Huh so did some Mathhammer on Serpent heavy weapon choices, which had some interesting results from what I thought. Remember these don't take into account range, terrain, cover, positioning of threats etc.
Key:
FSA - Armor value of what your shooting at
SC - Shuriken Cannon,
EML - Missle launcher Krak,
SL - Scatter laser, Star - Star Cannon,
BL - Bright Lance, SCU - Shuriken Cannon underslung
Hit % - Chance to hit based on
BS and
TL or not
rng - Range
Combat - Number of shots that hit at combat speed based on hit % and shots (partial values kept for cleaner overall statistics)
Cruise - Number of shots that hit at cruising speed based on hit % and shots (partial values kept for cleaner overall statistics, SCU gets 0 as only one weapon can fire at cruising)
Glance % - Chance to glance based on weapon
Str/rules vs FSA
Pen % - Chance to Penetrate based on weapon
Str/rules vs FSA
G Death - Chance to immobilize on glance chart
Pen Death - Chance to immobilize or better on pen chart
Kill Glan - Overall chance to immobilize on glance chart based on Glance % and G Death
Kill Pen - Overall chance to immobilize or better on pen chart based on pen % and Pen Death
Tot Kill - Overall chance to immobilize or better
Combat/Cruise D - Overall chance to immobilize or better base to Tot kill and the number of shots at Combat/Cruising speed
%
PP Combat/Cruise - The percentage point of immobilize or better per point of weapon cost.
As you can see from the OCD chart Shuiken Cannons are actually the best per point for immobilize+ AV10-12 vehicles. At AV12
EML are your best bet for popping them open, and 13-14 your money is best on Bright Lances. If you KNOW your going to be facing a pile of
AV 10-11 vehicles Dual S Cannons will be your best bet.
Remember though this is a PURE statics setup, and the range at which you will have to strike and the Serpent's roll will take a huge factory on what setup your looking for. This also doesn't take into account what the weapon choices can do against non-vehicle. NOTE: As with all mathhammer, the dice can and will hate you.