Actually the best way to get them is via, taking a big cap out to unknown and knocking out Nomad BSs and caps...also take out fighters you might get some cannons (which are better)
(If you find any mistake in my English, please let me know via a PM)
(Really, I speak terrible English, so please, tell me if I make mistakes. I'd like to improve it a bit )
What are you talkin about Commodore??? Blasters and Cannons are almost equal...and Cannons are more energy efficient...and Nomad weapons are now weaker than Codenames but stronger than class 9s....
The best way to get nomad guns is to find nomad battleship groups, and pick off the fighters as they sit in formation with the larger ships. I find it quite easy to kill them this way.