Inconsistent weight
- Thread starter RLD4570
- Start date
Brad is right, if your using a LEE pot you may not be able to use the Rowell #2. It's a snug fit in the RCBS 22 pound pot and I think the LEE pot is smaller than that. The #2 is a two pound ladle, hold two pounds of alloy. The Rowell #1 is a one pound ladle and should be bigger than the Lyman.
The main purpose of adding tin to the alloy is that it reduces the surface tension of the alloy as it flows into the mold allowing the alloy to pick up the fine details of the cavity. Sn will also add minor hardness to lead which over 100 years ago was the main reason for adding it. The metallurgy of Sn is that starting about 750 degrees Sn looses it's ability to reduce surface tension and your losing the reason for adding it.
100 degree pot temp over full liquidus temp of the alloy is plenty hot. Different alloys with varying amounts of Sn have different full liquidus temperatures, to make things simple I do almost all of my casting with a PID controlled pot at 700 degrees. The only time I ever go any higher with the pot temp is with small bullets (22's) and large blocks and some HP molds where I'll crank it all the way up to about 720-725 degrees. Higher pot temps are not your friend, a pre-heated mold and a fast enough casting pace are.
The main purpose of adding tin to the alloy is that it reduces the surface tension of the alloy as it flows into the mold allowing the alloy to pick up the fine details of the cavity. Sn will also add minor hardness to lead which over 100 years ago was the main reason for adding it. The metallurgy of Sn is that starting about 750 degrees Sn looses it's ability to reduce surface tension and your losing the reason for adding it.
100 degree pot temp over full liquidus temp of the alloy is plenty hot. Different alloys with varying amounts of Sn have different full liquidus temperatures, to make things simple I do almost all of my casting with a PID controlled pot at 700 degrees. The only time I ever go any higher with the pot temp is with small bullets (22's) and large blocks and some HP molds where I'll crank it all the way up to about 720-725 degrees. Higher pot temps are not your friend, a pre-heated mold and a fast enough casting pace are.
Bret4207
At the casting bench in the sky. RIP Bret.
I don't think Lee ever made a pot that will take a #2 and a #1 may be pushing it. I use a #1 and cast over 1500 grs per pour. I think if a %1 will fit in the pot, it carries more than enough alloy.
Mould temp, as opposed to pot temp, is critical. I don't know if you can do it with your present set up, but try really moving your casting speed up. Don't sit there looking at the bullet or mould, just cast as fast as you can while maintaining quality. Thats how you get the mould temp up and keep it up. A bigger ladle isn't going to do much for you if you have the habit of standing there QA'ing each casting and critiquing it. Just cast and keep casting. I think you'll see some improvement pretty quickly.
Mould temp, as opposed to pot temp, is critical. I don't know if you can do it with your present set up, but try really moving your casting speed up. Don't sit there looking at the bullet or mould, just cast as fast as you can while maintaining quality. Thats how you get the mould temp up and keep it up. A bigger ladle isn't going to do much for you if you have the habit of standing there QA'ing each casting and critiquing it. Just cast and keep casting. I think you'll see some improvement pretty quickly.
RL, here is some discussion on the Rowell, the RCBS ladle pot and ladle casting. Might be of some help for you.
https://www.artfulbullet.com/index.php?threads/rcbs-easy-melt.3638/
https://www.artfulbullet.com/index.php?threads/rcbs-easy-melt.3638/
AndyTheCornbread
Member
I run my pot at about 700 - 715 and it is a bottom pour pot so I don't use a ladle anymore but like the other guys have said, uneven fill out like that is a cold mold. I keep a propane torch right by my casting bench and I preheat my mold and sprue plate with it before I start casting or if the mold gets too cold during a casting session. I use a 50/50 alloy for nearly everything and I rarely add tin to that. Just keeping the mold hot and the alloy around or just barely above 700 is usually enough to get good fill out for me with that alloy.
Martini 38-55
New Member
I'm using an RCBS 30-180SP with the gas check spud reamed to plain base, normally casts at 188 in 20-1 at 800F for my 32-30 Remington Hepburn in a Ruger #3. I use a Lyman Mag 20 pot and an RCBS ladle, check temp with the Lyman digital thermometer. I tried dropping the temp to 700 and had over a 3 gr. weight variation on acceptable looking bullets, where I normally have only about 1 gr. range on weights. Temperature on the pot is going back up. I just have to flux a little more often.
That most likely is a mold temp issue not a pot temp issue.
Here's something for new casters looking for minimal weight variation to consider, after the mold is up to a temperature that's it's starting to drop decent looking bullets do not keep the next 8-10 pours after that point. The earliest bullets out of a casting session will be the lightest bullets from that session assuming a consistent casting rhythm. While the mold may be warm enough to not drop wrinkled or incomplete bullets it is not quite yet at it's happy place.
fiver
Well-Known Member
you have to pay attention to the mold if you want consistency.
the bullets will give you visual clues as to when your in the zone you have to do the work of holding the handles the same and keeping the appearance the same throughout a run.
I have an accurate mold that will flat wear me out running it because of the attention to detail it requires.
about an hour is all I can take, but it's worth it to have about 250 bullets within .3grs of each other straight from the mold.
the bullets will give you visual clues as to when your in the zone you have to do the work of holding the handles the same and keeping the appearance the same throughout a run.
I have an accurate mold that will flat wear me out running it because of the attention to detail it requires.
about an hour is all I can take, but it's worth it to have about 250 bullets within .3grs of each other straight from the mold.
Yeah the handle is for some strange reason too long, at least for me and I did cut it down. It's heavier than the Lyman or RCBS ladle but somehow with the Rowell #2 in one hand and a four cavity brass mold in the other I just don't seem to notice the weight of the ladle.
Uncle Grinch
Active Member
There’s a lot of good info in this thread. While I’m not into competitive shooting with cast bullets, I do want to cast the best that I can with the two Lee bottom pour pots that I have. No PID to control temperature, but I do use an infrared thermometer to monitor alloy and mould temp.
Thanks for the great info guys!
Thanks for the great info guys!
