Cast Core Voids?

[DonH]

A question concerning swaging bullets from cast cores: if a cast core contains a void will the swaging process eliminate the void? TIA

Don

[Reload3006]

well Yes and NO. if you bleed off some lead obviously you have collapsed any hole that was in the lead. But its not solid either. if stuck in a jacket it probably wouldn't be a problem on a solid lead bullet it can be a problem.

[martin]

DonH,

Although I don't have a direct answer to your question about eliminating cast voids in the swaging process, I would suggest that the way to find out would be to swage a few with voids and weigh the resultant cores. If a sample of swaged cores is within .1 grains, I think you can prsume that the voids have been mitigated.

In other words, if the resultant cores are the same weight it would seem that the voids have been swaged out. If the resultant cores are not the same weight then the voids have not been eliminated.

If you try this out, maybe you could post the results.


Martin

[MIBULLETS]

I think that would be a good test as well, assuming that you know which ones have the void. I assume some of the voids would be hidden in the core. I am not a caster so I might be off here. I have thought about this before since extruded wire can have voids also. Probably not as often, but it happens especially if the wire was formed by splicing lead in the wire forming die.

[algunjunkie]

I would think that it would have to be a large void for it to not be swaged out during the forming process. I have casted thousands of cores and then swaged them and have never noticed any difference in the final weights. But then again I am only swaging a 223 bullet it might be more prominent in the larger calibers.

[Seth Hawkins]

With the amount of pressure being applied to the core, I seriously doubt a void of ANY size WOULDN'T be eliminated, irrespective of the core's size. Stop and think for a moment about the amount of pressure being applied to the core. It's a butt load, whether you're making a naked bullet or a jacketed bullet.

I have no data to support my claim, just intuition. I have a Corbin CSP-2 press that I use to make .44-cal PP rifle bullets, and even with all of the leverage of that press's design, it still takes a fair bit of effort to get the initial "flow" started. And I use pure lead.

I cast my cores for that bullet because I'm shooting a relatively light 407 grain bullet, and my core mould can crank those out four at a time pretty quick, and I'm not concerned with how they look, because they're gonna get swaged to their final shape. They just gotta be heavier than 407 grains. I save my lead wire for heavier bullets. I spot check my bullets after swaging, and haven't found one yet that I suspected of having a void in it that was left over from casting. They've all passed QC by coming within +/- 0.2 gr.

[Reload3006]

if you put your lead in a jacket its no problem. If your just going to shoot a lead bullet big problem. For example take Lead shot you can dump a bunch in swage a core and it will look solid but if you drop it it will fall apart. So yes you will squeeze the void out but the lead will not be a solid piece either. If its in a jacket no problem unless you want a bullet that isnt frangible.

[DonH]

I am a bullet caster and (I think) a pretty good one, casting mainly bullets for competitiion. I visually inspect every piece and my standard for acceptance is rigid so any bullet with an external void would be automatically be rejected. I have been told by those more capable than I that it is very difficult to cast a bullet with a tiny internal void somewhere in it. Weighing the bullets eliminates any gross discrepancies but a remaining void within the bullet could (and I'm sure does) cause a bullet to be imbalanced.

I posted here because (1) Swaging intrigues me and (2) because of a desire to know if slightly swaging a cast bullet could eliminate most, if not all, of those tiny voids.

[Reload3006]

it can help I have hollow pointed and sized cast using my swage gear.

[MightyThor]

DonH,

Although I don't have a direct answer to your question about eliminating cast voids in the swaging process, I would suggest that the way to find out would be to swage a few with voids and weigh the resultant cores. If a sample of swaged cores is within .1 grains, I think you can prsume that the voids have been mitigated.

In other words, if the resultant cores are the same weight it would seem that the voids have been swaged out. If the resultant cores are not the same weight then the voids have not been eliminated.

If you try this out, maybe you could post the results.


Martin

This won't tell you what you need to know. An ounce of lead weighs an ounce regardless of how many air pockets, holes or irregularities in shape or size. Swaging the lead changes the dimensions of the lead billet, but does not add or remove material so it weighs the same no matter what.

[martin]

Mighty Thor,

I can see your poiint if one is using a swaging die that does not bleed off lead to get to a finished core weight and size. I was working from the presumption that he was using a squirt die to size the cores.

All of my rifle die sets use squirt dies and with rare exception the cores come out very close (0.05 grains) in final weight. I consider this critical as it establishes the weight variation of the final bullets that I use for bench rest.

Martin

[MightyThor]

Martin,
I guessed that you were thinking about the core swage process with a bleed off die, and you and I assume the same thing. That is, that the pressure to swage a core is going to collapse any air pockets in a core blank. But just weighing before and after the process will not tell you anything about the internal structure of the core after swaging. It will only tell you how much lead has been bled off through the holes.

If you were instead to weigh the squirted lead, you might have some idea of the difference in structure between a group of core blanks, but you could still not be assured that known defect had been removed as opposed to reduced without a complicated calculation of the volume of the defect and the mass or weight of lead that would fill the defect.

Based upon my experience with core creation I am certain that any internal irregularities, pockets etc are no longer present in a core after swaging or seating it, but to be scientifically certain that this is the case a person would likely have to section the core after the process to determine that a core blank with a know defect had in fact collapsed that defect.

[Reload3006]

if you have a void it has air. air can be compressed but not eliminated. you can make the void a lot smaller and in practical terms eliminated but its still there LOL.

[martin]

Gang,

I am not disagreeing with any of the previous postings, however, if the core swaging process is producing the same diameter and length of core (thus volume) and the wight is not the same then there is a difference or void someplace given that the density of the lead (alloy) remains the same. If the weights are the same then most likely there is no void or all the voids would be exactly the same.

Does this make sense?

Martin

[MIBULLETS]

I agree with that statement. Same volume, same weight, must be the same whatever same is.

[MightyThor]

Right, I don't disagree with Martin, just not sure how you would get a core blank that would squirt lead out the bleed holes while still containing some sort of measurable void. But I certainly agree that two lead cylinders that have the exact same dimensions but different weights must have one with air in somewhere.

My initial response was premised on my experience that pressing on the lead in the core die will squash the blank into a uniform shape every time regardless of irregularities. In my cast core blanks the outside is often rough and may even have a void, but upon swaging, I get a uniform core that is the same shape and weight as the one before and the one after. (within tolerances) I have never had one that squirted lead but did not fill out the full volume of the core die and thus weigh within the expected weight.

[MIBULLETS]

I think the question is, if there is a void in the center of the core before the squirt die, will it come out of the core? I don't think it will. I think like someone else mentioned, that it will be compressed. So depending on how much it is compressed and the size of the void, if any remains after compression is where we could notice a difference.

I agree that if a void is at the side of the core or close enough that during compression it will most likely escape and no longer be in the core, just not sure how well a void can migrate through a larger amount of lead under pressure.

[Reload3006]

I think the question is, if there is a void in the center of the core before the squirt die, will it come out of the core? I don't think it will. I think like someone else mentioned, that it will be compressed. So depending on how much it is compressed and the size of the void, if any remains after compression is where we could notice a difference.

I agree that if a void is at the side of the core or close enough that during compression it will most likely escape and no longer be in the core, just not sure how well a void can migrate through a larger amount of lead under pressure.

That is what I was trying to say LOL you said it much more clearly.