Suggestions for a heavy duty saboted dart

[FighterAce]

I'm half way there with my latest .50cal and its time to think about the ammunition....

I have a general idea how a saboted dart should look like but I ran into a problem with sabot material. I cant find anything that can be casted, is light, easy to work with and easily mass produced.
For the tails I'm thinking about perfecting this method http://www.youtube.com/watch?v=9hbijG4FKSk&feature=channel_video_title but I'm not sure how high I can take them.

GGDT estimates speeds up to 222m/s for a 4g projectile. Pressure around 700psi. Could milk jugs take that or should I get thick polyethelyne/polypropelene sheets?

I just realized I could optimize the tail for balance and not worry about the diameter if I use sabots 

[Forum Admin]

If you use sub caliber cones, the milk jug might work. You might even be able to use a similar technique to mold sabots as well, I thought of that one as I was going to sleep last night, so I'm not sure if that's a good idea or not, I just got off a 14 hour shift. 

[FighterAce]

To mold sabots from HDPE I'd need an injection molding machine... which I can't afford right now... buying too much crap already  I was hoping to find something like plaster but a lot lighter
Or some kind of foam? Expanding foam?

[Forum Admin]

I tried expanding foam, the kind you use for insulating cracks in houses, but it didnt work for me.  I'm thinking along the lines of heating a milk jug until clear, pressing a sub caliber rod into it, then inserting into a piece of barrel material before it completely cools. I havent tried it before, but it works in my mind.  lol I've been working on woodgas generators lately and putting in a garden, havent had much time for airguns. Kinda miss it...

[Pellethuntr]

Ditto on that Admin.. I've been busy with work and trying to fix up a car I just bought.. But I must confess powder burners are consuming a lot of my time as well haha I'm learning a lot from building them that I hope to use when I finally get to build my beast.. I recently picked up a .50 barrel and action to use and I am hoping to get some 4130 for my reservoir soon.. good luck Ace can't wait to see your finished AG

[Forum Admin]

This has been bugging me greatly, so I had to try it out for myself. I used a heat gun to soften the milk jug. The tail end of a drill bit is used to form the plastic around. Before the plastic cooled, I pressed it into a scrap piece of barrel material and left it there to harden. I pulled it out and made two cuts across the top to form a cup type sabot. If you were to soften the ends and bend them downward, they could hold the dart centered in the barrel... Here are some pics of the setup and the sabot:

[FighterAce]

I just realized that the sabot has to travel from the end of the inner barrel to the start of the suppressor without separating... and thats like 15cm so its not gonna happen.
I don't know how I missed this flaw. My feeding mech+suppressor is not for sabots..

Back to square one...

[mouz]

i would suggest paper cone and FIBERGLASS tape darts, they are remarkably strong.

[FighterAce]

In that case, with strength comes weight and thats the last thing I need.

I'll think of something.... maybe I could combine light and heavy... strong and weak...

[Forum Admin]

one thing about the cup sabot i made is that it is thicker and stronger than the old cones i used to make. It is still very light. Perhaps you could round the end of the bit to lessen drag. I still think fins are the way to go myself. Lol the sabot separation with your suppressor does pose a bit of trouble though

[mouz]

that is why i use fiber tape, not 2 pounds of duct tape.

[Bikewer]

I was thinking of a discarding-sabot to fire sub-caliber ball bearings.   Initial experiments with foam cut to bore-size, a simple cylinder with a cup for the ball, and then two halves of a cylinder on top to hold everything in place.

Problem... Haven't found the right sort of foam yet.   I tried closed-cell insulation stuff, but it got shredded on firing.

McMaster-Carr shows a bewildering variety of foam products available in 1/2" cylindrical stock... But not much in the way of description.   Wish I could find a suplier locally.

[josephlys]

Has anyone made a discarding sabot out of Styrofoam and gasoline/acetone. Styrofoam is just plastic with lots of air bubbles in it, the gasoline is a solvent that melts the Styrofoam and forms a lightweight, dense and strong plastic. You can mold it to desired shape and diameter using an unwanted barrel, just as you do in hot glue.
This maybe good?  

[BrunoBrazil]

I made ??a table for the airgun scopes with styrofoam in gasoline DISSOLVED OXYGEN