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47 m/m Hotchkiss cutaway
- Thread starter Bockscar
- Start date
Bockscar
Well-Known Member
Hi weasel,
Thanks for that, Believe me no one was more suprised than myself when I came across the thread inside! I had a feeling that something was there like a plug maybe, but a threaded one was a real suprise. This project didnt do the milling cutter any good at all - soft at the base getting progressively harder (really harder!) towards the tip.
I just done this bigger caliber for a bit of fun really, and the fact that I had a few of these projectiles helped!...most of the items I section are all small arms stuff.
Thanks for that, Believe me no one was more suprised than myself when I came across the thread inside! I had a feeling that something was there like a plug maybe, but a threaded one was a real suprise. This project didnt do the milling cutter any good at all - soft at the base getting progressively harder (really harder!) towards the tip.
I just done this bigger caliber for a bit of fun really, and the fact that I had a few of these projectiles helped!...most of the items I section are all small arms stuff.
They get harder as you go forward
because they are "Chilled" that is where the forward portion is rapidly cooled and becomes harder when cast or with heat treating later. The metal can become brittle. You might notice a chipped point on some of these projectiles because of this. On a softer projectile the point would just flatten. If cast the upper part of the mold will be sand and the lower an iron cup that can be cooled more rapidly. Chilled shot is mentioned often in the 1885 Hotchkiss book. Solid shot was seldom used or sold by Hotchkiss. The design of your projectile is the same as the kind with an internal fuse, the base screws in, this time the base has a threaded hole for an external fuse.
because they are "Chilled" that is where the forward portion is rapidly cooled and becomes harder when cast or with heat treating later. The metal can become brittle. You might notice a chipped point on some of these projectiles because of this. On a softer projectile the point would just flatten. If cast the upper part of the mold will be sand and the lower an iron cup that can be cooled more rapidly. Chilled shot is mentioned often in the 1885 Hotchkiss book. Solid shot was seldom used or sold by Hotchkiss. The design of your projectile is the same as the kind with an internal fuse, the base screws in, this time the base has a threaded hole for an external fuse.
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Bockscar
Well-Known Member
Good info write up! I was actually going to describe the use of water cooled moulds in the manufacturing process as in the early Palliser designs in my last post. This method as you rightly state would give exactly the sort of conditions that I came across upon sectioning.
I have the Hotchkiss
patent for the base plug, on a disc at home, if I can find it I'll post it. 1882, before then I think everything was PD.
The point of it is that the base or Butt Seal as he calls it is cupped internally so that the force of the expanding gasses hold the side of the cupped part of the base against the side of the projectile body and the whole thing breaks up evenly and the base just doesn't blow out. You can see the cup shape on internally your base. With an entirely cast body this is not needed. A separate base allowed making of the body by other means and the inside could be bored out of better material etc. These pointed penetrating projectiles aren't meant to blow up anything. They are supposed to penetrate the sides of thinly armored craft then explode doing damage with the hi velocity fragments. The solid shot would penetrate everything but only cause one hole versus many so was thought less effective. I found the patent image but not the text.
patent for the base plug, on a disc at home, if I can find it I'll post it. 1882, before then I think everything was PD.
The point of it is that the base or Butt Seal as he calls it is cupped internally so that the force of the expanding gasses hold the side of the cupped part of the base against the side of the projectile body and the whole thing breaks up evenly and the base just doesn't blow out. You can see the cup shape on internally your base. With an entirely cast body this is not needed. A separate base allowed making of the body by other means and the inside could be bored out of better material etc. These pointed penetrating projectiles aren't meant to blow up anything. They are supposed to penetrate the sides of thinly armored craft then explode doing damage with the hi velocity fragments. The solid shot would penetrate everything but only cause one hole versus many so was thought less effective. I found the patent image but not the text.
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