Author Topic: SS Valve Retrofit in the Hayabusa  (Read 1165 times)


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Re: SS Valve Retrofit in the Hayabusa
« Reply #15 on: December 21, 2018, 12:57:05 PM »
I mounted the .410 shotgun upper on the Hayabusa today to see what it does with the new SS Valve.... Here is the test load, three 36 cal roundball that weighs a total of 204 gr.... The wad is intended for 1/2 oz. of lead shot (219 gr.), so it should give a pretty good indication of the velocity.... The case is a shortened 2.5" all brass case with the primer pocket drilled out to 3/8", the same size as all the other ports....

The Chrony is a bit reluctant to measure the velocity, throwing low velocity errors (eg. 550 fps) if the wad cup separates early, but discarding the obviously wrong readings I got a three shot average of 850 fps (846, 849, 856)…. That is actually a bit better than I got before, so I'm very pleased.... It works out to 327 FPE, just about what I expected, based on the ratio of bore volumes of the .410 shotgun and .457 rifle....

« Last Edit: December 21, 2018, 12:59:45 PM by rsterne »
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Re: SS Valve Retrofit in the Hayabusa
« Reply #16 on: December 21, 2018, 01:13:28 PM »
This whole project has made interesting reading to say the least. It is always nice when a plan comes together so nicely.
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