Correction: the above is against a skill of 11 (BARs are Reliable, but not Accurate).

Five BAR Rangers in the SE house targeting each one of north, east, north-east, west, south-west with bursts of 9 rounds (18 bullets) each:

(3d6)[9] Guns (Rifle) 12 (13 skill, +5 acc, +1 sight, +1 brace, +1 determined, +4 RoF, -11 speed/range, -2 sitting) Rcl 1 for (6d6+1)[17] (6d6+1)[20] (6d6+1)[28] (6d6+1)[23] etc.
(3d6)[11] Guns (Rifle) 12 (13 skill, +5 acc, +1 sight, +1 brace, +1 determined, +4 RoF, -11 speed/range, -2 sitting) Rcl 1 for (6d6+1)[20] (6d6+1)[20] (6d6+1)[22] (6d6+1)[25] etc.
(3d6)[11] Guns (Rifle) 12 (13 skill, +5 acc, +1 sight, +1 brace, +1 determined, +4 RoF, -11 speed/range, -2 sitting) Rcl 1 for (6d6+1)[18] (6d6+1)[24] (6d6+1)[21] (6d6+1)[16] etc.
(3d6)[12] Guns (Rifle) 12 (13 skill, +5 acc, +1 sight, +1 brace, +1 determined, +4 RoF, -11 speed/range, -2 sitting) Rcl 1 for (6d6+1)[21] (6d6+1)[22] (6d6+1)[26] (6d6+1)[27] etc.
(3d6)[5] Guns (Rifle) 12 (13 skill, +5 acc, +1 sight, +1 brace, +1 determined, +4 RoF, -11 speed/range, -2 sitting) Rcl 1 for (6d6+1)[29] (6d6+1)[18] (6d6+1)[22] (6d6+1)[20] etc.

Rangers officer with a BAR in the SE house targeting another south-west with a burst of 9 rounds (18 bullets):

(3d6)[11] Guns (Rifle) 14 (15 skill, +5 acc, +1 sight, +1 brace, +1 determined, +4 RoF, -11 speed/range, -2 sitting) Rcl 1 for (6d6+1)[22] (6d6+1)[17] (6d6+1)[24] (6d6+1)[18] etc.

Two M16s in the SE house targeting one biker to the north with long bursts of 13:

(3d6)[10] Guns (Rifle) 11 (13 skill, +5 acc, +1 sight, +1 brace, +1 determined, +3 RoF, -11 speed/range, -2 sitting) Rcl 2 for (6d6+1)[18] (6d6+1)[20] (6d6+1)[25] (6d6+1)[19] etc.
(3d6)[6] Guns (Rifle) 11 (13 skill, +5 acc, +1 sight, +1 brace, +1 determined, +3 RoF, -11 speed/range, -2 sitting) Rcl 2 for (6d6+1)[27] (6d6+1)[19] (6d6+1)[23] (6d6+1)[27] etc.

Two M16s in the SE house targeting one biker to the east with long bursts of 13:

(3d6)[7] Guns (Rifle) 11 (13 skill, +5 acc, +1 sight, +1 brace, +1 determined, +3 RoF, -11 speed/range, -2 sitting) Rcl 2 for (6d6+1)[16] (6d6+1)[26] (6d6+1)[19] (6d6+1)[22] etc.
(3d6)[10] Guns (Rifle) 11 (13 skill, +5 acc, +1 sight, +1 brace, +1 determined, +3 RoF, -11 speed/range, -2 sitting) Rcl 2 for (6d6+1)[26] (6d6+1)[30] (6d6+1)[24] (6d6+1)[25] etc.

Two M16s in the SE house targeting two bikers to the west and south-west, but shooting them with long bursts of 13 only if BAR rangers miss them:

(3d6)[12] Guns (Rifle) 11 (13 skill, +5 acc, +1 sight, +1 brace, +1 determined, +3 RoF, -11 speed/range, -2 sitting) Rcl 2 for (6d6+1)[20] (6d6+1)[22] (6d6+1)[13] (6d6+1)[29] etc.
(3d6)[14] Guns (Rifle) 11 (13 skill, +5 acc, +1 sight, +1 brace, +1 determined, +3 RoF, -11 speed/range, -2 sitting) Rcl 2 for (6d6+1)[26] (6d6+1)[19] (6d6+1)[17] (6d6+1)[24] etc.

All of the stuff above is against the bikers, not bikes, and might leave the bikes intact and/or overpenetrate into passengers.