How to use Rapid Fire Weapons in Warhammer 40k 9th Edition. One of the most common weapons in Warhammer 40k are rapid fire weapons. That's why it's so important for you to understand how they work and the simplest ways to use them. Watch this breakdown and make your opponent think twice before they charge your Astartes Units! If you want to learn more about Warhammer 40k and get exclusive tips and tricks from the pros on how to play, paint, and build up an epic collection download our free guide