Casting temp question


March 8, 2006, 10:59 AM
Hey all, I've got a question regarding the right casting temperature.
I'm using a lyman #2 alloy and I cant seem to find the right temp where the bullets fill out the mold completely but dont come out frosty.
The mold is a RCBS 44-250k and this past weekend, I had to keep the lead temp at about 850-865 to get crisp bullets. Problem is, at that temp frost starts to become more of a problem. Now I know that a little frost doesnt hurt anything and will wipe right off of the bullets but I would like to find that magic combination that produces frost free sharp edged bullets.
Any Ideas?

Thanks a bunch.

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March 8, 2006, 11:27 AM
It may need a little more tin, the mould may be contaminated with burnt oil or the vent lines may be clogged. Clean with a degreaser before use, use a non steel brush to clean gently. I keep my moulds in an ammo can with a dessicant to keep them from rusting so I do not oil them. Sometimes a mould will fill out if you gently tap on a wood surface before the sprue hardens. hope this helps.

March 8, 2006, 11:37 AM
I cast at about 700 degrees and they fill out fine. Like mentioned, clean the mold real good with degreaser.

When I turn the pot on, I place the first mold I'm going to cast with on top of the flat portion of the pot and let it warm up before I start casting. I often use two or three molds during a casting session, so the second mold I'm going to use will get filled with lead and then placed on top of the pot while I cast with the first one, until it gets too warm. Then I'll start with the second one while the first one cools a little bit. Then I just keep trading them around while casting.

The key is getting the mold warm enough to allow the alloy to flow within the cavity before it hardens.

Hope this helps.


March 8, 2006, 12:53 PM
+1 on looking at the mold for answers: clean, degrease, vents, etc. I cast at about 750 degrees. Larger mold blocks (especially 6 cavity H&G) work better for me and small 2 cavity blocks for big bullets seem more sensitive to temp variations.

Good shooting and be safe.

March 8, 2006, 02:35 PM
+1 on bullet size, the .44 and .45 moulds are more sensitive than the smaller bullet moulds I have.

March 8, 2006, 04:09 PM
You don't need over 750 degrees and 650 to 700 should work. Most moulds could stand the loosing of the spure cutter. This helps the bases to fill out. Most my spure plates will close simply my gravity.

Try 700 degrees and contol the mould temp by your speed of casting. IMHO frosting is a void in the bullet. If they are frosted all over they will work fine. There are however limits to this.

I've had 3 or 4 of the moulds you're using and none have cast well. They have cast good bullets but have been more difficult for me to use than the Lyman, NEI and Ballisti Cast moulds I own. Just my two. God Bless...........Creeker

March 8, 2006, 09:02 PM
Agree that low 700's should be plenty hot to do the job. I find that it takes my RCBS and Lyman moulds some amount of time to warm up and start dropping nicely filled out bullets.

Sometimes as many as 10-15 fills as fast as I can go....allowing the sprue puddle to harden over + 5 sec...before they start coming out nice.

It IS tempting to want to turn up the lead temp when they don't fill out. Be patient and keep going and you will find the lower temp to work fine and produce better bullets with less dross formation. You can still get the molds too hot if you go too quickly so slow down a bit if they start to frost. Best of luck.

March 9, 2006, 01:05 PM
Thanks All:)

March 9, 2006, 09:47 PM
If you go much over about 700F the tin comes out of solution.
You have probably messed up the alloy ratio and now need a very high temp to get the almost pure lead to flow.

Paul "Fitz" Jones
March 11, 2006, 05:00 PM
When selling my Saeco 1,000 watt lead pots designed for Saeco 4 cavity molds I set their temperature at 750 degrees to start the customers off and there are many variables from the bulletcasting room temperature, whether one or two molds are rotated and the composition of the metal alloy.

I designed my Saeco molds for common tire weights with some lino or tin added if desired for bullet beauty. I also added formulas for making Lyman #2 alloy from Scrap yard materials with the use of our newly invented Saeco Steel Lead Hardness Tester.

I also recommended ONLY ordinary candle wax for fluxing to put the tin back into solution and only dry powder should be removed from the top of the melt.

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