Bullet wrinkle problem - HELP!!

[pistolfan]

Hey fellow casters, I have a slight problem with a .41 cal brass mold. I'm casting with wheel weights, bottom pour pot, 225 weight bullet, 2 cavity. One cavity produces nice filled out bullets but the 2nd cavity 7 out of 10 have a wrinkled lube band section , on just one side of the bullet. I tried turning up the heat, down the heat, fluxing more often, scrubbed out the mold real good in Hot soapy water, used a mold release spray - clean it off used soot from a match. I just can't seem to get that one cavity to produce nice bullets. Any help would be appreciated. It is a Mountain mold, I'm pleased with the quality of this mold, as good or better than my other ones. I just have to get this bug fixed. Thanks for any help, Peter

[IntrepidWizard]

Heat the mold,the pour is to cool.

[Flash]

If you preheated the mould and raised the temp of the melt, then it's most likely a venting problem. The air has to excape when the lead is poured into the cavity. Steel mould blocks have fine groves cut into their facing sides perpendicular to the cavity. How does your brass mould vent itself? The small veins might be blocked off on the cavity that has the voids in the bullet. Also, how do you keep the lead from sticking to a brass mould?

[Leftoverdj]

Boil it in soapy water for half an hour or so. It only takes a tiny trace of oil to produce the symptoms you describe and if you have a contaminated pore or tiny scratch, hand methods can't get at it. The vent suggestion is a possibility, too. Just run a scribe gently down the vent lines. It's quite possible there is a burr where the vent line ends at the cavity. Just a bare touch should remove it, and you may not even know you have done so.

[Lloyd Smale]

I havent tried a brass mountain mold but have casted with Rob Applegates brass mold. There beautiful molds and make great bullets but there a little tougher to cast with then steel or alum. Theres a fine line between to hot and to cold and you have to get the rythm right to make it work. Id have to agree with about i think your mold is to cold. heat it by dipping it in the lead till the bullets come out frosted then cast at a rythm that just keeps them slightly frosted and youll do ok.

[haroldclark]

If you get the mold hot and it still casts with wrinkles, the first thing I would do is boil the mold in soapy water like Leftover suggested.  A first attempt to clean the mold is with Brake Cleaner spray.  If that doesn't do it, then I boil it.  

What usually causes wrinkles with a hot mold is a tad bit of oil, lube or other similar contamination.  It will not burn off as one would think.  It just keeps running around inside the mold.

I use a soap mix with TSP and Spic and Span.  A tablespoon of the mix in a quart of water and boilin for 10 minutes will solve your problems.  Be sure to rinse the mold well and then set it on top of the lead pot to dry and warm up.  It will most likely wrinkle a few more bullets until it gets up to temperature.  Set the temperature of your lead pot to 750 degrees and you may have to go to 800 degrees depending on your thermostat.  

One of the other responders mentioned there is a fine line between too cool and too hot.  Once you find that area of temperature with a clean mold, you will be off and casting like a champ.

Harold Clark

[pistolfan]

I dip the mold in the pot as it's heating up, and one cavity comes out great so I don't think it's a cold mold problem. I'll try boiling it in soapy water for an half hour or so, I didn't for very long the first time I tried that. I'll run a razor down the vent lines and see if that does it. I don't think a brass mold is any more fussy than any other type. Like I said the one cavity was casting great no matter what I did with metal temp. Thanks again for all the suggestions I'll give them a try and report back. Peter

[pistolfan]

Thanks for all of the suggestions. I sprayed it down with some auto starting fluid (ether) I didn't have any brake cleaner on hand. I then boiled it for a half hour in soapy water and finally I used a Q=tip and cleaned each cavity with denatured alcohol. I smoked them with a match and it now produces two well filled out 218 gr 41 Mag bullets. If they shoot as good as the look, look out Mr. Whitetail. Thanks again for the help. Peter