Cement molds and making cement slugs

[gwoloshyn]

For my new air cannon, which I will post this weekend when I finish it, is going to shoot these cement slugs I made. Pretty straight forward, cut pvc lengths diameter of your barrel and fill with quikrete cement.

What would be the best way to make the slugs have a semi-pointed tip like a nosecone of some sort after they dry? this would make them fly faster, farther, and straighter it seems like.

[pyrogeek]

what about forming a cone out of aluminum foil in a hole in the ground, stick the pvc over it, and fill?
What about the wear you'll be causing on your barrel? Maybe you should make sort of a liner in the PVC out of plastic wrap before filling with concrete.

[gwoloshyn]

I'm using a separate length of pvc pipe for the molds.

[benstern]

Just make sure the surface of the cement is PERFECTLY smooth or you will seriously screw up your barrel. Smoother than the inside of pvc.

[Novacastrian]

Look at this thread-
http://www.spudfiles.com/forums/pimpin-ammo-t9989.html
Near the end pages are some hot glue rounds.

[Novacastrian]

Cement is a term used to describe a lot of glues benny

[spudgunnerwryyyyy]

Yes but he also mentioned quickcrete which definatley
would screw up your barrel, but hey pvc is uber cheap.

[Dornep]

Use a wooden dow or rebar and a funnel.

Stick the wooden dow or rebar through the smaller hole in the funnel and then pour the concrete mix around that. Once it's cured you can cut or grind the dow/rebar off to a point after you push the slug out of the funnel.

A concrete slug travelling down your barrel at several hundred (hopefully) FPS will grind that baby down in a heartbeat.. So it better be smooth as a babies crack.

[Novacastrian]

Yes but he also mentioned quickcrete which definatley
would screw up your barrel, but hey pvc is uber cheap.

Yeah lets put abrasive slugs through our highly VALUABLE barrels.
Sounds like a GREAT idea to me.
By the way i'm being sarcastic.

Surely you can think of a better material to use than bloody concrete Why not try aa batteries or some such.

[silverdooty]

cone shaped dixie cups with a washer in the base, then fasten it to you mold and fill with something else other than quikrete. it is too abrasive.

[miskaman]

Say you have a 2" barrel. Then take a piece of 1.75" PVC and fill the middle with concrete. Make the pointed tip the way silverdooty said.

[noname]

There's just the slight problem of 1.75" PVC not being manufactured....

[jackssmirkingrevenge]

Having a pointed nosecone won't have them flying any straighter, to achieve this you need a hollow tail - here's a suggestion on how to achieve it.

[spudgunnerwryyyyy]

Go jsr, that us exactly what i was thinking. Now we could make a pointed tip made out of epoxy. w00t

[jackssmirkingrevenge]

To make a pointed tip all you have to do is add another cup to the top of the pipe with a hole on top to pour the concrete through, why waste precious epoxy