The point is that if the bad guys don't have guns, those police would have been be alive.
True, however up until he died, legally speaking he was stilt a good guy (just like most of the rest of the American population... having not been convicted of any crimes or subject to any other legal process which would prevent him from buying a firearm (just like most of the rest of the American population who do not use firearms for evil. Had the military properly discharged him in a non honorable way (as it sounds like was their intention) then he wouldn't have been able to purchase something... so again, maybe it wasn't the gun which was to blame?
Guns are not like marijuana.
I live in Washington state... it's actually easier for me to buy marijuana than firearms (pot shops being closer to my house than stores which sell firearms or ammo... granted I can at least have ammo shipped to my house).
Block gunpowder and anything that contains it, and the gun problem is over.
Not quite, it just means those who own firearms aren't going to be shooting them as often, but will still likely have quite an inventory of ammo on hand.
More so, do you know what gunpowder is made of? Just some common ingredients one can purchase at your local home improvement store and/or grocery store... are you saying finding sulfur, charcoal, and potassium nitrate is going to be that hard?
You can't grow gunpowder and brass in your yard.
Who says you need to grow it? As discussed, you can make your own gunpowder as the component materials are not at all hard to come across, hell, there was a Star Trek episode which pointed out just how easy it was: https://en.wikipedia.org/wiki/...
There also is an entire class of firearm owners who reload their own ammo. Most simply combine over the counter brass, powder & bullets to make their own... I do know a few though who actually fabricate their own bullets & powder. In order to stop these people you'd actually have to crack down on primers... the chemistry & mechanics of which is a hair bit more difficult than powder, but not insurmountable.