mold sprue plate and screws
- Thread starter castmiester
- Start date
Slughammer
Member
Just keep your 3/32 Allen key handy and when the mold is hot, loosen and retighten the set screw a few times. This will get you to the correct tightness for the hot mold.
castmiester
Active Member
Tried last time l was casting but not letting the plate fall on its own a lightly tighten. I’ll give it a whirl while it’s hot.
Huh? If the mould got hot enough to melt the piece of shot it would also be hot enough to not let the lead in the cavities harden.
I use shot behind the set screw on many moulds and it is yet to fail me.
castmiester
Active Member
the insert is brass. How long has pure lead lasted you to not fail you ?
castmiester
Active Member
Ok.. so I used #4 buck shot and cut them down to fit the hole where the allen set screw is.
My mould casted wrinkled rounded casts with melt below 700. I used the Lyman temp gauge where it recommends WW between 500 and 600... no good, too cool. Up'ed the temp, and settled at 725 ish 750 melt in the pot. Do cast Iron moulds need more heat than steel ? Or vice versa ?
Last edited:
Dusty Bannister
Well-Known Member
I do not think that the usual commercial bullet mold makers use cast iron. I believe it is Mehenite which is probably spelled wrong, but is generally called an iron mold or a steel mold. Another material is brass with aluminum also being used to make bullet molds. Aluminum tends to need more heat and often that is accomplished by casting at a faster tempo than with the other two mold materials.
castmiester
Active Member
oh my bad, the melt gets 750 ish, just saw that... I don't know what my moulds are.
castmiester
Active Member
I have old cast iron moulds RCBS and Lyman Ideal. And if you go on RCBS website they say thier moulds now are cast iron.
Dusty Bannister
Well-Known Member
I saw that when I was checking the material used in the Lyman molds as well. Leaded steel, whatever that is supposed to be. Unknown if that is just recent production or from the old Ideal days. Should not be a big deal as long as they produce good bullets.
Don’t let that Lyman dial type temp probe fool you, I have to run my melt at 900 on that thermometer to make good projectiles.
I don’t pay a whole lot of attention to heat I just keep the probe in the melt to make sure I’m staying somewhat stable, the mold will tell you when it’s at the right temp, every mold has its sweet spot, and quirks for the matter.
I have several RCBS molds and have never had an issue with the plate loosening after it was set. Is there a burr inside the sprue plate hole, or on the screw? I use a piece of glass and sandpaper to wet sand a sprue plate back flat, if ot is slightly warped, that may help.
castmiester
Active Member
I sanded the plate with 150 200 and 400 on a piece of 1/2 plywood. I used a straight edge SS ruler to check it. As I tighten the bolt down ever so slightly it begins to tip. I need friction washers. Tommarow I will go to the hardware store and see what I can find. The Lyman Ideal needs a relatively thick one from the lock washer that's on it now. The Rcbs has a beveled washer that's really thin. That one works better, than the Lyman Ideal. There's not burr on the plate hole or bolt, no.
fiver
Well-Known Member
as a guideline.
375 for steel mold temp.
400-415 for aluminum
brass gets a titch hotter than mehanite but stays heat soaked once you get it there.
just set your pot temp to 725 for the first few [20-25] pours then back it down to about 700-715.
after that it's all cadence to keep the mold in the temp zone.
3 pours is cruising.
4 is to bring the mold temp up when necessary.
if your bullets come out shiny then turn to a galvanized color as they cool your pretty much in the zone.
unless your running 4-5% tin then they don't dull off.
375 for steel mold temp.
400-415 for aluminum
brass gets a titch hotter than mehanite but stays heat soaked once you get it there.
just set your pot temp to 725 for the first few [20-25] pours then back it down to about 700-715.
after that it's all cadence to keep the mold in the temp zone.
3 pours is cruising.
4 is to bring the mold temp up when necessary.
if your bullets come out shiny then turn to a galvanized color as they cool your pretty much in the zone.
unless your running 4-5% tin then they don't dull off.
castmiester
Active Member
castmiester
Active Member
gonna guess it has to be adjusted every time you return to a new cast session ?
Winelover
North Central Arkansas
Same here. The only one I ever owned is a conical for the ROA. Back then, there weren't any custom mold makers. RCBS didn't offer anything. Always preferred iron molds.
Petrol & Powder
Well-Known Member
I have a few Lee molds and like all Lee gear, it hits a price point. Can't say I'm a fan of Lee products but their gear does have its place.
I use a Lee expander die body to hold NOE expanders and there's really no way around that if you want to use NOE expanders.
RCBS makes excellent molds but the 2 cavity limit forces me to turn to SAECO or one of the custom mold makers.
I use a Lee expander die body to hold NOE expanders and there's really no way around that if you want to use NOE expanders.
RCBS makes excellent molds but the 2 cavity limit forces me to turn to SAECO or one of the custom mold makers.