Need some help with RCBS 476-400 swc mold.

[Sax.45]

Hey folks, I need some help with this mold, I'm a new caster, this is the only mold i'm having trouble with.

I tried all diferent temps on the melt and varried my casting speed,no joy. The best results i'm getting is when the melt is at 700+ degrees casting at a fast pace. Still only getting about 40 good bullets out of 100. The good ones are filled out nicely, nice flat bases and look great, the others have rounded and frosted grease grooves but nice bases.

I cleaned the mold at least 5-6 times with alcohol, dish detergent (without the hand softener),even lacquer thinner with the same results. I'm thinking it has something with a large bullet in an iron mold that i'm not used to.

Any and all help would be appreciated. Thanks. :???::???:

Sax.45

[cbrick]

the others have rounded and frosted grease grooves but nice bases.
Sax.45

Pictures would help a great deal.

Can't be much more than a guess without seeing these boolits but sounds like it could be hot spots in the mold.

You didn't say what the alloy is, is there any tin in it? How much?

Rick

[Sax.45]

cbrick, I'm kind of a dummy with computers and can't post a pic. My alloy is reclaimed range scrap 50% and 50% coww. Don't really know the tin content but I believe it should be sufficient. I add a bit more tin (lead free solder which I think is 95% tin).

What would cause hot spots in the mold. I preheat my molds on a hot plate with a metal coffee can with a notch cut in it for the handles, Kind of like a little mold oven. I'm pretty sure there is no zinc contamination when I smelted it no higher than 675-700 deg.

Thanks.

[kweidner]

Try a swirl. I get best results not pouring directly into sprue hole but on side and let it swirl in. If that doesn't work try pressure casting. When I first started this was the only way I could get great boolits. That was years ago. Yesterday I cast around 300 255k for my 44 mag only about a dozen had to go back to the pot. It's all about rhythm.

[Sax.45]

Try a swirl. I get best results not pouring directly into sprue hole but on side and let it swirl in. If that doesn't work try pressure casting. When I first started this was the only way I could get great boolits. That was years ago. Yesterday I cast around 300 255k for my 44 mag only about a dozen had to go back to the pot. It's all about rhythm.

Thanks, I'll have to try that. I do pour at a little angle. Tryed to pressure pore, Not to good at that, seems like that would take some time to master. I tried to pour at different velocity from slow to fast but didn't seem to help. I'll try the swirl method tonight.

Thanks.:-:)

[DLCTEX]

Yours may be the rare case of too hot of a mould. The frosting on the drive bands may be saying the part of the mould adjacent to the slot for the handles which is thinner is overheated. Give it a try with less preheat and see.

[smorin2]

Hi John,i sold you that mold.I had good luck with it when my pot temperature was about 650 degrees.I oiled the mold before i had stored it though it sounds like you cleaned it good.The gentleman who suggested swirling has the right idea,it's a single cavity mold on a big block and i found that pouring to the edge to allow air to escape helped alot,Steve

[shadygrady]

got any zinc send it to me for lead

[runfiverun]

a couple of things you can try here.
the first is to loosen the sprue plate just a tick.
the second is to pour a sprue that covers the plate get it hotter.

i'm thinking you have either inadequate venting or not equal heat throughtout the mold.
or a little of both at the same time.
like you are trying to exactly time how much lead is coming out of the pot and into the cavity but are starting out fast and slowing down by the end like you are afraid to spill some.
in this case you need to adjust the flow of the pot, slow it down so wide open is about half open.

[Sax.45]

kweidner, Your tip on swirling worked great, A bit adjustment on the heat of the melt, got much better results.

Thanks.

Sax.45

[Sax.45]

smorin2, Adjusting the heat worked great but I needed 700 deg. My thermometer might be a bit off.

Thanks.

Sax.45

[Sax.45]

runfiverrun, You were also correct, I loosened the sprue plate and things started to come together. So a bit of advice from all of you helped alot. Getting nice boolits now. Very few rejects.

Thanks All.Sax.45

[Sax.45]

DLCTEX, I never thought of that. I have things working pretty well now, I'll try a lower temp, Certainly can't hurt.

Thanks

Sax.45