Why are my bullets growing?

[fiatmom]

I took my Sharps out for a day of shooting and got a big surprise.The cartridge would not chamber. When I removed the shell I noticed the nose of the bullet had been engraved by the lands. I measured the bullets just in front of the first band to get a reading on the nose since I had sized the bullet. There was a .003 inch difference between the bullets that fit and those that did not.
What could cause this? could it be differences in alloy , or the mould heating and expanding. The mould is a Lyman Postall bullet of 530 grains.

[btroj]

Where they all poured from the same pot? It could be a difference in alloy but that is a huge difference.
I would be willing to get some were cast when something was holding the mould slightly open. Sounds like a mould that was inadvertantly "beagled".

[44man]

It is because you have an alloy with antimony. They will not only harden over time but will also grow.

[Blammer]

I suspect the cause is one of two things.

When you sized it you smushed the nose a bit to make it fatter.

When you loaded it, you smushed the nose a bit to make it fatter.

[Recluse]

Dang near every boolit I cast or have ever cast has antimony in it/them, and have yet to grow--and some of them have been cast and stored for over ten years.

Agree with Blammer.

:coffee:

[williamwaco]

When I removed the shell I noticed the nose of the bullet had been engraved by the lands. I measured the bullets just in front of the first band to get a reading on the nose since I had sized the bullet. There was a .003 inch difference between the bullets that fit and those that did not.
What could cause this? could it be differences in alloy , or the mould heating and expanding. The mould is a Lyman Postall bullet of 530 grains.



1 Bullets do not grow. Not even bullets with antimony.

2 You mentioned that only the nose of the bullet was over size.

If you still have that cartridge, pull the bullet and measure the diameter of the driving bands.

I expect you got a splash of lead on the face of your mold block and the mold did not completely close. The bullet was oversized but when you sized it, the body was corrected. Sizing would not however correct the nose of the bullet. This issue has been well documented here. Mostly with Lee molds but any mold can be held open a few thousandths.


See:

http://castboolits.gunloads.com/showthread.php?t=130224

http://castboolits.gunloads.com/showthread.php?t=128514

http://www.reloadingtips.com/pages/missing_tumble_lube_grooves.htm


for antimony bullet growth over time, see:

http://www.reloadingtips.com/pages/exp_110921a-cast-bullet-expand.htm

One more possible consideration is that perhaps the bullet just was not seated deeply enough when loaded?

And- blammer is just as likely to be correct, I am just offering alternatives.

[Sonnypie]

Porous lead.
When it was hot, it was dried out.
But then over time it took on moisture and swoll up, like a sponge will do when wetted.
Only when lead does it, it does it slower than a sponge does.
So you will need to melt it back down, and only cast what you will shoot within a weeks time.
Otherwise it is apt to get swoll up again.
Or you could send it to me and I can dehydrate it for you, for a small toll. Say 50%?
I mean, such a deal! Eh?

Yep, porous lead I betcha. :kidding:

[fiatmom]

The bullets were thumb pressed into unsized cases but when sizing some were harder to push through. I would agree that the flashing problem may be the cause. It was a while ago but I thought I had to wipe some lead off.

[fiatmom]

Sonnypie vat a deel maybe you could do it wolesale? : )

[btroj]

Are the bullets married? That always causes fattening.....

[williamwaco]

The bullets were thumb pressed into unsized cases but when sizing some were harder to push through. I would agree that the flashing problem may be the cause. It was a while ago but I thought I had to wipe some lead off.

Fiat. That statement is a dead giveaway. That is exactly what happens when something holds the mold open a few thousandths.

Check your mold faces for anything stuck to them. Also check your alignment pins to be sure they are seating properly and not binding. Check the edges of the cavities for a small burr. Check the handles for proper fit. Check the sprue plate, be sure it is flat on the bottom and has no burrs. When you are sure it is closing properly, hold the mold up to a very bright light with the cavities opening toward your face so you can look into the cavities. If the mold is open even a thousandths, you will be able to see light through the crack in the nose of the bullet.

[mpmarty]

Naaa... The brass contracted on the boolit shank and "squooze" lead into the noze making it larger. :=)

[geargnasher]

1 Bullets do not grow. Not even bullets with antimony.


And- blammer is just as likely to be correct, I am just offering alternatives.

Actually, boolits can and do grow as they harden, it just depends on the alloy. I've documented this several times, as have several other members here. Usually, clean foundry alloys and similar stuff NOT derived from unknown scrap, babbit, wheel weights, battery terminals, pewter, dive weights, etc. don't do anything funky after being cast, but much of the time my WW alloy will grow about 1% in the first couple of weeks after casting if air-cooled. This just goes to show once again that situations differ and absolute statements based one one person's tests don't mean much for the rest of us not using exactly the same components and equipment.

