lube groove question

[herbie]

i noticed that the lube groves edges arent fully 90 degess. they are kind of rounded.

also the lead seems gritty.

dont see any oatmeal so i dont think its zinc, could it be something else?

[fredj338]

Make sure you flux the alloy often. This helps pull any impureties out. Very few mold designs have straight lube grooves. It's just harder to get the bullets to release.

[runfiverun]

you couldn't get the boolit from the mold with 90* angles.
i'm thinking you have rounded corners [poor fill out].
tell us more about your set-uup and the temp you are using.
your alloy etc.

[trk]

i noticed that the lube groves edges arent fully 90 degess. they are kind of rounded.

also the lead seems gritty.

dont see any oatmeal so i dont think its zinc, could it be something else?

Since the EDGES aren't sharp, the alloy isn't filling out. Could be several causes.

If the lead is gritty, it needs to be cleaned (fluxed) better.

It's generally a good idea to smelt your lead alloy in a different pot than what you use for casting. that makes it easier to keep the casting pot clean.

Suggest using a good flux (there are many) and clean the grit out of your alloy. I use a cast iron pot or a stainless pot and a $5 yard-sale turkey frier propane heater. I use borax (it's cheap) and stir with a wooden board/shaft/spoon. Stir - skim - stir - flux repeat repeat.

A little hotter will cast better - both mould and alloy. 650 should be plenty.

A little TIN added will also help the mould to fill out. A cold mould will cause fast cooling - leaving wrinkles and rounded edges.

Take notes, take pictures, get back with us.

[herbie]

dont have any pics at the moment but i am using a mixture of WW, range scrap in a lee bottom pour 20Lb melting pot and temps between 650-750. Have fluxed a few times and i notice that no matter how hot the mold got i would still get a thin layer of silver film attached to the mold body when submerged in the pot. Ill just keep fluxing i guess.

[trk]

Sometimes the fine grit is a bitch to get rid of. Again, take a pinch of borax and stir with a wooden stick.

Bottom pour is ok. You may need to increase the rate of flow. Easy to do with a ladle - just open up the hole with a drill a little - or - vary your technique - like mate the ladle and the mould and rotate both 90degrees.

If you can adjust the valve - open it up a bit.

If you have any solder add it to your mix. Most, not all, will have a percentage of tin. That will help the mould fill out.