My boolits are growing?

[Whiterabbit]

So, I have a LEE push through sizer I polished to .4525, sizes the boolits perfectly there. I know it's perfect because they stick in the cylinder and will go through with just a little help from behind via dowel.

So I went thorough a major casting session a few months ago and cast over a thousand of these guys. Gas check, lube, the whole 9. Water dropped hardball (they are for 460S&W).

So I've loaded and shot half over the months. No issues.

Fast forward to Friday, and I was showing off to a buddy how perfect my boolits fit, plunked one into the cylinder and.... didn't fit. It's oversized.

I've shot hundreds of these in this state. My loads are far from max, but of course no pressure signs or issues...

So, do boolits grow over time? given my alloy choice, do I need to start aging my boolits before lubrisizing?

[1johnlb]

Probably, just the boolit fairy keeping your ego in check, because of your bragging.[smilie=l:

Was it just one round or all of them. Did you have any copper in the mix.

[Beagle333]

Hardball is 6% Sb isn't it? My weak understanding is that Sb will grow some with age.

[dubber123]

They definitely grow over time. The downside to waiting to size after water dropping is much increased sizing effort, and you will be sizing a lot of the surface hardening off.

[44man]

Yes they grow, my .476" boolits will reach .478". Smaller calibers grow less.

[runfiverun]

ain't this stuff cool?
wait till you read up on precipitation hardening and Sb content....

[bhn22]

And many alloy combinations will spring back a bit after sizing. They don't just swage down in size, but are compressed. Then the compression relaxes a little, and the bullet gains a little bit on size. Plus as mentioned before, some alloys grow a bit over time as well.

[Whiterabbit]

its not springback, I run them through the sizer (and then lubrisizer) and then they slip right through the cylinder as a perfect fit. Now they are too big, months later? rats.

Yes, the alloy is 6% Sb. I should admit with honesty that my hardball is "lazy hardball", where I use range lead as the base (usully about 1 MFRB worth) and add linotype (usually about 1 SFRB worth) until the Sb% calculated, not measured, is above 5.5%. Then add eutectic solder to get up to above 1.75% tin. So the alloy is actually kinda variable, but always in the ballpart of hardball.

You are right if they grew more they would be hard to size. I'm thinking size once in the LEE sizer to snap on the gas check, then re-size later in the lubrisizer (rather than right away). That would put more stress on the lubrisizer, but I'd only be sizing the grown rate of the boolit.

Make's a man wonder how much the boolits of loaded ammo grow.

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Real question is what is the time line for the "age growth" and when does it stop?

[44man]

They do but brass kind of restrains them, the nose has no restraint though.