When to size air cooled boolits?

[Gunslinger]

The answer to this question has always evaded me for some reason. I know air cooled boolits reach their maximum hardness after 14 days. But does this mean that you should wait 14 days to size them?`

Sizing shortly after casting and then waiting 14 days to shoot them would seem like the right thing to do? Or did I miss something?

[lurch]

I size as soon as practical after casting. Works fine for me. Harder boolits are harder to size is my way of looking at it. Also, sizing after hardening will soften the boolit on the surface. If you need the hardness then sizing after hardening might not be the best thing to do. There are arguments that it matters and that it doesn't really matter since the softening should only occur at the surface. I'd just do what works for you.

[kyle623]

your right, size them before they harden is what most guys say.

[Shiloh]

I size as needed. THere doesn't seem to be a problem with the surface softening. THere does seem to be a little spring back though. I know it seem strange, some of my boolits that were sized and checked, measure more thatn the .312 of the size die.

Shiloh

[1Shirt]

Size ASAP, you won't forget that way, and they are out of the way.
1Shirt!:coffee:

[HORNET]

Some members on here have claimed that alloys with significant amounts of Antimony will have an increase in diameter as the alloy "ages". If sized diameter is real close to the maximum that will fit your chamber, you might want to size close to the time that you anticipate shooting them. This also allows you to change your mind about what size you want (like for a new firearm)...I usually have a small batch sized and lubed in closed storage boxes to keep dust & dirt out with most of a casting batch stored unsized in cardboard boxes.

[Cherokee]

There is generally weeks or months between casting and sizing my air cooled WW bullets. I have never noticed a problem. Sized bullets may wait a year or more befoe loading. I have some ammo I loded over 20 years ago, still shoots great. Also got some cast bullets from back then, gotta load them some day.

[lurch]

I size as needed. THere doesn't seem to be a problem with the surface softening. THere does seem to be a little spring back though. I know it seem strange, some of my boolits that were sized and checked, measure more thatn the .312 of the size die.

Shiloh

That's a good point about spring back. Another thing to remember is that higher antimony content boolits will "grow" as the harden. For air cooled, the amount of additional hardening is minimal. For water dropped or oven heat treated, the boolit will get bigger as the precipitation hardening takes place. My Dad recently observed this with a batch of 45 ACP loads. Heat treated, sized & lubed then loaded. All was peachy. A few weeks later the cartridges wouldn't chamber... He should know better as he's the metallurgical engineer, not me.

[454PB]

I have posted here before that I recently came across about 60 pounds of unsized .45 SWC boolits I cast of WW alloy and water dropped over 25 years ago. Diameter is .454", just as it was when they were cast, and they test 14 BHN.

They softened some, but diameter is unchanged.

[243winxb]

I know air cooled boolits reach their maximum hardness after 14 days. How do we know this? Some say water dropped bullets do, they don't. See hardness test bottom of page. http://www.freepatentsonline.com/5464487.html
After 8 days, 1 1/2 months and 2 months, hardness tests were again performed on these samples and these tests revealed that the hardness was essentially unchanged.

[243winxb]

THere doesn't seem to be a problem with the surface softening. A lead tin alloy containing No antimony will soften over time. Sizing of a oven heat treated/water dropper bullet will work soften during sizing, but only the outer area of the bullet, the inter bullet remain hard.
THere does seem to be a little spring back though. I know it seem strange, some of my boolits that were sized and checked, measure more thatn the .312 Spring back, diameter, is possible depending on the alloy used. See Lyman's website under FAQ. The only alloy that will "grow" in diameter(.0005") is one containing more than 50 %+ Bismuth in a lead base alloy. http://www.alchemycastings.com/lead-products/fusible.htm