Problem with a NOE mold.

[wesson357]

Hi,
I have some trouble with a Custom NOE aluminum 5 cavity 6.5 (.269) mold I bought used. It’s tight and shinny.

There’s a spot just over the lube grooves on the nose that has a slight depression more than 75% of the time. When it seems
to be filled good, when sizing, you can see an unsized spot, about .001’’ depression. It happen in all cavity, usually in one bottom half. Maybe only 1 on 8 bullets is perfect. Apart of that spot, all other parts of the bullets are perfectly defined

I have tried everything. The problem is less intense if the mold and alloy is on the hotter side. But, if too hot, I get the fins in the vent lines.
I cleaned and degreased the mold twice. The alloy is lyman no2.

I cast with many 2 cavity aluminum Lee molds with great success.
I don’t understand!
See the pics, sized and PC sized. Theses bullets pictured are in my "good" batch. The rejected are worst.
Do you think I could still shoot accurately with that?
Thanks
Mat

[georgerkahn]

So sorry to read your challenges with this mould! Bion, I have found it almost impossible to think of anyone more customer supportive and friendly to their needs than Mr. Nelson, owner of Night Owl Enterprises! NOE has a website at https://noebulletmolds.com/site/ with contact info, and the telephone number I have for Mr. Nelson is (801) 377-7289.
I am NOT even slightly "smart" re aluminum moulds (I use mostly brass now) -- but, with "fins" it may in fact be do to warpage from excessive/uneven heat applied to (empty) mould by prior owner? (Perhaps reason for his or her sale?)
Again -- I know I'd hesitate not a milli-second in contacting Mr. Nelson!
BEST wishes!
geo

[JonB_in_Glencoe]

Shrunken bullet syndrome.

Dan at Mountain Molds talks about SBS with large cavity boolits. While he makes many good points to consider, I have found that when I am casting long skinny boolits (mostly heavy 30 cal), the problem seems to be is inconsistent temperature throughout the mold. It's cooling off on the outsides at a faster rate then the inside. When I start getting SBS, I take a break and put the mold in my hot plate oven for a while, so the mold temperature will equalize.

https://mountainmolds.com/shrunken-bullet-syndrome/

[wesson357]

Interesting article! I may try casting only with the first and last cavity to see if that could change anything. Very annoying, and a lot of time lost.

[gwpercle]

Send these photo's and info to Al at NOE ...if anyone has seen this problem and knows how to fix it , Al Nelson would be the man . He may be busy but he will help you , Customer Service is Al's middle name ... it's why I will only buy NOE moulds now ... Al has come to my rescue every time ... and that is worth a lot to me .
Gary

[Oily]

Just for a test why not smoke 1 cavity lightly with a lighter and see if anything changes.

[wesson357]

I'd smoked the cavities with paper matchs.

[Dieselhorses]

What is the weight of your bullets?

[44Blam]

I have a mold that casts long 30 caliber boolits and I get voids like that until it is REALLY hot. As long as I keep the mold and the alloy hot, it casts good boolits. Too cool and I get voids. I throw anything that isn't completely filled out back because I would imagine they fly funny...

[BK7saum]

One problem i have had is too cool of a mold and a small, quickly freezing sprue (Even 4-6 seconds liquid wasn't enough on some molds) If the sprue doesn't stay liquid long enough for the boolit to cool and draw alloy from, the driving bands will be rounded and you will have the shrunken areas on your boolits.

Next time, pout a generous sprue, sometimes to the point of letting alloy run off the sprue plate. That may help with your problem.

[charlie b]

Shrunken bullet syndrome.

Dan at Mountain Molds talks about SBS with large cavity boolits. While he makes many good points to consider, I have found that when I am casting long skinny boolits (mostly heavy 30 cal), the problem seems to be is inconsistent temperature throughout the mold. It's cooling off on the outsides at a faster rate then the inside. When I start getting SBS, I take a break and put the mold in my hot plate oven for a while, so the mold temperature will equalize.

https://mountainmolds.com/shrunken-bullet-syndrome/

I had the same problem with long, skinny bullets. Mine were the Acc 31-210E mold (double cavity). I finally decided to try to figure out the problem. Turns out the bottom of my mold was retaining too much heat. If I let the cavity cool too much then the drive bands didn't fill out. So, I took some 'drastic' action.

I put a small stack of folded paper towel in a pan and put a layer of water in there. The paper towel stack is higher than the level of water. Heat up my mold(s) on a hot plate (setting of hot plate was established by trial and error). The mold starts out a bit warmer than needed. I pour the first bullets and count how long it takes for the sprue to solidify. If 6 sec or less that is the temp I want to stay at. I then put the bottom of the mold on the wet towel for a count of 3, then dump the bullets and repeat. As I cast I keep track of the sprue solidify time. If longer than 6 sec then after touching the bottom of the mold to the wet towel I flip it over and touch the sprue plate to the towel for 1 or 2 sec. Then keep going.

I watch the bullets and if the nose 'wrinkles' then it is getting too cold so I decrease the time I put the bottom on the towel.

I continue in this fashion and my bullets come out very consistent with fully filled out drive bands and no wrinkles on the nose portion. Very few bullets are rejected due to surface flaws as long as I maintain the mold temp in the process above.

FWIW, these times also depend on how fast you cast bullets. I never cast with more than one mold at a time so I can concentrated on keeping the right mold temp.

[wesson357]

What is the weight of your bullets?

145gr

[wesson357]

Just an update.
I've shot some of these less than perfect powder coated bullets yesterday in my swedish mauser and carcano.
Got 1.5'' 2'' groups at 100y with (scoped M38 rifle) and 4'' group with the carcano.
I'm quite surprised! I would guess the bullet get swage correctly in the rifling ???
Anyway, I'll try casting with a thermometer in the mold and pot the next time...

[dverna]

1.5-2 inch groups is not too shabby!!!

[JonB_in_Glencoe]

You must be getting a good square launch (as opposed to a cocked/crooked launch), to have stability out to 100 yds. Cocked launch would be a concern if the shrunken area is near the part of the ogive that first engages with the rifling. I would expect you'll see a flier once in a while, if that is the case...maybe even a keyhole.

[farmbif]

2" group, with carcano, that's pretty good. makes me wonder what size groups lee Harvey Oswald was getting with his mail order gun.

[wesson357]

2'' is with the scoped swedish mauser.
With the carcano TS, I get +- 4'' at 100y with the iron sight.

[Mitch]

wesson357 you did not say it you were useing bottom pour or ladle casting these bullets.I have much better resaults ladle casting long bullets.I basicaly pressure cast with a ledel. I use either a old lyman or a new rcbs ladle.the rcbs holds quite a bit more lead than the lyman.I get more consistant weight with the ladle.You say this is a nice sihney used mold.ai do nto see any signs of dirt or crap in the pics.I dont think cleaning will do anything but take the patiena off the mold.give it a few more sessions the mold may cast better each time you cast with it.Hope this helps a bit i htuink you just have a mold that is a bit harder ti get going than others.

[wesson357]

I finally solved the problem!
I got a temperature probe and drilled my mold. I'm sure my problem was a mold too cold.
It took way longer than I think to get the mold to 400 on my hot plate.
Alloy at 700-725. I got near perfect bullets right away. 9/10, good bullets.
Thanks for you help!

[Vlad_III]

Try to fill the cavities through one. So that the air through the ventilation ducts has somewhere to go.