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New idea for fin-stabilazed ammo?

Posted: Sat Aug 11, 2018 6:08 pm
by Alex345
I have just ordered a piece of aluminum profile tubing that has a shape for which i've been looking for a while:
Xporfile.1.jpg
Xporfile.1.jpg (18.7 KiB) Viewed 4863 times
I was thinking of cutting like 2cm long pieces of this piece and attach those to a piece of wire rod to serve as 8 mini fins. Wonder if this would be accurate? If the projectiles can be easily made consistently.
round.2.png
round.2.png (25.21 KiB) Viewed 4863 times

Re: New idea for fin-stabilazed ammo?

Posted: Sun Aug 12, 2018 6:12 am
by jackssmirkingrevenge
Very interesting find!

With regards to your projectile design, I'm not sure it would work as-is, you probably need the tail portion to be longer - basically the sharp angle at the rear of the front mass will probably not allow enough air to flow over the fins for them to be effective.

Have a look at the M830 120mm tank round for example:

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That taper on the end is going to smooth the airflow and enable the fins to stabilize the projectile.

Russian 125mm shells with a similar blunt profile also feature spring-out fins that extend past the caliber diameter to be effective:

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Re: New idea for fin-stabilazed ammo?

Posted: Sun Aug 12, 2018 5:29 pm
by Alex345
Thanks for the input! I'll keep a design in mind with a longer tail section and where the body of the round tapers down to the piece if wire rod that holds the fins in place :)

These also look good for making some folding fins too!

Re: New idea for fin-stabilazed ammo?

Posted: Sun Aug 12, 2018 6:44 pm
by jackssmirkingrevenge
Can you link to where you found it?

I think something like this would also work very well:

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Re: New idea for fin-stabilazed ammo?

Posted: Wed Aug 29, 2018 11:22 am
by Alex345
Sweet! What is that? Reminds me of a heatsink but i'm lost as to why it has a hole in the middle tho... It came from an event company in The Netherlands, so shipping was doable.

https://www.fritz-events.nl/adam-hall-a ... l-7mm.html

Just got back from vacation so i'm gonna clean up my workspace a bit and try and wrap my mind around this projectile i'm building, as i'll be trying thin cut pieces as fins for small cal projectiles, but i'm also working on one with deploying fins for a bigger cannon.

Re: New idea for fin-stabilazed ammo?

Posted: Sat Sep 01, 2018 7:59 pm
by Alex345
Some messing around...
40654326_320354475382707_4268847156036632576_n.jpeg

Re: New idea for fin-stabilazed ammo?

Posted: Wed Sep 19, 2018 8:16 am
by jackssmirkingrevenge
Looking good!
Reminds me of a heatsink but i'm lost as to why it has a hole in the middle tho
Yes it's a heatsink, amazing how many different designs there are if you look around.