, and when I get 10-20 lbs, cash it in.)

I have about 300 rounds of 1948 vintage .303 ammo. This stuff hangfires regularly.  I first started to disassemble it for components, but the cases are Berdan primed, and the projectiles are A) steel-jacketed, and B) about .309-.310" in diameter instead of .311".  The loads I've made with these bullets leave a great deal to be desired in terms of accuracy.

There's a "hazardous waste disposal station" near my house that accepts all kinds of nasty stuff.  I'll probably be disposing of it there shortly.