We actually carried 38 Specials. S&W Model 15 Combat Masterpieces.
They were to be used to protect the Sealed Authenticators in case of an attempted break in.
As for turning keys, there were four other Launch Control Centers connected together in the Squadron and the 50 missiles only need to see two of those capsules turn keys to launch.
Other than the psycological tests beforehand, were there any controls in place that would prevent two guys getting together and turning their keys? If you can’t disclose that - that’s fine.
An old boss of mine was part of a group that would look at airphotos of the USSR and change the targets of the missles at various intervals back in the early 60’s.
In the 80’s I was at a science convention with him and for lunch we were seated with a bunch of Russians. He asked one guy where he was from.
“Oh yeah - ABC town! Back in the day I would help in picking targets for our nukes. You guys had that big engine factory there - that was on our list.”
Then he did the same with all the others! I found it really funny - he was just treating it as matter of fact. And his memory with all of the details of the locations of things.