bad batch any ideas?

[Lloyd Smale]

Ive been doing ALOT of these bullets 9s 40s and 50s. All have turned out decent. All have passed the hammer test. Now I spent most of the day doing 120 9mm hps. Cast out of the same alloy. Processed the same. Only difference was I was rotating between casting, coating in the tumbler, putting them on trays and cooking them. I cooked them all for 20 minutes just like ive done from the start. Only difference I can see is some of the bullets were warm when I put them in the tumbler. Every other batch i did sat overnight before I coated them. They werent so hot you couldn't handle them but they were warm. I got many bullets that look like the coating is flaking off. I thought it was maybe the ones that fell over sticking to the aluminum foil. But it happened even to ones I know were standing. Doing the hammer test the coating stays on the sides of the bullets when smashed but the nose where I hit with a hammer is bare on about half of them. Any ideas? Can I coat over the first coat or because its flaking its going to come off in the barrel anyway? Could I just run them through the star and lube them and shoot them. Or will the coating still gum up the barrel. Ive got about of 1000 of these. Stupid me was water dropping them in a bucket as I went and never thought to look at the first ones before continuing.

[454PB]

Any chance there was still moisture from water dropping?

[Lloyd Smale]

they were dropped out of the oven after baking the coating.

[firefly1957]

Cook them longer see if there is a change. Could they have an oil or grease on them? ( I always rinse newly cast bullets in acetone a yellow tint is added to liquid from bullets and paint adhesion seems best.)
< What is your purpose of dropping the bullets in water after baking are you trying for harder bullets? The coating should keep fouling low if properly baked even on the softest bullets i am running soft alloy from a 30-30 20" barrel at 2040 fps no leading and under 2" 100 yard groups and bullets preform very similar to jacketed bullet in water and dry books.

[Lloyd Smale]

Theres sure shouldn't have been any contaminants on them. Impossible things can happen though. Funny thing is I just did a batch of 40s the same way (other then they sat overnight and I didn't water drop) and they turned out fine. I water dropped them to see if my ar15 would shoot them any more accurately. I know it wasn't needed for leading (if I would have done it right) I basically wasted a whole day fooling around with this batch. threw them back in the scrap pot. I know I probably could have shot them or at least tried but I just don't like things that aren't right.

Cook them longer see if there is a change. Could they have an oil or grease on them? ( I always rinse newly cast bullets in acetone a yellow tint is added to liquid from bullets and paint adhesion seems best.)
< What is your purpose of dropping the bullets in water after baking are you trying for harder bullets? The coating should keep fouling low if properly baked even on the softest bullets i am running soft alloy from a 30-30 20" barrel at 2040 fps no leading and under 2" 100 yard groups and bullets preform very similar to jacketed bullet in water and dry books.

[Walter Laich]

I would have put them back in the pot, too.
Don't think of it as wasting a day--it's experimentation and some don't end well

[Lloyd Smale]

yup I learned a lesson. While I was doing it I asked myself why I was bothering for the 9mm anyway. conventionaly lubed ones are eaiser to make in quanity and never gave me a problem. Think ill stick to this just for lower production big bore stuff.

[noisewaterphd]

They may have been contaminated.

But, perhaps is possible you coated them quickly enough that they were still undergoing a bit of "outgassing" (contaminants in the alloy surfacing)?

I genuinely have no idea, just a thought.

Almost exactly the same thing happened to me once. I coated real soon after casting, and I'm pretty certain they had to be clean.

I still am not sure what happened, but it has never happened again.

Like others suggested above, I just through the batch back in the pot.

[Lloyd Smale]

do you guys think it might be possible somehow that the lead is giving off some kind of fumes while its still warm right out of the pot that effects bonding. Maybe after sitting overnight its all gone???

Cook them longer see if there is a change. Could they have an oil or grease on them? ( I always rinse newly cast bullets in acetone a yellow tint is added to liquid from bullets and paint adhesion seems best.)
< What is your purpose of dropping the bullets in water after baking are you trying for harder bullets? The coating should keep fouling low if properly baked even on the softest bullets i am running soft alloy from a 30-30 20" barrel at 2040 fps no leading and under 2" 100 yard groups and bullets preform very similar to jacketed bullet in water and dry books.

[dverna]

I would have put them through the lubri-sizer or given them a coat of BLL and shot them. No point wasting the time spent casting them.

I doubt there is "off gassing" of the alloy but that is just an opinion.

[Lloyd Smale]

I kind of tried that. I ran a few though the star but being they were black its just to hard to see with these old eyes if the lube grove is full of lube. Then I thought that if its was going to flake off some lube sure wouldn't stop it. sure wasn't the first time ive dumped a couple batches back into the pot.

[RogerDat]

Generally "Do Overs" are a good part of casting. Nothing lost but a little pouring time, usually with the casters gaining wisdom about what don't work.

I don't know about outgassing but we all know the alloys go through some changes that impact hardness after being poured, and that those changes are more rapid in the short term and then the rate of hardness change tapers off. It might be possible that some substance such as trace of bees wax used as flux might be in the process of flowing to the surface and dissipating, and that over night that process finishes so that a better bond is achieved. Don't think this would be as likely for a bottom pour as it would for ladle casting. I have had slotted spoons get little wet stain lines from wax, no reason a ladle couldn't get some too.

Guess if one wanted to run a test one could cast a few and let them sit over night before coating and baking then cast some more from the same pot and PC right away.