I fully agree with the assessment that this is probably a casting issue and some of the boolits were accidentally "Beagled" by flashing on the mould faces.

Gear

[nanuk]

make sure you NEVER rub them with any toilet tissue.....

that seems to make things get fatter

[ku4hx]

I had this happen once when using a compressed powder charge in a taper crimp pistol cartridge. Switched to a different powder so as to have no compressed powder and the problem vanished.

[ku4hx]

make sure you NEVER rub them with any toilet tissue.....

that seems to make things get fatter

Told your wife that lately? Still have all your fingers and such? :kidding:

[44man]

make sure you NEVER rub them with any toilet tissue.....

that seems to make things get fatter
Is THAT what happened to my wife? :veryconfu Need to find her old Sears catalogs I guess.
But yes, my WW boolits grow, My .476" booits will reach .478". I have to size them again or I can't chamber them.
Softer lead will not.
The thing is, we don't all have the same lead.

[462]

I, too, have had to resize previously sized and lubed boolits, because they had become fatter.

[crabo]

Not to change the subject, but wouldn't a 20-1 lead to tin alloy work better in that Sharps? I don't think those would grow.

[williamwaco]

Actually, boolits can and do grow as they harden, 1) it just depends on the alloy. I've documented this several times, as have several other members here. Usually, clean foundry alloys and similar stuff NOT derived from unknown scrap, babbit, wheel weights, battery terminals, pewter, dive weights, etc. don't do anything funky after being cast, 2) but much of the time my WW alloy will grow about 1% in the first couple of weeks after casting if air-cooled. This just goes to show once again that situations differ and absolute statements based one one person's tests don't mean much for the rest of us not using exactly the same components and equipment.

I fully agree with the assessment that this is probably a casting issue and some of the boolits were accidentally "Beagled" by flashing on the mould faces.

Gear


Gear,

We almost never disagree but this time I must respectfully disagree.

1) It MAY depend on the alloy. I have only tested three alloys.

2) I have tested air cooled wheel weights twice. No growth.

Give me an alloy formula to test and I will try again. Frankly I would like to see this phenomenom because there are so many people who refer to it.

I have a ACWW test underway right now. It consists of daily measurements of 24 .357 158 gr SWCs 16 unsized and 8 sized to .357. Today is day 40 of this test and there has been NO growth in diameter or length. ( One "expert" even told me they would get heavier as they grow. )

357shooter told me growth occured about week three and then went away. He also said he only measured his bullets weekly.

I plan to keep my current test going at least three months. I am now considerably beyond week three.

I agree completely with your assessment of absolute statements. "No absolute statement is worth a D---, including this one."

That said, the issue I was addressing was the absolute statement ( repeated often on most of these forums ) that "BULLETS CAST OF AN ALLOY CONTAINING ANTIMONY GROW WITH TIME" All I am doing is refuting that absolute statement. I only need one test to disprove it.

Show me an alloy that grows.
Let's get to the bottom of this issue. . .

[btroj]

I wonder if some of the growth could also be diameter related?
Do bullets under say 40 cal not grow while those over 40 do? Could the difference in rate of cooling have anything to do with it?
I have not had a situation where I KNOW a bullet grew but that certainly doesn't mean I think it can't happen.

Looks to me like more testing needs to be done. Bad thing is it is probably very alloy related and who knows what the "magic" mix is?

[Blackwater]

I ran into a similar situation with my 1885 Brng BPCR when I first started shooting it. I was compressing the powder with the bullet when I seated it. The pressure of compressing the powder squished the bullet out a bit, and some ctgs. just wouldn't seat in the chamber no matter how hard I tried. I got a compression die to compress the powder charge with, and no more problems.

[462]

My instance of boolits growing fatter involved Lyman 429421's. They were cast in the winter of 2010 of 100% wheel weights, dropped at .433+" and air-cooled. After setting for a day, they were sized and lubed in a Lyman .433" sizer die, then stored.

Earlier this month, I went to load some and they wouldn't fit in the case mouth, which had been expanded to .433", by a custom M-die expander plug (first step .431", second step .433"). I removed the lube from a couple boolits, cleaned and measured them. They measured .434". I re-ran the boolits through the .433" sizer and was able to load them.

I'm neither a chemist nor a metallurgist, so I don't know, nor can I explain, the how's and why's. All I know is that it happened.

[Stick_man]

Stop watering them. Soon they will wither up and die. Also, maybe cut back a little on the fertilizer. That should stunt the growth some.[smilie=f:

Mine tend to grow quite a bit on one end, but that is usually after firing them and hitting something pretty solid.

[leftiye]

Thay's yung yet. Thay'll stop growin' when thay mature.