Why can't I get the wrinkles out of my bullets?

[358156 hp]

I tend to slightly over pre-heat the mould, then I let it guide me as to the pace I need to maintain. I know it sounds kind of weird describing it this way, but it's one of those "it works for me" things. It just works better for me in reverse.

When alloy cools, the sprues show separate, distinct color changes as the alloy freezes completely. Some say there are three color changes, some say five, and some must have much better eyes than mine because I've seen claims of seven or more. I see five changes with antimonial alloys, but generally only three with lead/tin only mixes. The last changes are pretty subtle. Try watching for them and see what you come up with, according to legend, when the changes stop, the alloy is solid through and through.

Or maybe we just say that to slow people down until they have counted to five .

 

[fiver]

think about it like this.
40 and 45 are dumping like 1/2 oz of hot into the mold every 2 bullets.
the rifle stuff is more like 4 bullets to add the same amount of heat.

 

[462]

I tend to slightly over pre-heat the mould, then I let it guide me as to the pace I need to maintain

Yep.

I watch for the color changes, too, rather than count to a specific number.

 

[Bret4207]

FWIW, oil in the mould tends to give me "freckles" as opposed to wrinkles which seem to come from a cool mould or some sort of surface tension in the alloy, but that's rare IME. IIRC in the past I have had spots in various moulds that gave consistent problems, as though there was one spot that had an issue letting the alloy flow in right. I've rubbed those areas with a plain old carpenters pencil and then polished the graphite away as much as I could. The problem stopped shortly after, but whether it was the pencil or the polishing I can't say. This seemed to happen on the nose on longer nosed designs more often than not for me.

 

[Winelover]

Been doing it all wrong for the last fifty years.
Nobody told me I'm suppose to count before cutting the sprue.

 

[abj]

I don't really disagree with all the fixes already offered, but speaking from exp. on my last two Lee molds I think they changed their cutting oil.
Normally on Lee molds after cleaning a new mold it took 3 heat/cool cycles, increasing the number of throws on each cycle for a total of 110/150 or so throws. 25/35/50 they would throw good bullets.
The last two molds took over 1000 bullets (6cav) in the third heat cycle for the 38/158 rf and almost 3000 bullets on the 30/155 before it cleaned up. Now around 5 throws to get to correct mold temp all is good on both molds.
I think the 30 cal mold was an oil issue. Had I done more heat/cool cycles it might have corrected itself quicker but I doubt it. I will admit I only use dawn dishwashing soap because it has always worked. On the next Lee I may have use a more aggressive cleaning method first.
Tony

 

[Rick]

Yep, same here, have never counted, watched a clock or anything else. Also have never done that heat cycling thing either. Proper cleaning and cast.

 

[Winelover]

Yep, same here, have never counted, watched a clock or anything else. Also have never done that heat cycling thing either. Proper cleaning and cast.

I know Rick uses denatured alcohol to clean his molds. I've always used just inexpensive brake cleaner. If it ain't broke, I'm not fixing it.

Never used a hot plate, originally. Though, I would use a propane torch. Key word though, is judiciously.

 

[abj]

I don't heat cycle my iron molds but when I started learning to cast with Lee Al molds, especially 6 cav. it seemed to help. I have no idea where I picked up the info. Slept a few times since then.
Tom's at Accurate, clean and cast no sweat no heat cycles.
NOE's clean, heat cycle once or twice then good to go.
The next time I wear out a Lee mold I'll send Tom some samples to copy and be done with Lee.
Tony

 

[Dusty Bannister]

This brings me to the question of style of the mold. Originally, there were only one or two cavity molds, and alignment was achieved with the V block sort of fitting. Later came the 6 cavity molds with the pins and sockets, which seemed to hold the pin position better heat cycling the mold. My one experience of not heat cycling the mold resulted in pin movement in the blocks, so that is now a standard mold prep. The new style lee single and double cavity molds now have the alignment pins and socket for alignment. I will probably continue the practice just to avoid pin movement. Perhaps this also allows off gassing of machine residue, perhaps it allows the patina to form on the mold surface. Perhaps it is not necessary at all depending upon alloy used and temperature.

 

[popper]

Perhaps the ww is SOWW? Those can have any kind of stuff in them now. Tried mixing some range scrap in? I have an old 2 hole Lee 40 TL mould, never did get good bands out of it but it shot fine anyway. I don't use any tin. Back then I didn't preheat either. Wrinkles come from cool trapped damp air expanding into the soft, cooling alloy. The hotter the mould, expansion of the (less) humid air is less so no or smaller wrinkles.

 

[RBHarter]

NOE instructions wash in Dawn blue , I put a drop on a toothbrush and rub the cavities faces and top , heat cycle to casting temp down to room temperature times 3 , pre heat and pour bullets .

