Ladle casting multi cavity moulds

S

stubbicatt

New member
OK. Here goes. I have a couple of RCBS 2 cavity moulds, and another for 180 grain 30 caliber on the way. So far they have been short, fat, bullets, and cast just fine from a bottom pour pot. The mould on the way is a longer, skinnier, bullet.

In my single cavity Saeco 32-40 mould, I ladle cast, and get really consistent bullets. This I do on advice of old timers who "know" what they are talking about. I have been told that a bottom pour pot will throw bullets of inconsistent weight and containing voids. I have never even tried the bottom pour method on this mould.

So I find myself wondering what technique to use when pouring two cavities with a ladle? On my single cavity mould, I place the nozzle of the RCBS ladle into the sprue plate hole to form a tight seal, rotate the whole assembly vertical for a count of 2, then remove the ladle to form the sprue.

How would you do this with a 2 cavity? Some of the sprue will surely go into the other sprue plate hole and cavity, thus ruining that bullet?

I do believe that I will try the bottom pour on this mould, just to see what sort of consistency I get. I may in fact place the sprue plate onto the bottom pour nozzle in attempt to duplicate the technique I use with the ladle.

Suggestions? Thanks in advance.

Regards,
Stubb.
 
Do the same you are doing with a single cavity. Fill one and then fill the other.

You should have no problem with overflow filling the second cavity. I've done this on my 4 and 6 cavity molds with no problem. Just take your time. Fill one then more your dipper to the second. After you fill the second cavity don't worry about a little overflow. It won't affect anything.
 
With the exception of one bullet design, all of my molds are 2-cav or larger and I pour with a ladle.

I don't use the 'sealed' spout method, though. I hold the mold level, and pour with the ladle about 1/2" or so above the sprue plate. As soon as the first cavity is full, I move the the next. Some alloy will be on the sprue plate, forming a partial sprue. Once the second cavity is full, I stop the pour and there's usually enough over-fill to form a decent sprue. 95% of the time, both sprues are connected and the first was still at least partially molten when the second was formed.


Where it gets tricky, is when you're casting large bullets with a small ladle. If you have to use multiple ladles to fill all of the cavities, the risk of overflow hardening in the second (or third, or fourth) cavity is higher.
But, a bigger ladle will fix that problem. When things get rough, I pull out the #1 Rowell ladle (1 lb capacity). ;)
 
I will roll them with a ladle when I use my big pot, but when using the bottom pour, I can't tell the difference in cast quality.

The longest bullet that I cast regularly is just a tad under an inch long, and the mold throws some awesome bullets with either dipper or bottom pouring.
 
I will roll them with a ladle when I use my big pot, but when using the bottom pour, I can't tell the difference in cast quality.

The longest bullet that I cast regularly is just a tad under an inch long, and the mold throws some awesome bullets with either dipper or bottom pouring.

I use three different ladles and the big 'un can fill an ingot mold with one pour.
 
Point of reference?

As a point of reference, has any of you weighed longer skinny slugs cast from a bottom pour against slugs cast from a ladle with the "sealed" method? I haven't, and I suppose I should, as if I can use the bottom pour, I would much rather do so. If they all weigh the same between the two methods of pouring, I would prefer that method for sure.

I'm using a pretty soft alloy, about 20-1 for the schuetzen bullets, as they are breach seated on occasion for best accuracy. Here lately I'm loading fixed ammo, which is an adventure seeing as the throat of my rifle has been tapered to facilitate breach seating. I am considering using my handgun alloy for my fixed ammo, which is 1 part lino to 1 part pure lead.
 
As a point of reference, has any of you weighed longer skinny slugs cast from a bottom pour against slugs cast from a ladle with the "sealed" method? I haven't, and I suppose I should, as if I can use the bottom pour, I would much rather do so. If they all weigh the same between the two methods of pouring, I would prefer that method for sure.
Click to expand...
I haven't.
But I would expect bottom-pour bullets to be more consistent, possibly only deviating in relation to the level of alloy in the pot.
 
I always weigh to get an average and to check to see if my alloy is where I want it.

I have not determined any weight difference between the 2 pour methods that are discussed here.

The only part that counts is what is below the sprue plate, and if you have a complete pour, then they are all the same volume.

I cast my bullets soft, too. If you like the bottom pour, go for it.
 
The only part that counts is what is below the sprue plate, and if you have a complete pour, then they are all the same volume.
Click to expand...

In general, I agree.

But, additional pour pressure can mean better fillout. And better fillout means heavier bullets.

It's right along the same lines as managing weight through alloy temperature. I have a few molds that aren't picky about temperature, and I can vary bullet weight by up to 6 grains, just by controlling alloy temp. Hot alloy = light bullets. Cold alloy = heavier bullets.
I can also get larger diameter, heavier bullets from molds right on the edge of overheating (due to mold block expansion), but that's not a recommended practice.
 
I can also get larger diameter, heavier bullets from molds right on the edge of overheating (due to mold block expansion), but that's not a recommended practice.
Click to expand...

I have one mold that has those traits from Accurate Molds. It casts a beautiful 0.382" diameter 260 gr bullet. I don't go quite so far as nearly overheating, but it does like it hot.

The only time I do not get fill-out is with the culls. I don't keep anything marginal, such as bottom edges not sharp or wrinkles, etc. Once I get the mold to the sweet spot temperatures wise, it is Katie bar the door and we are off and running. Not uncommon to get 2 casts per minute with the larger ones. And, best of all the weights are very consistent.

It only makes sense regarding the hot alloy vs. the cooler alloy.

I am not sure I follow the better fill out analogy, because if there is insufficient fill-out, then that is a bullet to toss.
 
You must log in or register to reply here.
Back
Top