Do some ships have internal armor around their magazines?

Hi everyone. Yesterday I was fighting a sovetsky Soyuz in Roma. He was broadside on to me and I detonated his magazine 3 times, under each turret, one salvo after another. But he did not sink. The battle ended before I could kill the rest of his crew. Similar events have happened before with ships surviving multiple magazine detonations.

But in Roma, a magazine detonation always one-shots me, even when my crew count is near 100%. I’m spaded with ammo-wetting. Are there some interior armor bulkheads in Soyuz and other ships that is not existent in Littorio class ships? Why is every other ship so survivable?