I add a hot plate with an iron kettle plate and turn the mould sprue plate down when the alloy starts to sweat in the pot . I've cast 37gr 22s up to 535 gr x3 in aluminum . 32&30 cal over about 165 gr can get fiesty about mould temp . 4&5 cav 22 cals are hard to keep hot 25s can be challenging for the same reason .

The hot plate is your friend .

The above doesn't take in for oil contamination , pour methods , mould breathing , sprue hole size/shape , or oddities of alloy minutiae .

 

[358156 hp]

View attachment 26734Been doing it all wrong for the last fifty years.
Nobody told me I'm suppose to count View attachment 26735 before cutting the sprue.

Some guys are using a metronome app on their phones. or even actual metronomes. I'm not that fastidious, so I just watch the pretty colors.

 

[garrisonjoe]

Anti-seize on your molds? Well, there's a problem. That oil base lube creeps ALL over the place and most oil is not your friend in a mold.

Clean mold well. Then, if you need something for the bottom of sprue plate or alignment pins, use the thinnest possible application of 2 cycle (fuel pre-mix) oil on a just barely dampened Q-tip. That loosens any lead and lets you buff it off with a towel or even fine bronze wool. Never steel wool.

But, yes, those aluminum molds need EXTRA block temperature to get things nicely filled out.

And, add 0.5% by weight tin to the alloy that is not filling out well. That would be an ounce and a half in a 20 pound pot. "Helps fillout" and reduces frequency of wrinkles.

 

[Ian]

Tin doesn't help wrinkles from a cold mould, it lowers the surface tension (oversimplification but go with it) so the sharp corners fill out better.

Here is a study in MOULD temperature with constant, and relatively low, alloy temperature proving you don't need tin or excessive alloy temperature to get good fill out.

Tale of Three Bullets

All cast from 690⁰F straight clip-on wheelweight alloy with very little (about half a percent) tin present. Left to right: Mould too cool, mould just right, mould to hot. You don't need tin or 800-degree alloy to get perfect fillout. Just sayin'.

www.artfulbullet.com

 

[Winelover]

Very rarely do I add tin to my bullet alloy. I save it for alloys that are ratios of pure to tin.............20-1, 30-1, etc.

 

[Bret4207]

I bought a mess of tin years ago because the internet experts told me I HAD to have more tin to make those "HARDCAST" bullets that were the only hope of ever exceeding 637 fps without leading. I still have all but about 6oz left.

 

[Winelover]

I bought a mess of tin years ago because the internet experts told me I HAD to have more tin to make those "HARDCAST" bullets that were the only hope of ever exceeding 637 fps without leading. I still have all but about 6oz left.

 

[L Ross]

I like tin. 1/20, 1/25, 1/30 or 1/40 used for various black powder cartridges. I bought a fair amount for $5/lb. 35 lbs. or so. I wish I had bought 100.

 

[Foo]

OK, guys, after reading all this advice from you pros I have decided to go down the cold mold hole and experiment with that idea. The sprue does flash over on pistol mold very quickly , maybe 1-3 sec. Rifle mold is some slower. I will make sure mold is hot enough and speed up pour. It is set sort of slow at the moment. I notice the quicker it comes out of furnace, the hotter the mold stays. Thanks again everyone for the ideas and will report back who was the top troubleshooter if I get it figured out. Hopefully I can get out there Sunday. Looking forward to trying some of those rifle bullets out of the AK and SKS and I think my Jungle Enfield has small enough bore to use it also. Gotta "Git er done" cuz it is getting warm enough to spend a afternoon at the range.

OK, guys got it figured out. Mostly inexperience. I would like to say thanks for all the ideas. It was the combination of your thoughts that led me to the answer. Cold mold was answer of course but reason may surprise some I think. I have one of those little jack screw lifts to set mold on. As many know the lee 20 lb pot is hard to see the nozzle on. Well I had the mold too far away from the nozzle and lead must have been cooling off on the 1/2 to 3/4 inch drop to mold. cranked jack up so mold was 1/4 inch below nozzle and perfect bullets on the second six. Then 700 perfect bullets straight in about an hour. They would fall out and all hit the towel at the same time as soon as the mold was opened. Same with 45ACP , 40 s&w and 9mm. All 6 cavity molds from lee. Learned also as pot got lower the valve needed adjusted more open, then closed some when pot full again. Did about 1700 .40 yesterday and about 1200 9mm today. Only had about 10 to throw back into the pot due to fins (my fault for not getting mold shut). Also learned that when mold is right and you got the timing and all the casting gods are in agreement, don't quit- cast as many as you can!!!