Broken Boolit... Any ideas?

[queeg730]

I cast a lot of 158 gn LSWC, and powder coated them.

The casting temperature (PID controlled), was 360 Celcius, (680 Fahr).
The coating temperature (PID controlled), was 145 Celcius, (293 Fahr) ---- I realise that most folks say about 205 Celcius, (400 degrees Fahr), but I got the number from an experienced coater, and thought I would go with it... this may be a big no-no!
The time in the oven was 15 minutes
I did 2 coats of powder

After the last coat, I quenched them in water, and when I removed them from the water, I found this one in the pics.
It had simply broken in half, and the exposed parts look very crystalised. There is only this ONE in the batch which did this, but of course, now I dont know what the state of all the others would be.

The first pic is simply the two halves sitting on top of each other.
Any ideas on this, and more importantly, can I trust the others to shoot minor loads in both 38 Spl, and 357 Mag?

290354290355290356
Grateful for any thoughts!
Mike

[OS OK]

I would take a look at the hardness of that cast and several others in that batch of Pb, try to determine if this is a 'one off' rather than reflective of the entire melt. That's strange, I don't recognize that grain, it looks more like cast steel than pure antimony. Thinking you got a gob of separated Pb, Sn & Sb through the valve or if you dip and pour, you got Sb off the top of the melt?

We'll both learn from this, I've never experienced this before.

[M-Tecs]

My guess is its a result of the bullet still being too hot when you opened the mold. Reduce the alloy temp or let the bullet stay in the mold a little longer. The coarse crystalline is common with harder alloys when you crack the bullet when the alloy is still solidifying.

[queeg730]

Thanks OS...
I haven't experienced this either!

I cut one in half using a hacksaw... I expected that it would look OK, just because of the fact that I used a hacksaw.. and it did.
I haven't got a hardness tester, but using the pencil test, the first one to scratch the exposed lead was a 'H', so I thinking somewhere around 20-22 BIN (which is probably harder than I expected).
I tried another boolit in the vice, and hammered the nose to see if I could break it... no go.. it just bent a little, so I used it as a smash test dummy... smashed down OK, with no PC flaking off.

Your theory is good... I just hope that not too many are like this first broken one.

What do you think about shooting these in minor loads (38 Spl & 357 Mag)?

[queeg730]

My guess is its a result of the bullet still being too hot when you opened the mold. Reduce the alloy temp of let the bullet stay in the mold a little longer.

Makes a lot of sense...
Thanks M-Tecs

[358429]

Openinghttps://uploads.tapatalk-cdn.com/20211017/4228374fb0997a867a1b81da946cdb9d.jpg the mold too earlyhttps://uploads.tapatalk-cdn.com/20211017/1525ffa067f3c20a633ac8897e2cd5a3.jpg

[243winxb]

Results of pouring a cold alloy into a very hot mold.

Test- bring the pot temperature up slowly so the alloy just melts. Surface should look like oat meal. Lumpy. Dont flux or disturb.

With sprue plate open, fill cavities . Watch as mold heats up. I would guess the molecules will not bond together.

[Tar Heel]

What is the alloy? I wonder if you got zinc in there.

[243winxb]

" 20-22 BIN" Your "BHN" tells me there is a high % of antimony in your alloy.

"casting temperature (PID controlled), was 360 Celcius, (680 Fahr)." Temperature to low/cold . Brittle Bullets

[Tripplebeards]

I’ve had it happen when I use to quench. The boolit was WAY to hot when it was quenched and came apart. Think of volcano lava hitting the ocean.

Had it happen many, many times opening my mold to soon when casting HPs really hot at 8.5 on my lee 4/20 pot.

[dverna]

I have not cast as many as most here, but have never seen anything like that. But I do no use "mystery alloy" made from whatever I can scrounge up.

I find it interesting that only the OP and 358428 have pictures of it and they both powder coat.....any connection?

