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Muzzle Blast Fuze-Used on Beehive Round.

Sprockets

Well-Known Member
Fuze-M563-Used with M546, APERS

This unusual fuze, used to fire the Beehive Shell with its payload of Flechettes, was a mechanical Time device, which could be set at "MA". I have only seen a small sectional view of its working, which does not show the MA feature. The MA feature used the locking action of 4 Setback Pins in one version, and Alpha Weights in another. What are the later? No patents that I can find. One patent for a Muzzle Blast Fuze, but this did not provide Time, and was a much simpler device. No mention of Alpha Weights anywhere-could they be another name for "Heavy Metal" weights? Has anyone, please, full details of the mechanism, rather than the single drawing to be found?

Thanks,
Martin.
 
You didn't mention your source. Cross section drawing and full description of operation in TM 43-0001-28. And it wasn't a muzzle blast fuze.
 
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Thanks to you both." Muzzle Action" is synonymous with "Muzzle Blast"-the U S Army in 1972 patented a muzzle action fuze under a M B title! TM 43-0001-28 was indeed the reference to which I was referring, and where it mentions earlier experimental forms. THe term "Alpha Weight" has me baffled-no definition anywhere, but I am sure a "BOCNITE" will know!
 
Thinking about why fuze M563 was so different from other mechanical time fuzes, which normally have a back-up safety system to prevent a barrel burst-"Bore Safety", it would seem that normally this safety system does not release until many tens of feet away. The use of four set-back pins, which must lead to a need for very tight tolerances to ensure a sharing of load on each, perhaps is to reduce the inertia of the pins, and lead to a burst closer to the muzzle. As the acceleration ceases on muzzle exit, using lightweight pins would enable their springs to rapidly retract them. The mysterious "Alpha weight"-Is it a weight controlled by acceleration -"a"-hence name, which might have been tried because of no sliding friction, but rotation about an axis, leading to more rapid retraction. Anybody able to assist ?
 
"Alpha Weights"-Nowhere is there a definition of these to be found, but I now think that it refers to detent pins which are of a diabola shape-Two cones joined at the points. These were arranged radially, but would jam im the bores under acceleration forces, due to their shape. The Greek letter "alpha" would resemble the profile od such a pin! Agree?
 
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