(I know It says rifles but I wanna make a point and this is assualt rifles.)I think there will be Assualt rifles. Im pretty sure about it. If you watch naughtydog's The Last Of Us presentation, right after Joel takes care of the infected, you can see Ellie carrying a gun which I believe is a AK, which then Joel takes from her. Knowing that from the presentation I think there will be Assualt rifles.
Heres the link to the presentation if you wanna check it out: (You see Ellie carrying it at just about 3:20)
Yeah, sure looked like an AK. Still though, they said not to look too much into that particular clip as it was Troy Baker's audition - for all we know this could have just been thrown together with whatever toys they had left from the Ucharted mocap sessions.