Grazing bullets

[stugumby]

You can see sparks whenever you hit the armor plated areas of an IL-2. if this is what your talking about by grazing, the bullet not being armor piercing is basically disintegrating and metal on metal makes a spark or flash effect.

[Pursuivant]

I think that IL2 handles bullets vs. armor as a simple force vs. resistance calculation.

If the bullet doesn't have enough force to penetrate armor plate it "vanishes" and does no further damage. The armor is undamaged and is "immortal" until the plane itself is destroyed.

If the bullet has enough force to penetrate armor, it continues on its original trajectory, but with reduced force. No bullet deformation, deflection, shrapnel from the armor penetration, etc. Generally, this makes sense for relatively small-caliber AP rounds. Maybe less sense for 20mm+ rounds and non-AP bullets.

[dimlee]

I think that "grazing" theory makes sense. Sometimes I see the same effect on the a/c I fly. It doesn't happen too often (unfortunately!).

And it probably depends on the damage model of particular aircraft.
I experienced the "grazing" on Bf 110 and probably on Hs 129. I'm sure about Bf 110 as I flew it often with recording on and then studied some tracks. Never on Ki-45 or Pe-3bis - once you feel a hit, that means something bad happened even if you see no damage on the plane's skin.

Recently I tried Beau Mk.21 vs Pe-8 on Samara server. 85.113.41.253:21002. There are maps with interesting airplane sets. When I keep at respectful distance from Pe-8 formation, I can get several hits, can feel them - but nothing happens.