Across:
   1. Fellow bowler perhaps beat one, as noticed in drinks break? (9)
   6. Bad moods caused by major blows? (5)
   9. As their knockout, bomb odd bits throughout island (7)
  10. Language before English is relevant (7)
  11. Wrongly set, a short circuit may involve these (9)
  12. Such vowel dropped by custom (almost)? (5)
  13. Ends game so horrifically (6)
  15. Sending up whisky in glass bottles (6)
  19. Traditional ruler with no time for modern weapon (6)
  20. Fatwa partially overturned with new horror heaped on 5 down (3 3)
  23. Name of the island that liked enormous heads? (5)
  25. Motorcar enthusiast's piece of equipment is a nasty sort of 1 down (9)
  27. Caustic complaint about road by head of traffic (7)
  28. Cryptic grid has something that might help in the scullery (7)
  29. Obscure: 150 over 2 (5)
  30. Fate planned for 6 down and Tokyo: belt till reduced to turning to west (6 3)
Down:
   1. American parent takes hours moving nasty sort of 29 (8)
   2. So silences are, roughly? Not roughly! (9)
   3. Lengthy periods suffering as one (5)
   4. President without present leadership (an ex-president) (6)
   5. When a gas, a killer, shrouds city (8)
   6. City near 9 across shire lost, the time man bared all (9)
   7. Fancy feature seen when 21 down weapon used (5)
   8. Points out ridiculous ease - "it's child's play!" (6)
  14. Scared to embrace love and test heart, as previously mentioned (9)
  16. From the south... tavern has bread roll, cup of coffee and some seafood for Louisiana dish (5 4)
  17. Fate of the Kursk - some reckoning! (8)
  18. Mother of pilot flying solo getting up and finally having a say (5 3)
  21. A tennis player that can't be broken down? (6)
  22. Two bit parts perhaps for gangster (6)
  24. Roots out core part (5)
  26. Sulfur is placed on aluminium fibre (5)