Table: ar_15_variants_2
Columns: colt_model_no
stock
fire_control
rear_sight
forward_assist
barrel_length
barrel_profile
barrel_twist
hand_guards
bayonet_lug
muzzle_device

Question: Can you tell me the Barrel twist that has the Barrel lenght of 11.5 in.?
SQL: SELECT "barrel_twist" FROM ar_15_variants_2 WHERE "barrel_length" = '11.5 in.'