Why are "Frosted" bullets considered rejects?

[milrifle]

I see a lot of folks say frosted is OK. Then there are others that still say they are rejects. I'm still new to this and most of my bullets come out frosted and I use them. I am, however, curious as to why some say they are rejects? I've just never heard the reasoning behind the theory.

[Alan in Vermont]

I have my share of rejects but frosting is not a consideration in my inspection practices. IMO, there's nothing wrong with a frosted boolit that a trip down the barrel won't cure.

[runfiverun]

frosting to me means rounded driving bands/corners and unequal weights.
others say it helps hold tumble lube better.

[rintinglen]

Heavily frosted boolits are almost always undersized, and hence, should be thrown back in the pot to be reincarnated.

Lightly frosted boolits are perfectly useable and in fact, that is the condition I strive for when trying for best fill out and maximum production.

Unevenly frosted boolits are definitely rejects, the frosted area will almost certainly be poorly filled out.

[milrifle]

I would have guessed that rounded corners would be caused by a cold mould like wrinkles? Perhaps I'm wrong. I have never noticed rounded corners on any of my frosted bullets, but I will look closer from now on. In my short experience (All in Lee two cavity moulds), I seem to either get wrinkles or frosting. My theory has been, given the choice, frosting is better than wrinkles. If I could get nice shiney bullets with no wrinkles, I'd cetainly like that, if for no other reason, they're pretty.

[Chicken Thief]

Who said that?
Have never had a shot deer complain, ever!

[geargnasher]

The order of appearance/dimension of typical non-eutectic ternary alloy as the mould temperature increases:

1. Shiny, wrinkled, undersized boolits with severely rounded everything.
2. Shiny, wrinled and sorta filled out edges.
3. shiny, smooth, and filled out sharply, largest size the mould will throw with that alloy (most of the time).
4. shiny, smooth, but edges rounded and severely frosted white. still full-diameter. I reject all of these.
5. Light, satin frost and razor-sharp fillout. The frost will wipe off with a dry rag revealing a shiny surface. This is an easy window of mould temperature to maintain, and simple enough to make a long run of consistent boolits maintaining mould temperature with only the visual aid of the boolit's appearance and sprue freeze time. It also makes an ideal temperature of boolit for water-quench hardening.
6. Same, but starting to shrink the middle bands from excessive heating or pouring too fast.
7. Frost getting heavier, edges starting to get slightly rounded-off again. Entire boolit starting to become undersized.
8. Heavy frost, pitted, sandblasted surface, frost will not wipe off with a dry rag, looks like freshly broken cast iron, edges very rounded. Sprues usually smearing molten lead across the top of the blocks and building up under the sprue plate. Reject all of these and cool the mould.

Gear

[MtGun44]

I try to run at #5 without wandering into #6. Sometimes manage #3, but usually pass through it on the way to #5.

Bill

[357shooter]

Great list. I usually live at number 5 too, rarely getting into 6.

[fecmech]

Thanks for the write up Gear. I have a friend who has just started casting and I will print this and give it to him.

[Springfield]

From personal observation I think 4 is in the wrong place. I can go from perfectly filled and shiny to perfectly filled and frosty. I usually get #4 when my alloy is too hot but the mould is not hot enough.

[DrCaveman]

As usual, I think gear nailed it.

Interesting how 3 and 5 are both really good, while 4 is rejected.

I wonder how many times I have inadvertently dropped a large portion of a run at that temp. Guess rounded edges would be the tell tale, but I use a healthy amount of tin so might be getting a little different results.

I used to try to get all the boolits frosty, prob between 5 and 6 on the scale. Realized I was getting a lot of undersized boolits so now I run the mold til they get frosty, then back the furnace down a few clicks and let the mold air cool for a minute or so.

This has been dropping shiny, sharp, full diameter boolits. I think it would be 3 on the scale.

I may even have to remove some beagling I added since I have gotten better at finding this temp.

[milrifle]

Gear,

I really appreciate you taking the time to write out that response. Thank you very much.

[1Shirt]

Nice post gear. Like MtGun, I run as close as possible to your #5. A little frosting on the nose is fine. Got over a fascination for shiney objects when I was a kid.
1Shirt!

[Shiloh]

I shoot mine. We're talking Gears #5 or slightly higher. Mildly Flawed boolit get sorted and fired as foulers or plinking. Any major flaws go back in the pot

Shiloh

[runfiverun]

springfield i'm sure uses lee 6 cav molds the most.
i generally run my aluminum in the 3 area and the steel ones at the 5 area.
i keep the alloy on the cold side once the mold is in it's zone.
cold alloy is generally in the 650-675 area to me.

[MtGun44]

I wonder where this whole "frosty is bad" thing started? IMO, a touch too hot
usually gives me superior fillout. Certainly you can start burning out tin, but I
cast a large batch and quickly so the tin burning doesn't seem to be much, if any,
problem.

Bill

[longbow]

I shoot for #5 too (no pun intended).

I find that using straight wheelweights or range scrap I generally produce slightly frosted boolits to get good fillout. A little frosting never hurt my feelings as long as the edges are sharp.

Very good observations and list Gear! I am sure many will find that useful.

Longbow

[David2011]

Great post, Gear! Worthy of stickiness IMO.

David

[runfiverun]

it's allready linked to my "something" sticky.