Welcome to the wonderful world of the ever-fickle Hakkotsu Thunder B!


While BTA members are not affiliated with Hakkotsu, nor are we experts with their product the Thunder B CO2 Sound Effect Airsoft Simulation Grenade. We do however own and regularly use quite a few of them!


The following is a compilation of many Airsofters experience with the Hakkotsu Thunder B…



  • There are some minor changes in the version two cores. A longer/sharper striker. Different material washers, longer pins, a groove in the plastic centering collar, and a hole in the bottom cap. No one has come forward with any information about these changes and if they improve the performance. (Ver. 1 core pictured below.)

  • The pineapple shells are consistently louder than the “Sound Device” shells.

  • Unexploded shells can be used again. However, be prepared to throw them immediately and leave them be a while, they can go off faster or slower than normal.


  • Purchase extra pins, they are easily lost.


  • Get a retractable I.D. Badge holder. You can attach it to your vest and clip it to your pins so you do not have to keep track of them in game. GENERAL ARMY/NAVY OUTDOOR (http://www.generalarmynavy.com/)4974 South Redwood Rd.  Salt Lake City, UT 84123 (800)433-9185 has one with double cables instead of string, located near the registers. 

  • Use Daisy brand 12 gram Co2 powerlets (easily found at Big5). It has been found by many users that the Crosman brand do not puncture well, sometimes taking two or more strikes to break the seal.

  • A BTA member zip-tied a chem. light to a Thunder B and threw it in a night game. I worked great! Everyone knew where it was and when it went off, and then they knew what it was! It took out seven enemy players… in the dark! Afterwards it was easily found and retrieved. Later I discovered these…


NITE IZE SpotLit (http://www.niteize.com/collections/led/products/spotlit)

(I specifically recommend the SpotLit because it has a metal clip, not plastic.)

            They are easier to activate before throwing and easily retrieved. Just make sure you get white,

            so as not to be confused with already used BTA game colors (No red, blue, green, yellow, or pink).


  • If you spoon breaks off, and it most likely will. The grenade can still be set and armed. You just cannot hold it after pulling the pin; it must be thrown right away.

  • The gen 2 shells utilize color-coded screw on end caps for three and five minute “fuses”, and due to the caps the shell is forced to break on the sides for maximum loudness. However, just as they became available it was discovered the new end caps break far too easily.

  • The dumbbell shaped “Flash Bang” shells were just released. They seem to be consistently loud like the pineapples.

  • FOG from Airsoft Pieces (http://www.airsoftpieces.com) and JFFA - Just For Fun Airsoft has a custom modification for the core that gives you a reliable five second “fuse”.


  • Here are the complete English instructions (many times the kit will come with incomplete “chinglish” instructions).


Like with most airsoft gear after a bit of practice Thunder Bs can add to the game and be great fun! Even the occasional “duds” still create entertaining “war-stories”!




Here is a link to a few more tips I have used and found useful!




Furthermore, there will soon be a new version released, the spoon-less “trip-wire” Thunder-B!


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