Also, I really wish Destiny had put Snipers in the heavy category, instead of Special. I think it would have made more sense since you wouldn't spawn with Snipe ammo and would have to go back to the dangerous center of the map to get more. Also, have always considered Sniper Rifles as being in the "heavy" category anyway.
I think the philosophy was
Primary - 1, maybe 2 kills a clip. Used best when combined with grenades/melee.
Special - 1HKO weapons that are designed to work at specific ranges. Shotgun=Close, Fusion=Medium, Sniper=Range. Sidearms are weird and obviously don't fit the theme.
Heavy - A weapon designed to get you multikills, and thus needs to be scaled back in availability.
I see Snipers and Shotguns as two sides of the same coin. Them being default weaponry isn't what's bad, it's the availability of special ammo.
Plus, Halo usually gave 1 sniper to both teams in maps it was in play. It was rarely, if ever, at the center of the map like Rockets/Laser/Banshee was.
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Also, Kor's recommendation for Special Ammo:
I've been doing this for a couple months now, but I've never seen anyone really go into detail with it.
I highly recommend you make an effort to steal the enemy ammo crates during PvP games. As a player that relies heavily on my special weapon, I very much notice when I don't have my ammo, and feel impaired until I get some. Thus, I imagine players like me feel the same.
So I started making runs for ammo crates to the best of my abilities.
Chances are the team that controls the crates, controls the map. Each map has either 3 or 4 crates (Not including the 3 crazy large ones). Thus, you want to make sure you're triggering the majority each time.
I'm sure some people could argue, but I totally believe it is worth a death, to steal a special ammo crate from the enemy team. This seems to be more important at the beginning of the match during the first wave of special, usually momentum will carry your team to the win after this point, but sometimes not.
The best practice is to just always open a crate that can be opened, there is no reason to save it for later.