World of Tanks – Understanding Reload Time in World of Tanks

The formula for calculating the effective armor rating in world of tanks is:

Armor tickness/cos(impact angle)

With an Angle of > 70% always leading to a ricochet, this leads to this table:

Impact Angle    Effective Armour Thickness
    0°                 100%
   10°                 101.54%
   20°                 106.42%
   30°                 115.47%
   40°                 130.54%
   50°                 155.57%
   60°                 200%
   70°                 292.38%
  > 70°                Ricochet

(source: world of tanks effective armor rating)

Which angle to chose depends a lot on the tank you're driving and how it is armored. But in general, having at least a slight angel towards your opponent is a good idea.

For example, if you're driving a tank with 100mm front armor and 80mm side armor, a 45% angle on both front armor would give you an effective front armor of 141mm and effective side armor of 113mm. In this example having the opponent hit your side at an angle would still give a lower chance of penetration than hitting the front armor at a straight angle.

However if the situation is the same, but the tank you're driving only has 60mm side armor this means the effective rating of the side armor would be 85mm, which means you're giving your opponent an opportunity at an easier penetration, in this case it would be still good to present yourself at an angle, but less than 45%. (a 30% angle in this case would give you 115mm front armor and 120mm side armor)

Most SPGs have rather small gun arc so you need to plan what you do beforehand. Most SPGs with big gun arcs are the ones which were added in 8.6 patch (the patch that nerfed SPGs to the ground). That means you need to know the maps well, know where you can shoot to which positions and where the enemy is going to be usually. Plan ahead and preaim, dont be hasty in swapping targets around the map and focus on one area at the time. Patience is needed and its quite dull at some points too, unfortunately.

Buying gold ammo for SPGs is not really needed. I have 2 T10 artys (US and French) and I havent really used any premium ammo along the way.