I do not buy the alloy too cold reason IF you have good fillout. I have never had good fillout with cold alloy.

Strange>>>>

[Larry Gibson]

" 20-22 BIN" Your "BHN" tells me there is a high % of antimony in your alloy.

"casting temperature (PID controlled), was 360 Celcius, (680 Fahr)." Temperature to low/cold . Brittle Bullets

That is the problem. Too much antimony and too little tin. I suggest you add 40% pure lead and then add 2-3% tin to that alloy. You will end up with a very good alloy for .357 loads.

[queeg730]

Thanks again to all those replies... a wealth of great information!

I think the consensus is that the mold was opened too early, and the crystalized metal on the harder alloy makes sense.
And quenching immediately after the oven is another good one... In future I will let them cool a little.

I never had this issue before, but that is probably because my alloy was softer, and cooler.

I have learned a great lesson here, thanks only to you folks!
My casting knowledge has improved by leaps and bounds because of this post, and I can't thank you all enough.

Mike

[Dusty Bannister]

Was the BHN reading 20-22 after quenching from powder coating and baking? And how much time passed before taking the reading. Is it possible that the castings are being dropped from several inches onto a poorly padded surface? That might start a fracture on a hot casting that has not solidified yet.

[mdi]

I'd go with too hard alloy, too much antimony and water quenching. First I'd cut the alloy with equal parts pure then air cool and PC. This should be around 14-15 BHN. Give that a try and I bet you'll get better bullets (Don't know about too quick mold opening or mold temp. The crystalization tells me the problem is from a water dropped too hard alloy)...

[OS OK]

Thanks OS...
I haven't experienced this either!

I cut one in half using a hacksaw... I expected that it would look OK, just because of the fact that I used a hacksaw.. and it did.
I haven't got a hardness tester, but using the pencil test, the first one to scratch the exposed lead was a 'H', so I thinking somewhere around 20-22 BIN (which is probably harder than I expected).
I tried another boolit in the vice, and hammered the nose to see if I could break it... no go.. it just bent a little, so I used it as a smash test dummy... smashed down OK, with no PC flaking off.

Your theory is good... I just hope that not too many are like this first broken one.

What do you think about shooting these in minor loads (38 Spl & 357 Mag)?

I would be hesitant to shoot them in a semi-automatic, I have heard of folks breaking them like this from them rolling off the bench and hitting the floor (way too hard of lead for general casting)...I shutter to think of one breaking as it goes into battery in my 1911? Not sure what the outcome would be when I set it off?

In casting, wait till the Pb on the sprue plate solidifies, then add 2 or 3 seconds to that and the cast should be cooled enough to make a drop...I use a padded piece of 1/4" plywood to drop onto...the pad is just a 'clean' folded cotton rag...

https://i.imgur.com/rxCjTM4.jpg

Then too, I drop from only a couple inches & they land softly and roll into the pan...they tend to dent against each other much less this way also.
I generally cast between 700ºƒ & 725ºƒ...all depending on the ambient temperature in the garage. Cooler air temps. will alow my spout to freeze up and I have to use a torch to un-freeze it & then I'll crank the PID 10 degrees hotter until the spout-freezing stops.

I preheat the moulds on a hot-plate to 300ºƒ ~ 350ºƒ and I get good casts much sooner starting out the session. If I want to take a break or I have to re-fill the pot, I set a filled mould back on the hot-plate & everything is 'good-to-go' just as soon as the pot is ready again.

You may find this an outstanding reference...

https://i.imgur.com/n5EzC5e.jpg

http://www.lasc.us/Fryxell_Book_Contents.htm

[queeg730]

Folks, again thanks!
I have learned a lot from this post.

1. The mold was probably opened too quickly
2. Immediately after coming out of the oven, I drop in water from a height of about 2 feet! (yes, 2 feet), so I should give the boolits a little time to cool off, and drop from inches high rather than feet
3. Furthermore, there is no padding in the water bucket.
4. Also, the pre-cast ingots are about 12-14 BHN, it seems to be the water quenching which pushes it up, so I may not even water quench at all, considering the boolit is powder coated.

