To get the name of any weapon (in the future), make the player the class of unit that has the weapon (in this case the resistance sniper/Silenced Black Op etc.) and use a trigger like this:
TriggerRadius: 0,0
Condition: Radio Alpha
Condition Field: this
OnActivation Field: hint format ["%1",weapons player]
So when you hit radio alpha, a hint will pop up with a list of the editor names for all the player's weapons. Using this method, I found the weapon names you were after. Then, assuming you just put 'mag' on the end (which in this case you do, I tested it) gave me the magazine names. So, they are as follows:
"HuntingRifle" -- "HuntingRifleMag"
"Ingram" --- "IngramMag"
"GlockS" ---- "GlockSMag"
"Revolver" ----- "RevolverMag"
Happy editing