Is this normal for bullet weights when casting?

[blasternank]

I got a Lee 515 mold. It is a .510" diameter bullet and is a 500 grain mold. Anyway, my dad casted me up a couple hundred bullets as I am just getting all of my stuff together and will be casting soon myself. Anyway, I weighed the bullets and most came out around 468 grains give or take a couple grains. The heaviest was about 476 gr. and the lightest 455 but ones like that numbered just a few. They all have come out looking great-there were some that didn't and those were the first ones like usually happens.

Is it normal to have bullets that light come out more or less consistently that much lighter out of the mold? Could it be the way they were cast? Or is that the way lee molds are? Some come out light. What do you think it could be?

Thanks for your pointers and expertise.

[Moonie]

The weights listed are for the alloy the mold maker uses, not necessarily what you are using, and usually it is just a close approximation.

[peerlesscowboy]

I wouldn't worry too much about the difference between LEEs nominal weight and you'r actual average weight, that could be caused by using a different alloy than LEE or a number of other factors. I'd be more concerned with the rather WIDE variation in weights of the bullets your dad cast. Is he an experienced caster?

John C. Saubak

[Iron Mike Golf]

+1 to what Moonie said. Higher lead content = heavier boolits. They will also shrink more upon cooling. More tin and/or antimony means a lighter boolit of larger final diameter.

Lee weights and diameters are based on a 10:1 lead to tin alloy, except for round ball and Minie ball molds, which are based on pure lead.

[blasternank]

+1 to what Moonie said. Higher lead content = heavier boolits. They will also shrink more upon cooling. More tin and/or antimony means a lighter boolit of larger final diameter.

Lee weights and diameters are based on a 10:1 lead to tin alloy, except for round ball and Minie ball molds, which are based on pure lead.

Interesting. Thanks for all the replies!

[fredj338]

The larger the bullet the more the variation, but if cast from the same alloy, more than a 1% variation from the average can mean a couple things IME. Bullets really light could have internal voids &/or grooves not filled out, neither good for accuracy. The heavier ones could be finned or have flashing on them that adds to the weight. I don't weigh any of my practice bullets, but bullets for long range accuracy or hunting get weighed & anything out of the 1% range get used for practice bullets or returned to the pot.

[mpmarty]

Inconsistent weights are usually the result of inconsistent casting technique.

[1Shirt]

Agree to a point with MPmarty. However, the ones that are real lite, quite often have voids or hollow spots, particularly on heavy weights.
1Shirt!:coffee:

[Hanzerik]

Newb here, started casting bullets yesterday after spending a few days melting down my collection of WWs. My mold is a RD TLC432-265-RF six cavity.

I think I have found the sweet spot as far as temperature "7" on my Lee bottom poor pot. But it takes a few cycles to get the mold up to temp. But I have noticed that after I start to get good bullets, the spruce cut on the bottom is at first shinny for the first few cycles, then becomes slightly recessed and rough looking and the bullets start to become frosty, but nicely filled out. Is this a problem with me not letting the mold cool off, or is the melt changing properties as the level in the pot is getting lower? Can heat changes cause a bullet to have different properties, i.e more brittle, lighter/heavier, etc? These are being made from straight WWs.

I do have one cavity that is giving me problems with not dropping freely, I think there is a small burr right at the top of the cavity. A slight rap with a piece of wood on the hinge pin will get it to drop.

[BOOM BOOM]

HI,
That seems like a big weight range.