Yes... lots of great lessons learned!!
Mike

[Shanghai Jack]

Zinc poisoning?

[RKJ]

I use a padded piece of 1/4" plywood to drop onto...the pad is just a 'clean' folded cotton rag...

https://i.imgur.com/rxCjTM4.jpg

OS OK I had never thought of using plywood and cloth like that before. Thank you for the idea. Queeg730, sorry for the hijack, I've learned from the discussion too. I've not had an issue with PC but I don't water cool and I tend to wait quite a while before dropping the bullets. Hope that didn't sound condescending, it wasn't meant to be.

[queeg730]

RKJ.... no problem re the hijack, and I didn't take anything as condescending...
Every single point that everyone here has made has been just excellent! We are all learning, all the time, no matter how long we have been doing this!

Mike

[OS OK]

OS OK I had never thought of using plywood and cloth like that before. Thank you for the idea. Queeg730, sorry for the hijack, I've learned from the discussion too. I've not had an issue with PC but I don't water cool and I tend to wait quite a while before dropping the bullets. Hope that didn't sound condescending, it wasn't meant to be.

In the picture I am just about ready to pick the drop ramp up and roll all the casts under it...then I'll have more room for them to roll off into the empty pan.

[mdi]

#4! I have been casting for only about 30 years and have had no need to water quench any of my cast (38/357, 44 S/44 Magnum, 9mm, 45 ACP, 45 Colt, 303 British 30-06 and 30-30)

[dverna]

#4! I have been casting for only about 30 years and have had no need to water quench any of my cast (38/357, 44 S/44 Magnum, 9mm, 45 ACP, 45 Colt, 303 British 30-06 and 30-30)

And I thought I was the only “fool” who has never water quenched.

[charlie b]

Nope, you can add me to that list too. I use the same kind of setup as OS OK. Doubled towel as a kind of ramp into box. My box has another towel in it and is a bit deeper to hold more bullets.

After powder coating I dump my bullets on a large cooking sheet with a towel on it as well.

If I want a harder bullet I just use a harder alloy. For rifles I use Lyman #2 alloy.

[oldblinddog]

I used to WD my bullets but stopped as it’s a waste of my time. I also use Lyman #2 alloy.

[JimB..]

I though that some learned member had tested water dropping followed by powder coating and found that the process of curing the finish annealed the bullet so the benefit of water dropping was lost.

Fwiw, I’ve had similar looking results when dumping an ingot mold with 6%+ Sb a little early.

[GregLaROCHE]

I can’t say this is what is causing your problem, but your casting temperature seems low.

[gwpercle]

There is such a thing as Too Hard and Too Brittle .

50+ years casting hangun boolits ... try it this way :
Alloy - 50/50 mix COWW and soft lead . Or 1 part tin / 20 parts lead ...
Or 1 part tin / 16 parts lead for heavy loads .
Cast at temperatures given in casting guide (see stickies) I like a temperature that casts them right at frosty ... a light frost is good .
Air Cool ... forget the water quenching .
If you powder coat ... air cool ...forget the water quenching .
Size trumps Hardness ... Hardness is way over rated , unneeded and unnecessary ... as are brittle boolits !
A softer boolit with a good lube or powder coat is more accurate and performs better than a rock hard boolit .
My alloy , 50/50 COWW - soft lead has a BHN of 8 , very accurate and doesn't lead when sized correctly . Slug your barrel so you know what you got .

I don't believe in water quenching ... 50 years of Air Cooling ...
Nice to Know I'm not Alone :cbpour:
Gary

[brstevns]

If they keep tearing in the same spot I would also take a good look at the mold and see if there is a rough spot or scratch on it. Causing it to tear the bullet when you open the mold.

[OS OK]

There is such a thing as Too Hard and Too Brittle .

