Author Topic: SS Valve Retrofit in the Hayabusa  (Read 888 times)

rsterne

  • Member 2000+fps Club
  • Global Moderator
  • Hero Member
  • *****
  • Posts: 1732
  • Mozey-On-Inn and see what Coalmont has to offer!
    • Mozey-On-Inn
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....

Bob
« Last Edit: December 21, 2018, 12:59:45 PM by rsterne »
  • Coalmont, BC

Alan

  • Administrator
  • Hero Member
  • *****
  • Posts: 2254
  • Set the example... Don't be one!
    • Mobile Amateur Radio
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.
  • Roswell, New Mexico
Alan

I have an Omega compressor. If you're a fellow Guild member, and you pass through Roswell, NM, I'll fill your portable tank as a courtesy.