A couple of people have been pestering me to try a much heavier bolt.   Something on the order of 10,ooo grains seems to be the consensus.  While I have been heavily swayed by prior experience with  500 or so shots on the old Gallwey  ballista (see second posting for this blog, way back when), that worthy beast with its 5″ diameter springs seemed happiest tossing out a bolt around 5,000 grains.   Using the same ammo,  Firefly with her 3″ springs and inswinger design, has been putting out muzzle energies that are the ballistic twin of the old Gallwey machine (1100 ft/lbs.)    It may well be,  that with the new magnum springs preloaded to the max,  Firefly will actually prefer chunking out  heavier projectiles;   at least to the point her master doesn’t get all prissy about the rainbow trajectory.

A flat shooting bonanza is still the final goal.  However,  there is no reason not to start tomorrow’s tests by firing off a heavy harpoon  or two.   Who knows what useful traits we might discover?   Perhaps something retrograde for the Japanese whaling fleet.

One Response to “Harp-oon.”


  1. Harpoon Joe says:

    Harpoon eh?

    I decided to try a little lighter harpoon for my ballista bow. Im downsizing from 1600 to 1200 for my little 25lbs pull machine! 32 inches long, 5/8 diameter.

    My data here(scroll down) cannot be argued with as its duplicatable upon demand. Ya need to get with the program LOL. I’ve been after you for years to shorten and lighten them log things, beautiful as they are…

    Come to the Darkside Luke…
    http://www.romanarmytalk.com/rat/viewtopic.php?f=20&t=28502&p=258405#p258405

    You would see a marked improvement if you shortend them down to where length was a third of bundle spacing. When you approach 400fps, 5-10% increase makes a big dif. Bigger still at a 4 to one ratio. Then those light 5000 grains will really smoke. You have enough power to send up an Apollo.

    I think Firefox will thank you for it by making yu smile!

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