Question: Name the muzzel device with barrel twist of 1:10
SQL: SELECT "Muzzle device" FROM "2-12834315-3" WHERE "Barrel twist" = '1:10';

Question: Name the bayonet lug with AR-15 Lightweight
SQL: SELECT "Bayonet Lug" FROM "2-12834315-3" WHERE "Name" = 'AR-15 Lightweight';

Question: Name the hand guards for AR-15A2 Government Carbine and barrel twist of 1:9
SQL: SELECT "Hand guards" FROM "2-12834315-3" WHERE "Name" = 'AR-15A2 Government Carbine' AND "Barrel twist" = '1:9';

Question: Name the barrel length for barrel twist of 1:7
SQL: SELECT "Barrel length" FROM "2-12834315-3" WHERE "Barrel twist" = '1:7';