casting problems

[MacCoy]

A question to those who use steel block molds: how long do you heat your molds and were yoy keep them during that? top of the pot or beside of it? I kept them beside the pot and waited over 30 minutes so the lead was hot enough, molds were not because every bullet I cast were full of wrinkles and cracks at the grooves and at skirt. Then there was the filling problem, especially with the Lyman .577 mold, half of the bullets were only half or even less filled, RCBS mold did better. This do not occur with aluminium molds, or does this happen because the mold is too cold? So when molds are hot enough for casting? I also used Lee .578 mold which cast too big bullets, but RCBS .578 & Lyman .577 are too small (they slide down the barrel freely), so do they really cast larger ones when properly heated?

[Greg Ogdan, 11444]

First, lead MUST be dead soft for Minie bullets. Minimun temp is 750 fahrenheit. I just start casting. Pour the first one, let puddle solidify, count to 5, cut sprue off, empty mould and repeat. Repeat 15 times and throw all back into pot. All folowing rounds cast should be good to within +-3 Grains of median. Yes, it's a slow start, but it's simple and it works for me. Doesn't really seem to make a difference aluminum or iron mould. I usually try to run 350 to 400 per session.Tedious, but don't need to do it often. Hope this helps.

[Mike McDaniel]

The mold must be kept as hot as possible. I put mine on top of the pot when I'm not actually casting...and I try to cast as much as possible. Keep that molten lead flowing.

And yes, the first ten or so bullets have to be written off.

[R. McAuley 3014V]

CENSORED

[paul w/McGregor's 385V]

Mac,
If you are using an electric/production pot, place your mould on top while the lead is melting. Let it heat along with the lead. Using a gas fired/Coleman setup, place the mould off to the side, but where it will heat evenly as the lead is melting.

I cast at 800-850 F with pure lead. First one or two back into the pot.

Follow Richard's directions concerning the air gap.

Commercial smelters cast at temperatures of 1000 - 1100 F to remove impurities. Casting minies does not rquire that much heat. Keep it in the 800 F range.

Take care and be safe
pfb

[David Disher 12143]

I use a Bernz-o-matic propane torch to heat the mould. Takes about 3 or 4 minutes, and usually get a great casting from the first round. Before I started doing that, I would cast 15 or 20 before the mould got hot enough. Now its seldom if I have to throw the first one or two back.

Also, found that if I pour from a side angle, and when the cavity is full, I pour for an extra second or two onto the sprue hole....I found that if I was going to have a tiny cavity or air pocket at the point in the base (which creates those pesky holes), keeping hot lead on pouring in keeps the lead from hardening too fast, and the holes fill up. Prior to doing that, I would have to cast 5 bullets to get 2 good ones...the holes kept appearing...now, when I cast, I can run out 75-100 rounds, and maybe have 1 or 2 that get a hole, and thats usually because I didnt keep pouring long enough. The excess from the extra pour time just falls back in to the pot. This is just what I have found that works.

David Disher
110th OVI

[MacCoy]

Thank you for the tips. Strange that with Lee`s moulds I have never had problems with filling the mold properly, only with these iron blocks.

[Bob Maerdian]

I warm my mold and plug on a hot plate at about medium temp while the lead melts. I cast when the lead is at 750-825 degrees F. I dont have problems with cold cracks and the bullets form well. I get a good sized puddle of lead on the sprue. Let the mold cool about 10-30 seconds before cutting sprue and droppin the bullet.

Bob

[Death006]

I use a Lee electric pot, with a bottom pour spout. I'll crank the temperature control all the way to the highest setting, and set my aluminum Lee mold on top. When the lead is good and hot, I'll cast some balls. Usually my first ten or even 15 have slight wrinkles in them. Even my aluminum mold which should heat up much faster than the steel/iron Lyman molds, requires quite a bit to heat up.
I can only imagine the iron/steel molds would take much longer to get throwing good balls. Remember the first couple bullets are going to be wrinkly because the mold will take awhile to heat up. You can always re-melt the bad balls, so no use in keeping bad ones.

Good luck!

-Burke