50+ years casting hangun boolits ... try it this way :
Alloy - 50/50 mix COWW and soft lead . Or 1 part tin / 20 parts lead ...
Or 1 part tin / 16 parts lead for heavy loads .
Cast at temperatures given in casting guide (see stickies) I like a temperature that casts them right at frosty ... a light frost is good .
Air Cool ... forget the water quenching .
If you powder coat ... air cool ...forget the water quenching .
Size trumps Hardness ... Hardness is way over rated , unneeded and unnecessary ... as are brittle boolits !
A softer boolit with a good lube or powder coat is more accurate and performs better than a rock hard boolit .
My alloy , 50/50 COWW - soft lead has a BHN of 8 , very accurate and doesn't lead when sized correctly . Slug your barrel so you know what you got .

I don't believe in water quenching ... 50 years of Air Cooling ...
Nice to Know I'm not Alone :cbpour:
Gary

"Here here!" :drinks: "Well stated, all fact & no fecies!" :bigsmyl2:

[blackthorn]

Charlie b Said "My box has another towel in it and is a bit deeper to hold more bullets."

So, my question---Once there is a layer of bullets on top of that second towel---of what benefit is it?

[fredj338]

What is the alloy? I wonder if you got zinc in there.

My question too. I have never had bullets do that. I cast about 725deg, air cool, PC @ 400 & water drop out of the oven. My alloy is range scrap with a bit of clip ww. I tend to not sweat alloy for most of my handgun needs.

[Alferd Packer]

I would pay attention to fluxing the pot more and stirring the mix well.

[Ed_Shot]

Occasionally I start seeing broken boolits during a casting session. FOR ME..... its because I'm casting too fast and not giving the boolits time to properly solidify in the mold. Again, for me, a good indicator that I need to slow down is alloy smearing on the top of the mold/underside of the spru plate. Invariably, slowing down the casting pace solves the problem for me.

[Tar Heel]

At this point I would not do anything until you can identify what alloy you are using. There has been a lot of speculation, guessing, commiseration, and advice offered without first learning what the actual alloy is that is cracking apart. I suspect the alloy is the culprit and is either contaminated or way too brittle.

In the few years I have been casting, I have never seen this problem with common alloys used by bullet casters. My hardest bullets are (were) clip-on WW that were water dunked. There is no need for anything harder. If there is, then jacketed is the way to go. I have frosted bullets with too much heat and a high casting cadence but even with Lyman #2 alloy or WW, I have never seen bullets fall apart due to brittleness. I can cast pretty darn fast too.

As indicated, I believe the root cause of the matter to be your alloy.
Hope you get this resolved.

[dondiego]

Occasionally I start seeing broken boolits during a casting session. FOR ME..... its because I'm casting too fast and not giving the boolits time to properly solidify in the mold. Again, for me, a good indicator that I need to slow down is alloy smearing on the top of the mold/underside of the spru plate. Invariably, slowing down the casting pace solves the problem for me.

Same here, high antimony alloy and a hot mold opened too early. Add pure lead and tin as per Larry Gibson.

[blackthorn]

Occasionally I start seeing broken boolits during a casting session. FOR ME..... its because I'm casting too fast and not giving the boolits time to properly solidify in the mold. Again, for me, a good indicator that I need to slow down is alloy smearing on the top of the mold/underside of the spru plate. Invariably, slowing down the casting pace solves the problem for me.

I agree with this. If you are casting and dropping too fast the bullet can develop a crack without it being immediately visible. From there on the bullet can separate at anytime, but if it makes it into the chamber and is fired you will never know. It may also be the one and only bullet so effected in that casting run-----or not---

[brstevns]

If they keep tearing in the same spot I would also take a good look at the mold and see if there is a rough spot or scratch on it. Causing it to tear the bullet when you open the mold.

The only other times I had this happen was with a to hot temp with a to hard of alloy and not allowing the bullet to cool enough before dropping from the mold, Hope this is of some help.