Hi, I have just tested the Brimstone in my SF2:E install (latest patch applied) and worked 12 out 12 on the Tornado GR1A.
Fired at distances from 8 km down to just under 2 km, at angles of 0 to about 45 degrees from target, not a single miss.
Here is the weapon data entry, I cannot recall to have modified it at all:
[WeaponData001]
TypeName=BrimStone
FullName=BrimStone
ModelName=BrimStone
Mass=48.500000
Diameter=0.177800
Length=1.800000
SubsonicDragCoeff=0.120000
SupersonicDragCoeff=0.222000
AttachmentType=NATO,UK
SpecificStationCode=
NationName=RAF
StartYear=1999
EndYear=2020
Availability=2
BaseQuantity=24
Exported=TRUE
ExportStartYear=1999
ExportEndYear=2020
ExportAvailability=2
WeaponDataType=1
RailLaunched=TRUE
RocketPod=FALSE
Retarded=FALSE
FinStabilized=TRUE
SpinStabilized=FALSE
HasGrowl=FALSE
EffectClassName=LargeMissileEffects
ReleaseDelay=0.500000
WarheadType=2
Explosives=25.000000
FusingDistance=1.000000
ClusterBomblets=0
ClusterDispersion=0.000000
GuidanceType=8
Accuracy=90
MaxTurnRate=5.000000
MaxLaunchG=3.000000
LockonChance=95
LaunchReliability=95
ArmingTime=0.000000
SeekerFOV=15.000000
SeekerGimbleLimit=35.000000
SeekerTrackRate=15.000000
SeekerRange=16000.000000
CLmax=14.000000
MinFreq=0.000000
MaxFreq=0.000000
MinLaunchRange=1000.000000
MaxLaunchRange=14000.000000
Duration=90.000000
CounterCountermeasure=0.000000
NoiseRejection=0.000000
CapabilityFlags=0x00000004
LoftAngle=0.000000
DescentAngle=0.000000
MaxLoftAltitude=0.000000
BoosterStart=0.000000
BoosterDuration=4.000000
BoosterAccel=13.700000
BoosterEffectName=MissileFireEffect
BoosterSoundName=Missile
BoosterNodeName=
BoosterPosition=0.000000,-0.816200,-0.000600
SustainerDuration=0.000000
SustainerAccel=0.000000
SustainerEffectName=
SustainerSoundName=
SustainerPosition=0.000000,-0.816200,-0.000600
InFlightEffectName=MissileInFlightEffect
InFlightSoundName=
ReleaseAnimationID=-1
EODisplayFlags=0
CEP=0.000000