Magma master pot

[Pistolero]

Assuming that heating the ingots up will make a significant difference misses a crucial
part of the thermodynamics of the issue. I don't know the correct numbers for lead, but
I do know them for water and the principle is identical. Changing the temperature of a
solid is called "sensible heat", and the heat necessary to melt a solid is the heat of phase
change. Phase change takes far, far more energy than sensible heat.

For water, each degree increase in the temperature of a pound of water takes one BTU.
So increase the temp by 200 deg takes 200 BTUs. But increase the temp of a pound of
solid water by one degree from 32 to 33F takes 1000 BTUs per pound. That is the
heat of phase change.
So, while heating your ingots up will help mitigate the pot temp drop a bit, expecting
a 200F increase in ingot temp to correct for a 200F drop in pot temp is way off. The
energy to change the phase (melt) is far more than the energy to change temp in the same
phase.

A premelter will be a good solution, far more effective than preheating ingots
because you will be adding liquid. Even if the added liquid is a good bit cooler than the
pot, the change in temp with a cool liquid rather than a hot solid will be far more quickly
accomplished, takes far less energy.

Jbullets smooth the bbl. As to front sight sharp vs target sharp, go for front sight every
time. A set of very weak reading glasses, like about 0.5 diopter may well be all she
needs to see the front sight sharp and minimize the target blur. I actually had some
special shooting glasses for pistol made (online, cheap as a test), 0.5 diopter to sharpen
the front sight up.

Bill

 

[Brad]

Odd you mention phase change Bill, I was just explaining earlier to my wife that getting to melt temp was faster than getting thru melt temp because of energy required for phase change.
That said any extra help in getting back to temp helps. If we can get back to temp in 3 min instead of 5 we are better off as we may be able to keep up with lead use from casting.

 

[Brad]

I counted them up, got right at 500 of these 158 swc. That works out to 11.25 pounds of lead. Figuring for sprue call it a total of 14 pounds out of the pot.
In my RCBS that means lead level is low enough to make a full ladle hard to achieve.
Think about it for a second, is pot contains more lead AFTER I cast these bullets than the RCBS would hold BEFORE casting.

 

[Rick]

Was it a less messy casting session than in the past?

 

[Brad]

On the whole, yes it was. The mould fits over the pot so much better and when pouring the rear of the ladle is over the pot, not the bench.

 

[KeithB]

Modern HVAC systems wouldn't work if there was no latent heat of solidification/vaporization.

For the visually oriented among us here is a simple graph that illustrates the relationship between the energy contained in water and the temperature of the water as it undergoes phase changes. Lead acts the very same, just at different temperatures.

 

[freebullet]

I would have drained it through a 9mm or 30pb mold on the first run out of spite for such a magnificent contraption. 500? Couple k short, Brad.

 

[Ian]

Same principle as spraying orange trees with water to keep the fruit from freezing.

Brad, have you tried the bottom pour or did you just go straight for the ladle?

 

[Brad]

Straight to the ladle. I may try bottom pour at some point.

 

[Rick]

Did you get the dual orifice? If not and you plan on any bottom pouring it's a must have.

 

[Brad]

Single orifice only

 

[fiver]

dual is the way to go.
the 2 spouts work on odd numbered cavity's too once you get the hang of it, but not so well on a single cav. mold.
the 2 spout is just a single hole in the center of a trough with 2 outlets.

 

[Brad]

Are the orifices easily changed out? I assume from the bottom of the pot when cold.

 

[Rick]

Cold is good.

Yep, two cap screws with an allen wrench, Quite simple. Just look under your pot.

 

[fiver]

yeah 2 Allen head screws. [super simple]
I have swapped them when the pot was melted and full.

 

[Rick]

I have swapped them when the pot was melted and full.

Yeah so have I but like I said . . . Cold is good.

 

[waco]

Very nice Brad. That pot looks like a winner for sure. I really have not seen one until I watched a video that Creeker posted some time ago. The dual spouts was a trip to me! I used Lee pots for the first 16-17 years and then my wife bought me an RCBS a year or two ago. It's worlds better IMO.

That beast you got looks to be worlds ahead of the RCBS. For my needs though, to be quite honest, the RCBS works just fine.

 

[Brad]

I have a Lee 20 dipper, an RCBS I got in 91 from Khornet when I finished RP school, and now this bad boy.
The two 20s can serve well for unique alloys of low usage while the Magma handles the work load for general purpose alloy.

This thing is a tank. Shipping weight was just over 33 pounds. The top lip and bottom are welded to the side walls of the pot.

I am impressed with the quality.

 

[fiver]

they are meant to be run hard day after day.

 

[Rick]

The two 20s can serve well for unique alloys of low usage while the Magma handles the work load for general purpose alloy.

That's the same as I do, much less used soft alloy (about 8 BHN) in the RCBS and most used alloy (about 12 BHN air cooled) in the Magma. Life is good!