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Rifling a projectile with the projectile, Not the barrel

Posted: Sat Feb 27, 2010 9:02 pm
by Pax
I made a spudgun, i'm shooting AA batterys wrapped in tape, Im wondering if i can cut grooves in the tape to simulate rifling, Or any other way to rifle it through the projectile.



Edit: I dont care how i do it, I just want the battery to spin without some big machinery to rifle it with, If theres a way to rifle a barrel without a lathe (Or whatever its called) preferably with hand tools, I would be greatfull

Posted: Sat Feb 27, 2010 9:19 pm
by Hawkeye
Check out rifled shotgun slugs like the Remington slugger. You would probably be better off making slugs from Hot glue or Epoxy with a lead or ball bearing front and then filing angled grooves in the tail end.

Posted: Sat Feb 27, 2010 9:25 pm
by ramses
Welcome to Spudfiles! There are ways to rifle barrels without expensive tools, but you will need either a grinder or a file to do it to metal pipe.

There are actually two "how to"'s on this site. One for Metal Barrels and one for Plastic.

A search in the how to section for the word "rifle" turned both results up, but since you are new here, It's probably okay...

I would recommend the version for metal pipe for plastic as well, because it is more controlled as far as the rifling rate goes. You can use this caluclator to determine the proper angle to grind. keep in mind that this will be around 1/20 TPI, so you would enter .05 into the TPI box.


Additionally, make sure your barrel is pressure rated, and don't make the grooves too deep. SCH80 pipe would be ideal.

Posted: Sun Feb 28, 2010 9:42 am
by jrrdw
You can also start your tape wrapping at a angle leaving a twisted portion of the battery uncovered from one end to the other. No tools needed for this method, well something to cut the tape with.

Posted: Sun Feb 28, 2010 2:57 pm
by ramses
jrrdw wrote:You can also start your tape wrapping at a angle leaving a twisted portion of the battery uncovered from one end to the other. No tools needed for this method, well something to cut the tape with.
I have to say that I doubt that that would be effective, because of the steep angle required. for 1:20, 2" ID, it is IIRC, a 15* angle from the axis. I dont' think tape would really provide the grip that is needed.

Posted: Sun Feb 28, 2010 6:41 pm
by kozak6
It's not really the rifling on a projectile that stabilizes it. It's just left over from the rifling imparting a spin on it.

With rifled shotgun slugs, the rifling allows the projectile to safely swage down if fired through a choke.

Look here:
http://www.spudfiles.com/forums/air-rifling-t16401.html
http://www.spudfiles.com/forums/project ... 19748.html

It's not so much that you need to spin the projectile, it's more that you have to stop it from tumbling.