Even with those changes to shot blast the flak is still slowing everything to a crawl. Here's my sub munition solution. Maybe you could take a look and see what I need to do to make them dumbfire.
WEAPON
missile: {
name: "flakturret"
group: "FLAK"
target_type: 0x000f00ff
value: 2
ammo: 1000
recharge_rate: 10
refire_delay: 25
salvo_delay: 2
charge: 1
min_charge: 1
damage: 100
lethal_radius: 200
speed: 5e3
life: 10
self_aiming: true
aim_az_max: 1
aim_el_max: 1
min_range: 1e3
max_range: 15e3
max_track: 25e3
carry_mass: 0.54
carry_resist: 2
guided: 1
mass: 0.5
thrust: 3.3e3
drag: 2
roll_drag: 4
pitch_drag: 4
yaw_drag: 4
roll_rate: 1
pitch_rate: 4
yaw_rate: 4
det_range: 5e2
det_count: 10
det_child: "Flakshot SUB"
det_spread: 100
graphic_type: 3, // blob
width: 3,
length: 20,
light: 20,
light_color: (255,255,0),
bitmap: "WeaponEffects/Shot4+.pcx",
flash: "WeaponEffects/Flash4+.pcx",
flash_scale: 3,
sound: "WeaponEffects/EXPLODE1.WAV",
sound_min_dist: 0,
sound_max_dist: 6e3
}
WEAPON
primary: {
name: "Flakshot SUB"
target_type: 0x000fffff,
value: 3,
lethal_radius: 1e3
charge: 1,
damage: 30,
speed: 3e2,
life: 1,
graphic_type: 2, // sprite
animation: "WeaponEffects/Exp20_0004.pcx",
animation: "WeaponEffects/Exp20_0006.pcx",
animation: "WeaponEffects/Exp20_0008.pcx",
animation: "WeaponEffects/Exp20_0010.pcx",
animation: "WeaponEffects/Exp20_0012.pcx",
animation: "WeaponEffects/Exp20_0014.pcx",
animation: "WeaponEffects/Exp20_0016.pcx",
animation: "WeaponEffects/Exp20_0018.pcx",
animation: "WeaponEffects/Exp20_0020.pcx",
animation: "WeaponEffects/Exp20_0022.pcx",
animation: "WeaponEffects/Exp20_0024.pcx",
animation: "WeaponEffects/Exp20_0026.pcx",
animation: "WeaponEffects/Exp20_0028.pcx",
animation: "WeaponEffects/Exp20_0030.pcx",
animation: "WeaponEffects/Exp20_0032.pcx",
animation: "WeaponEffects/Exp20_0034.pcx",
sound: "WeaponEffects/EXPLODE1.wav",
sound_min_dist: 2e3,
sound_max_dist: 20e3,
}