help a newb. first cast

[thursdaymike]

Do I casted my first batch of bullets and right away I knew I was doing something wrong. Tried moving mold closer and farther from the spout of my lee 4-20. That didn't help. My thermometer said 750 degrees. I'm stumped. I tried adjusting flow faster and slower. Went all the way across the spectrum.

[Smoke4320]

either oil in the mold or mold is too cold .. ot taking too long between cast so mold cools off

If this is your first casting and you did not clean mold I would clean well with a toothbrush and comet. then oil pins and sprew plate lightly
heat mold very good ..it may take 20 minutes or more to completely heat mold depending on your heat source
then try again

[s mac]

I agree, looks like your mould is not hot enough, cast and dump a little quicker, don't spend so much time looking at them while casting. When they are slightly frosted thing will come together.

[toallmy]

You should have sean mine at least yours look like a bullet just a wrinkley bullet

[thursdaymike]

Okay I was afraid to overheat mold. Noe said its not designed to be over 600 degrees so that had me scared.

[thursdaymike]

I did clean mold with dawn and a brush before I used it also.

[williamwaco]

Mold too cold. Cast faster.

Sprue puddle should remain liquid for two to three seconds before hardening.


750 is fine for your alloy temp. I shoot for 600 to 700.

Mold temperature is more critical.

[thursdaymike]

Good to know the spruce puddle cooled almost instantly.

[Smoke4320]

Good to know the spruce puddle cooled almost instantly.

yes theres the answer .. mold to cold

I like to run my NOE mold hot .. sprue takes 4 to 5 seconds to cool

even then it make take a few bullets before all gets evened out and you throw mostly good bullets
every mold seems to like something just a little different

[Toymaker]

At least you got whole bullets your first time. I only got halvies.

As said above. Mold is too cold. Heat it up and cast fast.

I had a mold that had a "line" on the bullet that I couldn't get rid of. I washed it several times, rinsed with alcohol and acetone only to find it still there. Someone suggested I boil the mold block, so I did. Then rinsed it with acetone. Worked like a charm.

[thursdaymike]

Third batch and wow what a difference! Heated mold a lot more. Still had about 35% culls but due to me dropping too fast and a couple had trash between molds from preheat which created lines at seam.

[reddog81]

Congrats. It's kind of a "Eureka!" moment once you get some pretty looking bullets.
I was trying out a new mold today and was having problems until I bumped the temperature up and moved the mold closer to the pot's spout.

[paralaska]

I made lots of bad boolits until I finally got the hang of it. Best thing I did was to buy a hotplate to warm up the mold, and second best thing was to buy a lead thermometer so I could make adjustments and keep the alloy at the right temp. . . .

[Yodogsandman]

Some of your bases look rounded at the edge of the gas check shank. Try pouring a much larger sprue puddle which will keep the sprue plate hotter and probably prevent that.

[mongoose33]

Some of your bases look rounded at the edge of the gas check shank. Try pouring a much larger sprue puddle which will keep the sprue plate hotter and probably prevent that.

To add to that, you should see a dimple form in the center of the sprue as the boolit cools inside the mold. As it cools it shrinks and draws alloy from the molten puddle on top of the sprue plate. That's why you not only want the sprue plate up to temp so the puddle will stay molten for a few seconds before it freezes, but you want enough of a puddle to keep the whole thing hot. This will help fill out the base and give you good sharp edges on that base.

Someone here (can't remember who, I'd like to credit him) once said that you should think of the sprue puddle not as pouring alloy, but as pouring heat. I think that's a pretty apt description.

When I see that dimple form in the center of the sprue puddle (over each cavity), I know I've had a good pour.

[badbob454]

try a little tin , i agree needed the mold hotter and possibly some oil on mold surface 2% tin will make the mold fill better and give smoother boolits .

[thursdaymike]

Thanx for the tips. So now I have another problem. I'm using the Lyman 4500 lube sizer. Bullets are dropping .312 and I'm trying to size to .308 the top punch is deforming the bullets due to the force I'm having to use. Should I size a step between like say a .310 then the .308?

[Silverboolit]

What are you shooting them in? If a .308, you should size to .310-.311, depending on your slug size. You did slug the barrel, right?

[thursdaymike]

300 black out. I slugged barrel it measured .306

[Yodogsandman]

Thanx for the tips. So now I have another problem. I'm using the Lyman 4500 lube sizer. Bullets are dropping .312 and I'm trying to size to .308 the top punch is deforming the bullets due to the force I'm having to use. Should I size a step between like say a .310 then the .308?

That looks like you hit the edge of the top punch when the bullet nose was entering it. Do you have that specific bullets top punch?