The peasant railgun and the squirrel chain are effective in 2 conditions:

1. Each one with above average strength contributes a +1 "helper" bonus. You're not concerned with how fast it gets to a place, but that with everyone helping, you can get it around the world and back again - and everyone helped.

2. You're not concerned with the damage - only how it gets there. So if you can get a Hands Across America thing happening, you can pass messages in a single round.