GameRules example for counting FP explosive kills

class VozGameRules extends GameRules

function bool PreventDeath(Pawn Killed, Controller Killer, class<DamageType> damageType, vector HitLocation)
{
    local class<KFWeaponDamageType> KFDamType;
    local SRStatsBase stats;

    if ( (NextGameRules != None) && NextGameRules.PreventDeath(Killed,Killer, damageType,HitLocation) )
        return true;

    KFDamType = class<KFWeaponDamageType>(damageType);
    if ( PlayerController(Killer) != none ) {
        stats = SRStatsBase(PlayerController(Killer).SteamStatsAndAchievements);
    }

    if ( Killed.IsA('ZombieFleshpound') && KFDamType != none && KFDamType.default.bIsExplosive ) {
        // Fleshpound killed by explosive damage
        if ( stats != none ) {
            stats.Rep.ProgressCustomValue(Class'VozFPKillProgress ', 1);
        }
    }
    return false;
}