What are you going to do once the undead rise?

[Philly Mike]

note to mike: RPG's can't even travel a mile and they are way lighter than a chainsaw with a gallon and a half of gas. RPG's are generally only highly accurate to 50 meters, although can reach up to 300 meters in skilled hands, nowhere near a mile.

Like I said 1 maybe 2 zombies before it hits the ground and is useless and besides that they would be highly inaccurate and would only work if they severd the head completely, which would be very unlikely, it's not like they can float and spin in mid air.

The technology of the rocket propelled chainsaw will be different. we have better technology than when the RPG was made.
I believe this picture of one actually in use in real life more than proves the distance. Just look at how long the smoke trail is.



By the way, RPGs don't have that much fuel on them. Plus if you add some sort of remote control to the rocket it will travel nicely. And you can also make the rocket and launcher bigger thus allowing it to travel further, and accurately in the hands of an expert.
If we also add a C4 charge to it we can have it explode by a detonator button on the remote controller thus taking out all the zombies within the blast radius too.

You don't have to sever a zombie's head to kill it. Damaging the brain kills a zombie. Technically you could kill a zombie with a slingshot if you were good enough.

This is true, you only need to pierce the brain and cause a disruption in the signals getting sent through the brains. Actually instead of explosive charges you could just use a small electrical charge like even that of a AAA battery to disrupt these signals, so if you electrify the tips and have the battery activate by the momentum of the arrow shot it can be very effective this way if you hit the spinal cord you could send a charge up the spine directly into the brain, frying it.