Does Gyrocopter's Rocket Barrage go through Stout Shield and armor?

Last game as Axe I had a Stout Shield and a Ring of Protection as starting items. I faced Gyrocopter who gave me quite some trouble with his Rocket Barrage ability, which makes me wonder:

Does block (from the shield) and/or armor (from the ring) help vs Rocket Barrage?

I've searched, and merely came up with the ability description in turn leading me to investigate how Magical damage works, but that gave me nothing definitive. The Stout Shield and Ring of Protection articles gave no direct answer either.

I'd guess from "flavor" that shields and rings are ineffective against magical damage, but then again I would think them to be effective against "rockets". But then again, in Dota 2 mechanics don't always flow logically from flavor.

Anyone got a definitive answer (preferably with some explanation how I could / should have figured this out on my own)?