hot casting=light boolits??

[irishtoo]

i noticed this morning as i weighed the boolits i cast last night, that the frosted ones were lighter than the smooth shiny ones. i now have a digital scale and can see the difference. interesting, learned something. time to by some more stuff and refine my process. irishtoo

[Don McDowell]

A good lead thermometer and a set of the locking mould handles will eliminate most all of the rejected bullets.

[irishtoo]

thermometer is on the list, but i never seen locking mould handles. is that a factory item or a diy?

[Don McDowell]

They are a factory item, altho made in a one man shop. http://www.buffaloarms.com/Detail.aspx?PROD=159278&CAT=3847
In addition Shiloh carries these and another similar one by another outfit, but I have no experience with those , just the Cabine Tree ones.

[ACrowe25]

Seen the exact same thing... Wondering if it is due to the Pb molecules them self. Could a higher temp allow them more movement when liquid and therefore less molecules within the same area once cooled? Some basic chemistry applied there, should hold true?

[JSnover]

Did you measure the lightweights? Lead is like everything else, more heat = more expansion. The sprue is all of the lead that didn't fit inside the cavity. When the boolit cooled, it shrank, so as it is lighter it should also be smaller.

[Springfield]

Pretty sure it is higher mould temp, no lead temp, that is causing the lighter bullets. I see this on some first pours when I have preheated the mould too much. Frosted bullets that are smaller, can really be noticed when sizing, they barely touch the sides of the sizing die. I have always assumed it was the moulds expanding as it was too hot, everything settles down when the mould temp lowers, nothing changed with the lead

[mikeym1a]

I've never noticed that with my casting; but then, I've never looked for it. The only time I've had boolits noticeably heavier is when I didn't get the mold fully closed. Have you checked for little lead specks between the mold halves? I don't seem to ever get 'slivery' boolits, except for when the mold is still a bit cool. After the mold gets properly hot, the 'frostiness' appears. I've learned to heat the mold on a burner on the stove to get it properly hot. I don't get good fill out until then.

[nanuk]

if the mould heated and expanded, the boolits would be larger/heavier and get smaller as the mould came down in temp.

I am leaning to the hot alloy = expansion idea

[John Boy]

Irish, lighter frosted bullets v heavier shiny bullets can be caused by several factors. To give a factual reply without having been provided any details is meaningless.
You have to observe both the shiny & frosted bullets for differences other than the END RESULT - frosted ones are lighter. Basic answer is the frosted ones didn't fill out the same as the shiny ones because the amount of melt put in the mold was different... which leads to how you pour and sprue puddle

[John Boy]

Irish - give this article a read - Hints for Casting Good Bullets

http://www.n-ssa.org/NORTHWEST/Casting%20Bullets.htm

thermometer is on the listA Must and here is the best one ...
http://www.teltru.com/p-272-big-green-egg-primo-grill-dome-kamado-replacement-thermometer-lt225r-5-inch-stem-2001000-degrees-f.aspx

[irishtoo]

good article. i bought a thermometer and my weights are much more consistent. fewer rejects. thanks irishtoo