Trying to recover some lost info!

JWFilips

Well-Known Member
"A long time a go..... in a place far far away!" There was a thread and either it had some posts from Ian ( Geargnasher) or fiver....explaining how casting temperatures affects bullet size and weight per any given alloy.
Any of you folks want to re-record it here? I seemed to have lost my data file....and aging does not help my memory
 

462

California's Central Coast Amid The Insanity
In my experience aging only helps Beef to taste better.
And wine.
That said, my daily glass of red is somewhere between two and four years old. Even with wine, I'm frugal.
 

Glaciers

Alaska Land of the Midnight Sun
Yeah you guys are a lot of help.
I would be very interested in this info as well
 

Spindrift

Well-Known Member
This, maybe?
 

popper

Well-Known Member
Shrinkage due to alloy temp. Hotter comes out smaller. Plus if you cast a lot, mould gets hotter and dia changes. Don't think it is something that gives guaranteed results.Mould material makes a difference too.
 

462

California's Central Coast Amid The Insanity
Yeah you guys are a lot of help.
I try.

Diverting back to Jim's question. My fallible memory bank recalls that that other forum's theperfessor, our KeithB, wrote a very factual essay, including measurements, pertaining to various alloy temperatures and bullet size. A search should uncover it.
 

Joshua

Taco Aficionado/Salish Sea Pirate/Part-Time Dragon
How about this one.
 
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JWFilips

Well-Known Member
Seriously; need Ian and fivers input here : sorry guys but my mind is clear enough to remember the sources
 

Ian

Notorious member
Hotter mould smaller bullet, hotter alloy smaller bullet. If you get too hot with either the bullets will hourglass. Hot mould cool alloy yields about the same as cool mould hot alloy but the way it fills will be different.
 

Rick

Moderator
Staff member
^^^^^^^^ This.

But unless your using a really high Sb alloy I think you'll find with careful checking with a good mic that your differences will be in tenths of a thousand and not in thousands of an inch.
 
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Ian

Notorious member
That's right, Rick. I don't worry about it. Usually I cast with something akin to wheel weights and run my alloy between 690 and 730⁰ depending on how much heat I'm trying to keep in the blocks. Casting tempo and forcing a little air on the sprue plate cooling (sometimes) keep the moulds at whatever temperature makes them happy. The results are what they are and get sized appropriately, noses too as required, or a better mould is ordered from Tom. I see a lot more size variation from slughtly different alliy constituents than I do from temperatures; it's a pretty narrow range that gives me the best bullets so I go with that and work with what I get as a result.
 

JonB

Halcyon member
This isn't the thread you are looking for, but it reiterates that casting with a Hot mold will make a slightly smaller bullet. I found it a great way to correct the gas check shank size with this particular troublesome mold.


 

StrawHat

Well-Known Member
And wine.
That said, my daily glass of red is somewhere between two and four years old. Even with wine, I'm frugal.

Either you have a really big glass or take very tiny sips. My glass usually disappears with my meal. Now, a glass of Port, that I will sip all evening but 2-4 years! Wow!

Kevin
 

462

California's Central Coast Amid The Insanity
Either you have a really big glass or take very tiny sips. My glass usually disappears with my meal. Now, a glass of Port, that I will sip all evening but 2-4 years! Wow!

Kevin
:rofl:
 

popper

Well-Known Member
Melt temp 720F cooled to 200F (solid) - mould temp 400F raised to 500F when poured.
30 cal mould circumference (~1", 0.311) grows ~0.001". Alloy circumference shrinks 0.005-0.008" depending on amount of Sb. Convert to dia = 0.3085 shrinks.
Mould = 0.3113 expands but cools for next pour. Effectively the alloy temp and composition is all that matters. Steel expansion is less than Al or brass.
 
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JWFilips

Well-Known Member
OK Now: Does a higher percentage of lead in an alloy cast a larger or smaller bullet? I know the bullets will be heavier
 

Rick

Moderator
Staff member
Tis antimony that increases the diameter. With it bullets will be a tad smaller in diameter.
 

Winelover

North Central Arkansas
Tis antimony that increases the diameter. With it bullets will be a tad smaller in diameter.

:headscratch: I think you may want to rethink that statement.

Most of the bullet makers, like RCBS and Lyman, state that their moulds are calibrated with Lyman #2. That is the reason most of their moulds cast small. Lyman # 2 is significantly harder than pure lead, due to greater proportions Sn and Sb. The harder the alloy the less it will weigh.