Help me out here!

[TexasGrunt]

Brand new NOE mold. Washed it, heat cycled it three times. Gave it a light smoke, did a run of about 300 that I wasn't really happy with but they'll make good plinkers. Today I broke it out and started casting again.

Almost every bullet had these tears on the bands. I checked the mold with a cotton swab and a cotton ball. There's no burrs.

[Grmps]

this could be caused by not venting right - make sure the vent lines are clear
I would try throwing in a little more tin
if not heat the pot up a little
scrub the molds again thoroughly
Lastly if not I would polish the cylinders VERY LIGHTLY ( a bullet from ea cylinder with a screw in it, a little fine polish of toothpaste and slowly spin for 15 - 30 seconds

[David2011]

TG,

Hope you're feeling better. That looks a lot like a problem I posted a couple of months ago. Many told me my mold was cold but I knew that was not the issue. I was using alloy from a friend that I had not processed myself. Once I fluxed it with sawdust those pits disappeared. Not much to lose by trying!

David

[Larry Gibson]

Alloy?

Alloy temp?

Larry Gibson

[JWT]

Try fluxing again. Is this a brass or aluminum mold?

[Dusty Bannister]

Consider trying a different mold at a known setting that has worked in the past. Then you will have an idea if it might be the alloy or temp or mold. It does look like the bands are rounded, but no idea what your specs or mold is supposed to produce. If these actually are tears, check to be sure the blocks are not loose and flop on the handles. Ladle or bottom pour? Different day, different issues? No sense in comparing the weight as there are voids so nothing to be found there.

Maybe a quick hardness test might give some indication if the alloy is contaminated, but with newly cast and old on the shelf bullets, that may not show anything either.

[jcren]

Looks to me like a combination of opening the mold too soon (for that mold in its current state anyway) and alloy sticking slightly to the new mold. Slow the opening to see if they set better and heat cycle for patina or treat with liquid wrench dry film (great stuff btw, no build up and can't even see it on the mold, but stops sprue plate scuffing and seals micro pores in mold). Just an idea, worth exactly what it cost ya!

[Yodogsandman]

Mold and/or alloy too cold. Maybe add some tin.

[TexasGrunt]

Alloy, 50/50 wheel weights/pure with an additional 1% tin. Later during the run I went to 2% additional tin to see if it helped. It didn't.
Alloy temp 775
Aluminum mold
Mold is hot. I use a hot plate to keep the pins hot, I had some frosty boolits that had the same problem.

I've fluxed in the pot with sawdust and beeswax.

I've got no problem with my other molds, used during the same session. My Arsenal mold was pouring just fine.

Bottom pour pot. RCBS Pro-Melt.

I had the same problem with another NOE mold, it had TL grooves so it wasn't as obvious. I'll get that mold out today and see how it's running.

[trapper9260]

Try fluxing again. Is this a brass or aluminum mold?

I say fluxing also. It look like it need to be.It will help. also for the mold.need to keep it hot. I use NOE molds and I do not have that problem and I use different cals from NOE and also other makes and do not have that problem.I flux always when I cast .I use a bottom pour mainly. When I use just the pot, I flux then skim and then cast.

[EMC45]

I would run them as hot as possible until they start dropping frosty. Then back off and see how it does. I have had this issue with Lee aluminum molds and drove me a little batty to start with. I would clean them, acetone them- all the tricks and have the same results you're getting. Only until I heated that sucker up till it started dropping frosty bullet, did it "do right".

[HangFireW8]

The pic isn't real sharp. Might have a technique problem with the dropped boolits hitting the far side of the mold. This happens to me most with a sticky mold.

-HF

[mdi]

Personally, I wouldn't smoke the cavities. Smoking is just adding carbon to the mold cavities and mebbe clogging the vent lines. I'd clean and just cast until I "broke in" the mold. I haven't smoked a cavity in many years, aluminum and/or steel molds...

[Springfield]

Don't know about the "tears' but it is obvious that the bands are not filling out. It is also too shiny, just need to get that mould up to temp. 300 bullets is nothing, that mould isn't even close to being broke in yet. How long do you wait for the sprue to cool on this one?

[JonB_in_Glencoe]

I see rounded bands. that can be venting, or it can be shrinkage. Shrinkage happens when the sprue freezes before the alloy in the cavity. As the alloy in the cavity freezes, it needs to draw molten alloy from the sprue. The remedy to that is to keep the sprue plate HOT by pouring a large sprue puddle.

BUT, you said "tearing" and then a few posts down, you said "Pins".
If this is a new hollow point mold, the pins may be sticking to the boolits, so when the mold is opened, that can tear the bands. The remedy is to polish the pins (where they contact the boolit) and then season them by heat cycles and/or casting. I've owned a few NOE RG style HP molds (I still have one), and even after I polished the pins, they still take several casting sessions to break-in. Keep trying, keep casting.
Good Luck.

PS: Also, while I almost never smoke my molds, I did smoke HP pins until they were seasoned enough to no longer stick ...I also tried sprue plate lube (2 cycle oil) on the pins, it works but is risky, as you can easily get oil in the cavities and wreck that casting session, at least that happened to me more than once.

[Smoke4320]

TexasGrunt

you have enough tin with 1-2%, heating the mold with a hotplate , fluxing .. all sounds good
I have had that issue myself with a couple of NOE Aluminum molds, not all of them, not even most of them, but a couple problem children .
did the full clean , degrease, heat cycle thing ..
After driving myself almost crazy trying different things I discovered that if I did a very small run of 50 or so bullets (with no care at to how they turned out) dump then back in the pot call it a day or 1/2 day (let everything cool all the way down).. do this 3 times . the 4th time every one of them cast like a dream
maybe it a buildup of oxides/conditioning I don't know what but its worked for my problem molds so far
Its worth a shot so to speak

[John Boy]

Bottom pour pot. RCBS Pro-Melt.

Here's your issue ... Your melt is cooling with your pour and the mold is not filling completely. Notice that the GG bands are rounded and the base is rounded also
Heat the mold and the melt up to a temperature so that with a 5 second pour (nozzle in the sprue plate hole) the sprue puddle frosts in 8 - 10 seconds.

[ghh3rd]

I had a mold that I tried every once in a while that would always do that. It finally started raining good boolits when my thermometer reached 775 - 800, got frosty well filled out boolits that shrank a little when cooled but still bigger than my sizer.

Oh yeah, forgot to mention that it also requires me to push the mold up against the bottom pour so the lead is forced into the mold - else still not perfect boolits.

[stubert]

I have an NOE brass mold that will not make a good bullet until the mold hits 375 degrees. I had it drilled for a temp. probe when I oedered it. Get it up to 350 degrees, on a hotplate, then try it.

[Hickory]

I think I know what's causing your problem.
I had this happen the other day while casting.

Let me guess, when you were prepping your mold you put a little dab of lube of some sort on the sprew plate hinge pin.
Sometimes if you get a little too much it will seep over into one cavity and cause an incomplete fillout like you have in your picture.
What I do is keep casting until it goes away.