As a minimum, the Command Duty Officer, the Gunner's Mate of the Day, and the Roving Patrol. Others who generally had the keys were the Weapons Officer, the Chief Master at Arms, and the Chief Gunner's Mate.
We were a small ship and there was enough ready stuff in our small arms locker to cause a major incident. There was enough stuff in the Small Arms Magazine to invade a Banana Republic in the 1920s. I know because we had to off load it before having some hot work done in the area. With what was in there I'm glad we did.
WWG1WGA
Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)