yes, ANOTHER stupid casting question!

[sergeant69]

ok, a too cool mold causes wrinkles, i get it. a too hot mold causes frosting. got it. but so what? wrinkles obviously cause a host of problems. but frosting? is it just an appearance thing or are the rds. too brittle or.............?? used to cast tons of 38/357 back in the dark ages of the 70's and remelted the wrinkled ones but loaded the frostys and never noticed any diff. in accuracy. course we weren't shooting competetion (rabbits don't count). so.........whats the deal? thanks

[HeavyMetal]

Never had an issue with frosted boolits but most of my stuff is pistol.

Shoot'em and be happy! Now wrinkled boolits? This means the mold was to cold and if ya got wrinkles ya got poor fill out to boot if ya looks hard enough!

Keep the frosted ones re melt the wrinkled ones and life is good!

[shotman]

frosty is good makes you think of the cool days of fall it also helps hold the TL if you use it

[RobS]

Yes...........cool mold/alloy temp creates a bullet that will not fill out properly and rounded edges and wrinkles occur. The casting temp of the mold becomes too hot then there is the possibility of frosting as we know it as. Certain alloys such as those that involve tin help give an alloy better flow or less resistance so a cooler casting temp can be utilized and the alloy will have good mold fill out.

Straight WW has very little tin in it and casters who are not use to casing straight often set their pots up for 700 degrees or a bit less and try to have a go at it like they may have before with their tin alloys. The common experience is bullets that have the classic fill out problems I was talking about above. Some individuals like nice shinny and well filled out bullets...............for me it is not about the shinny part has I cast straight WW for most of my casting needs and for proper fill out I have to cast hot with aluminum molds in particular and there is frosting. Does this matter to me........not at all............does it affect accuracy.............not with the amount of frosting I have which is just a bit (a slight dulling appearance). I have seen bullets that have heavy frosting in them to the point that you can actually feel it (rough) if you run your finger along a larger surface area such as the nose of the bullet. I haven't shot any that badly frosted so I can't comment on the accuracy. Another note, those that lube with alox tumble lube have stated that the frosting allows a surface that the lube adheres to better.

It really comes down to a personal thing.

[Buckshot]

.............The only time frosting is a problem is if it's localized and will generally indicate a sunken spot. Frosted all over is generally not a problem.

.............Buckshot

[lwknight]

Frosty surface just means that you got enough tin and the molds are up to temperature.
I use it as a speed indicator. When they get really frosty I just slow down and if they get really shiny , I try to speed up a bit.
I like the satin finish I get when everythng is going just right.
None of which has any effect on anything other than my eyes.

[303Guy]

Well..... not of concern to pistol shooters but I have a rifle boolit mold that with a certain alloy at certain temperatures produces a boolit that is frosted on the front half. It's to do with cooling rate of the mold and it produces a soft nose boolit with hard base. Great If I knew what the alloy was!:?: Essentially, all that was happening was the base area of the mold cooled the alloy fast enough to actually harden it. (It was a nose pour so didn't develop internal shrinkage cavities - it was fed by an even hotter sprue funnel).

[leas327]

I can tell you a fix that I stumbled upon for fixing frosty bullets. I just recently started casting and was proud of my new hobby. I threw a couple of bullets in my pocket to take to work and show off. They were kind of dull and slightly frosted. By the time I got done walking around and showing off my new boolits to everyone the constant rubbing in my pocket had shined them up enough that one of the last guys I showed thought that i made them out of silver instead of lead. So if you want to fix your frosted bullets go with my plan. Put a couple in your pocket and don't work very hard. Those will probably be the best looking boolits I will ever make and I got paid to polish them up.

[Bret4207]

They say a frosted boolit shrinks more. I haven't seen proof of that yet.

4/0 steel wool, just a quick swipe will make a frosty boolit shiny.

[kawalekm]

I've read that frosted is an indication that the too-hot bullets will be more brittle, with the possibility of breakup upon hitting the target. This might be important in a hunting situation where a fragmenting bullet might mean a lost deer.

In the real world though, I've never seen a bullet break up, and since most of my cast loads are for target shooting, it's a non-issue.

