Casting Temp

[ian45662]

For those who are using BACO moulds…… Have you ever tried casting at 670-680 degrees?

[Clarence]

Ian,

Not specific to BACO moulds, but I've found it difficult to get full fill-out and consistent weights below ~750-775 degrees with 40 or 45 caliber moulds because the sprues solidify too quickly. With most moulds, I find 775-800 degrees and plenty of lead poured over the sprue place give the most consistency. And take the time to let the sprue cool for at least 20 seconds or so to avoid the mould heating--that causes its own problems.

These moulds take extra caution and extra time to get match-quality bullets.

Nose-pour moulds are a different story. I've either had to cast faster or hotter to get good quality bullets.

Clarence

[Aviator]

Yes, but things kept getting better as I worked up to about 800 F.

Why do you ask?

[ian45662]

Well..... I was casting at 750-775. Sometimes I would get little "feathers" on the nose of the bullet where the 2 mould halves came together. To combat that I would just slow down. 20 second or so cool down after the sprue would harden. Sometimes a little longer. Still sometimes I would get those little fins or feathers. For the most part they would scrape off with my fingernail. A few weeks ago, I just started dropping the temps and quickened up my cadence. I was pleasantly supposed at what happened. Finning went away completely, and bullets are very smooth. With 20: I have been casting at 680 and waiting 5 seconds to cut the sprue and with 16:1 I have been running 670 with a 10 second cool. Bases are very sharp and bottoms are smooth. No voids or rips in the base. Here are a couple of pictures. One is a baco trapdoor bullet cast 20:1 and the other is a money bullet ( The one Steve told me to get) cast with 16:1. Pretty much all my bullets cast at these lower temps look like this. Also pictured is a small test sample I took from some Creedmoor bullets I cast at the 680 temp vs some that I cast at 750. 20:1 for both samples

[ian45662]

For what it's worth, I am using a PID controller to run my pot

[RB1Shooter]

Nice looking bullets! Great job.

[ian45662]

Honestly I was shocked at how well they filled out, How sharp the edges are, and how good they look at the lower temps. We will have to see how they shoot. I am able to case a lot more projectiles in a given amount of time than I can at the higher temps so hopefully it will work out.

[marlinman93]

I have a tough time getting good mold fill on larger/heavier bullets if I don't keep pot temp up around 800 degrees. Even worse with bases filling out well on nose pour molds if I don't keep everything pretty hot.

[Aviator]

Well, that's very interesting Ian!

May be time to revisit lower temperature.

[gunlaker]

I started experimenting with lower temperatures and got great results. It was then that I found my thermometer had broken and was reading about 100 degrees too low

I like about 775 degrees, but I change it a bit if I'm casting in below freezing temps. With nose pour bullets I go hotter and run the mold as fast as I can.

Chris.

[ian45662]

I set the pid at 740 and once the bullets are casting without wrinkles I set it at the desired temp and giver hell.

[Nuclearcricket]

Once you start to use a PID with your casting set up it makes you wonder how you got along without one. They just make it so easy to adjust your melt temp and make adjustments. It also makes things much easier to duplicate. With some molds liking different temps, its easy to keep track of what each likes and you can just dial things in for that particular mold.
Like Ian I have fund that nose pour molds like things a bit hotter and my adjustable PP mold likes things just a bit hotter yet.
Sam

[steveu834]

I have found that with the 96-2-2 alloy a temp of 700 degrees has better fill out than with a temp of 750 for my 40 cal moulds. I have not tried it yet with the 45 cal, but I suspect that it will be the same.

Cheers,
Steve

[Kurt]

The alloy mix you're using makes a difference with this.
I pressure/vibration cast and I use a low temperature with my lead/tin/antimony alloy or I get vent hairs casting over 725º. After my last Waage gave out again (#2) I went with the RCBA Easy Melt that has a PID Wayne made a review on several years back and it holds the temp very well.
My weight results are like what Ian is getting.

[ian45662]

The alloy mix you're using makes a difference with this.
I pressure/vibration cast and I use a low temperature with my lead/tin/antimony alloy or I get vent hairs casting over 725º. After my last Waage gave out again (#2) I went with the RCBA Easy Melt that has a PID Wayne made a review on several years back and it holds the temp very well.
My weight results are like what Ian is getting.

Vent hairs. That’s a really good name for them. I built the PID that I am using. I have 6 pots ,I think, all with different alloys. I just plug in the pot with the alloy I want to use and let the PID do it’s thing. It makes a cheap Lee pot hold a very consistent temperature but they don’t hold very much alloy compared to my Waage.