So after using the Dalek Mod guns I have had several suggestions.
An M16 has 3 types of fire that you can switch through with the press of a button: Semi Automatic, Fully Automatic, and 3 round burst
Another idea is that you can Aim down sights for fighting enemies at a long range.
The Ak47 can also be switched between semi auto and fully automatic
same sights and recoil climb when shooting at full auto.
Full auto and Semi auto
Lots of damage at close range with steady damage drop off
Fire 10 shots at a time so that its not as overpowered
Daleks and their Guns
Daleks rate of fire is much slower and they warn you with an Exterminate when they are about to shoot and they also have a slower turn rate as in the show they have a slow turn. But they will do a one shot kill and that will apply to the gunstick and you get the skeleton death animation but they still shoot very slowly and yell exterminate when about to shoot. Another thing that i think could be cool is that if you take a dalek down to half health and then use your sonic screwdriver on them then the dalek shell will open up and you kill the mutant inside you can then enter the dalek suit and ride around in it use the dalek gun and daleks will not attack you but iron golems and other mobs that hate daleks will then attack you.
I would recommend the ability to craft attachments that can give your weapons buffs but i dont feel that they are necessarily needed at this time