[sqlbullet]

I weighed the first few hundred I cast for my 30-06. I saw no variation in weight related to the surface effect. Frosty bullets had the same mean weight and deviation as the non-frosty ones.

I didn't measure diameter, but will add that to the drill the next time.

There is a positive correlation between lead temp, mold temp and bullet hardness all other things (cadence, etc) being equal. Using a 96/3/1 Pb/Sb/Sn alloy and casting from a Lee .401 175 gr TL six cavity mold, I found with the lead at 650°, using my standard cadence (about 800-1000 an hour from that mold), a 10 random bullet average hardness was 10.53 air cooled, and 25.88 water quenched from the mold. At 700° these jumped to 11.23 and 29.50 respectively. At 750° the numbers were 11.77 and 32.41 repectively. All samples were aged 24 hours before testing.

The bullets cast at 650° very very slightly mottled. The ones at 750° were very frosty.

Have stabilized on a lead temp of between 675° and 725°. Below or above that temp, and certain molds (Lee 200 grain 309) don't perform well. In that range, all my molds will run for hours making great bullets. They are moderately frosty.

[skeettx]

Hello All,

Frosted bullets are not a concern, but I control the heat thing by casting with two moulds. I place two ingot bars along side the pot. Fill one and set it on the bars, fill the second and set it on the bars. Pick up the first, cut the sprew, dump the bullets, re-fill the mould and put it on the bar. Pick up the second and repeat.

On many of my high use bullets, I have a matched set of moulds, so no need to sort later.
Enjoy the day
Mike

[Buckshot]

http://www.fototime.com/2D536DBA57B9FA1/standard.jpg

.........The above is not a good photo at all, sorry. It was taken awile back with an old 1 Mpx camera, that had no closeup capabilities. The story with this photo is that the slugs were cast of the same alloy, same temp, same mould (Lee 6 banger). The only difference was the mould temp.

IIRC now (no notes) the alloy was running 850º. Each eaxample was from the same cavity in the mould. The very shiny boolit on the left was poured into the mould after it had had it's base laid on a damp pad for a '3 count' after emptying. Also, after filling the SP was also laid on the same damp pad. The slug in the middle (evenly frosted) had the SP cooled on the damp pad, but was emptied and refilled without the block cooling.

The boolit on the far right cast cast without SP or block cooling. The SP was swung open and boolits dumped as soon as the sprue had setup. This was repeated several times after a few times the blocks were well heated. The sprues took some time to solidify. This boolit had a bit of a sheen to it which you can barely discern in the photo. The surface was coated with a distinct 'crystalline' structure on the surface.

Since I'd failed to keep notes I won't try to recall from memory what the differences were, other then to say there were differences in both weight and diameter. Had you been scaling slugs they'd have gone into different groups.

................Buckshot

[lwknight]

I've read that frosted is an indication that the too-hot bullets will be more brittle, with the possibility of breakup upon hitting the target. This might be important in a hunting situation where a fragmenting bullet might mean a lost deer.

In the real world though, I've never seen a bullet break up, and since most of my cast loads are for target shooting, it's a non-issue.


Slight frosting is caused by the mold being hot enough so that the alloy is not cooled instantly. Antimony crystalizes when it cools. The size of the crystals depends on the cooling rate. As antimony crystalizes it expands slightly and makes the satin looking finish. The hardness will not be affected.
It most certainly cannot cause bullets to be more brittle.

If you cast into a cold mold that cools the cast instantly you get both shiny and hardening. Also probable poor fill out.

[303Guy]

There's a lot of interesting info in this thread! Great observation, sqlbullet. Buckshot, you have advanced that observation and lwknight you have explained my observation. With shiny, no frosting to frosting there is a distinct change in hardness.

Hard shiny base and softer frosted nose section.
http://i388.photobucket.com/albums/oo327/303Guy/MVC-226F.jpg

Fired two-hardness boolit.
http://i388.photobucket.com/albums/oo327/303Guy/MVC-010F-1.jpg

The mold that produced it. (Or one like it).
http://i388.photobucket.com/albums/oo327/303Guy/MVC-742F.jpg