Tell the others about the guns

You look at Ryan, a question burning in your brain, "If you're so worried about how little you can trust anybody here, what makes Will and I any different?"

"Honestly, man, nothing. If I had had it my way, I'd have found the guns while the two of you were searching a different part of the ship and stashed them away without a word. But that's not exactly how things played out now, was it? And I'd rather share the guns with two people instead of eight."

That was the answer you were looking for. Ryan clearly has no qualms about selling you or your best friend down the river if he has to. Will must have reached the same conclusion too, because before you can open your mouth to speak he is already answering.

"Uh-uh. No dice. You just said that you would rather have all the guns to yourself. For all we know, you'd sneak into our tents while we were away and steal the rest of the firepower for yourself. I don't know the others all that well, but I know that as of right now, I trust you less than anybody else on this godforsaken planet."

Ryan scowls at the two of you, but knows he's beaten. You say a silent prayer of thanks that he hadn't had a chance to load the pistol he's carrying. The three of you head out of the ship around midday to tell the others about your findings. Alyssa is apparently still acting as group leader, much to the chagrin of Alex.

"That's great, you guys! After you've had a chance to eat and rest a bit, take the guns and hike around for the rest of the afternoon and let us know what you find!"

Alex, to his credit, is quick on the draw, and butts in to expose the weakness you've already seen in Alyssa's plan.

"No! They can't! We still need something here for our own protection! If there are any dangerous animals around, they were probably too scared by yesterday's crash to bother us. Today, they might be curious! We need to keep some guns here for us!" Alex sits back, clearly pleased with himself for getting one up on Alyssa. She, however, is quick to recover. "Alright, Alex, fair point. Ben, you were the first to volunteer, so I'm making you group leader. You can decide which guns to take, and who to leave the guns with. What'll it be?"

Alyssa has put you in a difficult situation, and everyone around you knows it. You can accept the group leader position, but that will serve as acknowledgement that Alyssa is in charge. She's done a good job so far, but you aren't sure you know here well enough to be comfortable under her command. Not to mention, siding with her will royally piss off Alex, though you imagine it wouldn't be the worst thing to immediately be on the leader's good side.

On the other hand, siding with Alex will help reset the status quo and undo a lot of the progress Alyssa has made toward establishing herself as leader, allowing you to get to know your companions a little better before deciding who to support as the de facto leader of your group. You'll also earn a lot of points with Alex, though at the expense of Alyssa's trust.

And, of course, you have Ryan to worry about. Siding with Alyssa will make sure you keep most of the firepower with you and Will. If you side with Alex, you'll be running the risk that Ryan may try something stupid with the guns.