50% fill out...WTH?

[tujungatoes]

Hello.[smilie=s: Long time listener, first time caller. I need some advice from the boolit masters.

I recently got my self a lee six cavity(452-255-RF) mold, and for the life of me can't get full fill out. I'm getting 2 faced boolits. One half looks great and the other half the bands are rounded and crappy lookin'. These are two sides of the same boolit.

http://i131.photobucket.com/albums/p298/tujungatoes/6AADB042-10A5-44C0-80A9-3A630F2CA713-9150-0000106BCFB60DCB_zpseea73cfa.jpg (http://s131.photobucket.com/user/tujungatoes/media/6AADB042-10A5-44C0-80A9-3A630F2CA713-9150-0000106BCFB60DCB_zpseea73cfa.jpg.html)

http://i131.photobucket.com/albums/p298/tujungatoes/485E15E4-8E0A-41CD-977C-448F78720ECE-9150-0000106BC84FF5E4_zps922a99ad.jpg (http://s131.photobucket.com/user/tujungatoes/media/485E15E4-8E0A-41CD-977C-448F78720ECE-9150-0000106BC84FF5E4_zps922a99ad.jpg.html)

I've varied my melt temp from ~600 to 800+ degrees. Pre-heated the mold, scrubbed, smoked, scrubbed, degreased, cast slow, cast fast, added tin, stirred, fluxed, and cursed. I'm about ready to start with the human sacrifices(never liked my neighbors much anyway).

All my previous casting was done a couple years ago with the same batch of COWW alloy, same 10# bottom dribbler furnace, and a lee 312-155-2R. It all went flawlessly. I even pulled out the .312 mold and poured some of those to be sure it wasn't some kind of alloy problem...nope those came out perfect. I'm confused.

suggestions? Ideas?...Ridicule?

[JonB_in_Glencoe]

The mold is too hot, you are getting shrinkage.
The 255gr is larger and more hot alloy is transfering more heat to the mold than the 312.

Try casting a little slower and with a small desk fan blowing on the mold where you dump your boolits.

Also, try to keep the alloy temp near 100º above liquidus, which is about 650º for WW alloy.
Good luck,
Jon

[Wayne Smith]

Your mold is heating unequally. Have you any idea what is keeping one side hotter than the other?

[41mag]

I had the same issues with two Lee 6 banger molds. One the same as your using and the other the 452-300RF. Both of them did almost exactly what your describing, only thing is they did it off and on and not all the time. It nearly drove me to smacking them with my big hammer on a couple of occasions.


Also, try to keep the alloy temp near 100º above liquidus, which is about 650º for WW alloy.

This is exactly what fixed mine. Hitting the mark within 650 and 657 they both throw the purttiest boolits. If I get over that they just do whatever they want. I preheat them to about 275'ish degrees as well so that might also help. I use my pot thermometer stuck down through the sprue plat to hold it straight.

Once everything is up to temp I cast nice and slow keeping asteady but unhurried pace, and things just go fine.

Hope this helps with yours.

[tujungatoes]

Jon. Thanks for the input. I'll try to go slower and keep the melt as cool as possible. We'll see if I can avoid the wrinkles.

Wayne. I have no idea at this point. It's not even consistent. Some of them run with the mold part line. Some run against it.

41mag. Glad to hear I'm not the only one. Guess I'll keep trying.

[Larry D.]

OK folks, rookie question here.
I read in a lot of posts about the rate of pouring/filling molds. That little void is gonna fill up pretty quick, then on to the next hole in the sprue plate.

How slow are we talking here?

[btroj]

It isn't as much the time between filling each cavity, it's the time between filling the mould, cutting sprue, dumping, and refilling.

Each mould has a unique tempo it wants. Cavity size and bullet weight matter as does mould material. I use a small fan blowing on mould to aid in cooling the sprue. Even with that I figure on a 5 count before cutting sprue, dumping, and refilling.

A few second slow down between pours can ale a huge difference in mould temp.

By the way, I would still shoot those bullets. At the range I use that bullet it wouldn't matter. I still prefer to prevent that issue but I don't lose sleep over it either.

[runfiverun]

I have a lyman mold that does the same thing.
one side is perfect and one is all rounded and frosty goofy looking.
strange too it's a 2 cavity 375 mold.
I should be looking to reduce the heat, tip the mold to the other side,
clean the vent lines, did the sprue plate, cleaned for oil, even done a quick polish, added some tin, and broke the edges of the cavity's.
I finally figured out I have to run the mold hot and fast.
my pot fills both cavity's at once so I am hopping along at about 6 pours a minute, and at 675-f to 690-f alloy temp.

[tujungatoes]

Ran another 30lbs today after work. Colder and slower, but SSDD:( I'm really starting to wonder if I've got an alloy issue that somehow doesn't cause problems with the 30cal. Maybe a little Zn or something. Not enough to totally F up the melt, but maybe just enough to be a pain in my a**. Might be worth buying some from rotometals just to be sure....If all else fails i guess I can take my frustrations out on it with a sledge hammer or the O/A torch.:twisted:

[338RemUltraMag]

Dont ruin the mold, honestly I will buy it from you if it comes down to that.

[runfiverun]

try the fast and hot and see what happens.
if it starts to frost keep on going to a hotter mold.
then turn down the heat on the alloy when the boolit comes from the mold all shiny and back off the speed a little, maintaining that shiny look.

[Fernando]

Pour with the plate open fast - just keep grabbing the glob of boolits with your glove and back in to the pot.
Keep an eye on band sharpness when it gets to where you want it start casting - try front to back - then
back to front.
Maybe?