New casts look like junk

[wlkjr]

This is the latest cast. Can't attach a video that I'm aware of.

[mehavey]

That cast looks cold -- alloy and/or mould.

- Do you have a thermometer ?

[45DUDE]

You might try putting the mold on a heat plate for an hour. I don't clean my molds or use any chemical on them and keep them in a control temperature. I cast at around 800 degrees. Like others it looks like a slow pour with the mold not hot enough. I sprayed a mold with wd 40 one time and put it up. The next time I used it the bullets looked bad. It took about 100 castings for the boolits to start to look good. I think the wd 40 soaked into the mold. Anyway that same mold is ready when I place it on my pot to heat up the lead. My lead does not smoke any unless I flux it.

[fredj338]

653 initially which is what has always worked for me. I bumped it up to about 680 but that didn't change anything.

Smaller bullets, go hotter. I cast up to 750deg with HP molds or molds that have other fill-out issue. Clean & preheat the mold & turn that pot up.

[wlkjr]

I bumped my temp up to 735 and changed to a different mold. These are not hand held molds so you can't put them on a hot plate. I do however preheat them while they on the machine with a propane torch. I finally got a good pour with a 95 grain mold. So I switched back to my 100 grain mold and heated with the torch. This time I shot the flame down into the cavity. If there was anything in the mold the torch burned it out. Finally getting a nice looking bullet. Apparently this new lead requires a substantially hotter temp. My pour rate is about a half a second to fill the mold. I modified my caster to use a pneumatic cylinder to operate the pour handle, which is operated by a joystick. I can also operate the release handle by the same method or use the handle manually. Thanks for all the tips. I certainly wouldn't have thought I would need 735 degrees to get a good bullet. Guess I'm still learning as I go. Under 700 has always worked for me before, but I guess this new batch of lead requires much hotter temps. My mixture is a kind of bastard mix, nothing specific, a mix of clean range scrap ingots, wheel weight ingots, a handful of linotype and a half a bar of 50/50 solder-tin. This strange mix has always worked out great and coats with HI_TEK to make a very nice shooting bullet.

[Conditor22]

How cold is the room your casting in?

The sprue looks like your cutting it too soon or the countersink in your sprue plate doesn't go to a sharp edge.

the picture looks like you had cool lead in the cavity before the hot lead finished filling it (this usually happens when lead slops from one cavity to another when you pouring and cools off before you pour the next cavity but this can't happen on your automatic caster. my guess is cool mold and the lead is cooling in the spouts on the caster.


Harder lead ie. 15-16 bhn melts at a lower temperature

softer lead needs a higher temperature. Pure needs over 750°

you might have to fun smaller boolits faster to keep the molds hot.

those boolits look close, maybe a few ounces of tin would help with fill out.

[mehavey]

Again the question -- WLKJR: are you running an actual thermometer ?

[wlkjr]

Again the question -- WLKJR: are you running an actual thermometer ?

I have a pid controller, so I suppose I have a thermocouple and not an actual thermometer.

[wlkjr]

My shop is 20x40 and well insulated. I keep the heater on and it stays around 66 degrees. My lead supply is housed within the shop, so it is room temperature. The sprue cutter is not sharp, kinda dull like me.

[mehavey]

I have a thermocouple and not an actual thermometer.

That works....

[Cosmic_Charlie]

Maybe add some more tin.

[MOA]

I do from 22 cal to 45 on my MC. Always seem to get better boolits around 700 up to almost 800 degrees. The smaller calibers seem to need hotter temps to fill out. It looks like your running the bevel base molds from Magma, so the composition of the iron they use may be different than other mfg molds. I have one mold for my 9.3 that was cut by NEI back in 2012 using a blank block from Magma. All the rest of my molds are either Lyman or RCBS that I had converted by Magma to run on the MC. Their blocks might need more heat also. I also use a thermometer from Roto Metals in the pot. I have one of their PID's but haven't had the chance to hook it up yet.

[Conditor22]

Are the holes in the sprue plate in the troublesome molds the same size as the ones in "good molds"?

[wlkjr]

Are the holes in the sprue plate in the troublesome molds the same size as the ones in "good molds"?

Yes. All my sprue cutters are the same size from the 95 grain up to the 233 grain. I have corrected the problem with the knowledge and help of the good folks here. I cast about 1200 of the 100 grain bullets this evening. All of them look really good and completely smooth with no voids whatsoever. Thanks to all.