I noticed that some weapons have a passive effect when you Pack-a-Punch them. For instance, the Gallo shotgun has an explosive ammo effect which sometimes triggers on melee.
What are all the weapons that gain an effect besides increased ammo / damage when Pack-a-Punched (and what is that effect?)
I could not find a list on the wiki, and a lot of results returned are for earlier COD titles (at least at this point). There were weapons in other Black Ops titles that changed drastically when you PaP'ed them, most notably the ballistic knife and the crossbow, so I was curious if there was anything along those lines.