Casting question

[Tom]

I have a mold that casts an old style minie. The minie shoots really well in my reproduction Model 1855. The old style minies I am familiar with have the level surface at the top of the core pin and are not pointed. When casting with a core pin that has a level surface, I get a large number that are not smooth. Many minies have a “half bubble” or some kind of incongruity where the core pin and the lead meet. Out of 5 cast minies, 1 will be decent but the other 4 are returned to the melt. I still cast with this mold because the rounds shoot so well in the Model 1855. I try to keep the temperature around 850 degrees. I have tried around 775 and above 900 but nothing really changes. I hold the mold at an angle and try to pour the lead in with a ladle doing my best so that the lead doesn’t cover the hole preventing air from escaping.

Is anyone else experiencing the same thing? Do you have any suggestions? Thank you in advance.

[henrymstr]

As far as team competion is concerned blk pwdr is forgiving you prob wont see much change is number of hits. Weigh em out, 10 grns or so you will still break birds. Be more selective for individuals. 10 grns could cost u an X or a ten ring easily. My team rides me for "holy" bullets.......but most have a hard time out shooting me on sunday. Dont get me wrong, they do, but not because of my bullets. I have many other built in excuses at the ready. Good luck, them other fellas will have plenty of tech details when they read ur post.

Sent from my SM-T217S using Tapatalk

[Cannonman1]

used to struggle with my Lyman mold 575213 with the skirts not filing in completely with pure lead. I had an electric pot and ladled the lead out with a dipper.. Tried all sorts of things with little success. I ordered a 20 pound electric pot with the bottom pour feature and my first casting session went very well...Cleaned, dried and preheated the mold and plug as usual, fluxed the lead and began pouring.. By the 3rd cast, I was getting almost perfect rounds and by the 6th or so they were very nice. I am totally sold on this method.. If you are using a dipper, you might want to consider using a bottom pour pot .. I recommend the larger version as you can have a longer casting session with a constant temp. Just my 2 cents worth..
Good Luck

[bobanderson]

I cast on a camp stove converted to propane. I use a bottom pour ladle and pour into the mold straight from the top. Voids are caused by pouring too slowly and the core pin and sprue plate being too cool. I preheat my mold by laying it with the sprue plate close to the burner while I heat the lead to 700 degrees. I cast quickly so the core pin stays hot and rarely get culls, even with the first pour.
BTW - air escapes between the mold and the sprue plate, not the "pour hole."

[John Bly]

The solution to voids in the base at the end of the core pin is to keep molten lead in the sprue hole as the lead cools. The lead shrinks as it cools and if the sprue stays molten it will pull lead into the mold. If you stop the pour and allow the lead in the sprue to cool then the bullet shrinks away from the core pin. You must cast HOT and keep the sprue plate hot so that the sprue is the last to solidify. I bring the ladle and mold to vertical with the ladle in full contact with the sprue plate. I hold it in this position for several seconds to keep a column of molten lead directly over the sprue. I don't get voids this way. Try it. It takes a little practice to get it right.

[Maillemaker]

I used to cast exclusively with a bottom pour pot. I love it for its convenience, and how it avoids all problems with dross floating on top of the melt.

With the RCBS-Hodgdon, you have to hold the mold at an angle and let the lead swirl down the sprue hole or you will get visible voids. But I suspect, based on weight, that the voids might be there anyway even if you don't see them.

There are some hollow-base molds that I simply cannot get without voids / get consistent weights unless I ladle pour.

So I have come to the sad conclusion that you will get the best and most weight-consistent hollow-base bullets by ladle pour casting.

This is why I love the Moose Wilkinson, the Sharps Christmas Tree, and Round Ball - they bottom pour like a dream because there is no hollow cavity.

Steve

[B P Shooter]

I cast with a bottom pour Lee pot. I mold with a 575213OS mold. I have found that when I start having the pinhole problem in the tip of the hollowed out base, it is usually lead sticking to the air holes on the side of the mold as well as the base plug. A bronze or brass brush will usually take it off. Again, that is an issue of air flow.

I know an older member who says it's because the plug is too hot. He swears by dipping the plug into a cup of water when he gets a pinhole. I, personally, didn't care for that idea and never tried it.


What works for one does not always work for another.

[jonk]

If I bottom pour, I get poor skirt fill out.

If I ladle pour, I often get pinholes at the top of the mold plug.

Only with pure lead.

I just consider it part of the process, sort the bullets, and accept I'll get 5-10 rejects on a good day, half the batch on a bad day.

[Cannonman1]

To those who may be reading this line of comment and are planning on doing this for the first time.. or are new to the process.. Make sure you are doing this in a well ventilated zone and wear protective clothing and glove your hands and wear goggles/protective eyewear.. We all can share those "ouch" moments that are in the learning curve. A little lead splatter on unprotected skin will change your behavior in a heart beat.. just saying

[B P Shooter]

To those who may be reading this line of comment and are planning on doing this for the first time.. or are new to the process.. Make sure you are doing this in a well ventilated zone and wear protective clothing and glove your hands and wear goggles/protective eyewear.. We all can share those "ouch" moments that are in the learning curve. A little lead splatter on unprotected skin will change your behavior in a heart beat.. just saying

I will add two things to this:
A good pair of leather boots that are not lace-up.

And...well vented area doesn't mean outside in the open. Even if there's not a cloud in the sky. Water and molten lead do not mix. A speck or pindrop of water will cause an hydrogen explosion splattering molten lead everywhere.