Help with Ice Slugs

[Pete Zaria]

I've made a few molds out of 1.5" ABS (same size as my main barrel) with test plugs for end caps. I fill them up with water and freeze them overnight. The problem is, the water (obviously) expands when you freeze it, and the ABS mold actually streaches about 1/8th". Because of that, it's nearly impossible to get the ice slug out of the mold. Even if you do manage to push it out, the ice slug doesn't quite fit in the barrel, so you have to let it melt a bit, and by that time it doesn't have a very tight seal in the barrel.

Does anyone have a better way to make ice slugs?

As a side note, what about making a mold that had rifling in it, to make rifled ice slugs?

Peace,
Pete Zaria.

[boilingleadbath]

Rifling the slug won't do any good if you don't have a riffled barrel. (shotgun slugs are "riffled" because of tradition)

Well, it would help a bit if you used PVC instead fo ABS for your molds; PVC takes ~25% more force to stretch the same amount.

Other than that, I don't have a tested solution to the oversize problem; I just let it melt as you do - so that it's undersize - and put a chunk of polystyrene behind it as a sabot... and we'v never had a discussion of this problem.

Perhaps one could prevent swelling by freazing it from the bottom up; ie, insulate the pipe peices on the side and the top, and freeze them from the bottom.

[jrrdw]

Use less water to allow only the ice to expand. When useing rifled slugs in a shot gun you should be useing a smooth bore barrel, and vice versa. Sabot slugs are made for rifled barrels. You can call any gun smith on that one. "NO BRAG, JUST FACT" Walter Brennon from The Guns of Will Sonnett.

[Pete Zaria]

You're correct about shotguns and slugs. A rifled projectile in a smoothbore barrel is slightly more accurate, but I doubt it'd be worth the work.

I'll try using only half a mold full of water and see if that helps at all.

Is the inside diameter of 1.5" PVC the same as 1.5" ABS?

Would bondo or plaster of paris expand as much?

Any better ideas on a cheap, easy molded projectile?

Peace,
Pete Zaria.

[jrrdw]

Bondo doesn't expand at all that i know of, maby shrink a hair like wax, but if you mix to much hardner in it will crack, i've done a lot of work with bondo best to work with when its warm outside, i have a gallon of it in the shop rite now, i even started a thread called "good ammo" about it. Got good debate about it to. Never worked with plaster, can't be to different from bondo. That would be a heavy slug, plaster.

[sgort87]

The best way I have found to make Ice slugs is to use ice itself!

First you make a slug mold and apply a good ammount of car grease on the sides to allow a little expansion room and easier removal. Then you take a container of water and stick it in the freezer and cool to the point where it ALMOST freezes. Then fill your mold up with ice cubes and the rest is filled in with your almost-ice water.

This will expand much less because the ice cubes have taken up most of the room and are already expanded. The reason you need chilled water is so the ice cubes wont melt.

These slugs are very easy to work with and require nothing more than a pair of hands most of the time.

Another thing you can do is toss a 20 oz soda bottle in the freezer and allow complete expansion which will fit right into 3" pipe. (Coke bottles are a very tight fit.)

[rna_duelers]

Just stick the mould in some hot water to melt it around the edges a bitthen its slightly smaller.

[)DEMON(]

what if you could get a liquid that dosnt expand when it freezes?

[x.X.Cpt.Rollhart.X.x]

what if you could get a liquid that dosnt expand when it freezes?

I think that the first idea of using Ice slug is to save money ....

[boilingleadbath]

<i>Most</i> liquids don't expand when cooled. Common ice is somewhat unique in that aspect; and that's due to it's crystal structure. (infact, other arangments, although they can't occur at atmopheric pressure/temperature <i>are</i> denser than water. See the wikipedia artical on "ice")

However, there are no liquids that are as cheap as water, and few that freeze at a temperature that would make them acceptable for our uses.

As to plaster, from the wikipedia artical, it supposedly doesn't swell very much during curing. My tests indicate otherwise, alhtough "Plaster expands while hardening, then contracts slightly just before hardening completely"... I may not have waited long enough.
(doubtfull. I know plaster is used to plug fireworks.)

The botom freezing meathod sounds promising, and might be my next project. I'll let you guys know how it turns out.

[Pete Zaria]

sgort87, I'll try your idea today. What kind of grease are you using?

BLB, thanks for your input. What would this forum do without you?

A large part of my reason for wanting to use ice slugs is, indeed, cost saving. Also, though, they're easy to make, fun to shoot, explode on impact, and they won't fly too far (I have neighbors 3-400 yards away, so I can't shoot golfballs around here).

I guess my other question is, what about making a mold thats intentionally a bit undersized, to compensate for expansion?

Peace,
Pete Zaria.

[sgort87]

Well basically the greese and using premade ice to start with is supposed to compensate for the expansion.

The grease I use is just some tub of car grease that I'm sure you could find at Auto Zone or something easily. I doubt it costs much and should last a decent amount of time. I advise you wear at least one latex glove to save you from cursing sessions.

[boilingleadbath]

*Pops test rounds in freezer*
Ok, I have started freezing a 2" diameter ice slug cast with icecubes, one cast without icecubes but with salt, and one without either.
I will de-mold and measure them about this time tomarro.

[boilingleadbath]

Ok, tests are done...
All techniques produced a slug within .01" of each other, with the salted and ice-cube enriched rounds being smaller. I can't provide numbers as to how much they vary from the normal ID of the pipe, or numbers more accurate than that, because I was forced to use a plastic caliper, because a metal one (being thermaly conductive) would melt the ice I was trying to measure... making the measurments very inacurate.