That being said..
I would take a pistol, 9mm,.40 or ,.45, whichever I have handy. I carried a pistol on my hip for months in the desert. You get used to it fast. Px4 series are decent. Or a Sig.
A decent carbine, AR-style if I had to, 6.8mm. Nothing fancy, without 10 pounds of extra crap hanging on the picatinny rails (how useful will that flashlight or laser be without batteries?) Reflex site, or an Acog if I can get it. Either that or a Cx4, same caliber as the pistol. I will not pretend I am good enough for a long range duel.
A shotgun. 12gauge, (18in barrel to keep weight down).
But I would also have a decent knife or two a sling-shot (as long as you find decent rocks, there is always ammo) and some fishing line.
I would trap and kill as little as possible with the firearms. Ammo will be hard to get.