Casting issues

[Buck98]

Sounds like everyone has given you some great advice. No need for me to repeat anything that was already said. I agree with all the replies. I just wanted to put in my 1 cents worth.

 

[Chaparral]

I appreciate everything. Trying to get some good 45/70 for my BPCR. Time for me to get out and learn to use a Soule sight.

 

[Ahall]

Mold blocks should float on there mount pins so the alignment pins can find alignment

crud and lead in the joint between the blocks and handles can bind the joint and prevent proper closure



Casting with the sprue plate against the spout increases the internal pressure on the mold when compared to casting with an air gap. I have see bullets grow whiskers out the air vents when the mold was pressed to the pot.


Lee molds are aluminum
It expands fastest than steel so if the tolerances are off the steel alignment pins can shift in use but feal solid when the molds cool.
Most Lee molds have at least one steel alignment pin


Hold the block up to a bright light and see if you see any gaps. If you see a gap you can find the high spot and shave it off

 

[nimrod]

I've cast lots of bullets with that Lee mold, but moved to a steel lyman mold.

I agree with Ahall, check to see if something is keeping the mold from closing. Or, like others have said, you may not be squeezing it shut. I like to put just enough pressure on it to make sure its closed, don't have to try to smash it.

Also, I bet running the pot on 9 is way too hot, that will cause the bullets to drop undersized as well. I have a lead thermometer, but I sort of gave up on that. I recommend try running your pot on about 6, see if the molten lead has the consistency of milk or heavy cream. The lead should be liquid, and flow easily out of your ladle or spout, but be a little on the thick side. That is usually right in that 725-775 temp range, hot enough to keep the lead liquid as it fills the mold, but not so hot that it contracts when cooled dropping undersize bullets.

I am sure we all do this differently, but I want the puddle on the sprue plate to set up within 3-4 seconds of stopping the pour, any sooner, lead and/or mold is too cold, any longer, too hot.

The aluminum molds heat up quickly, but they also become overheated quickly as well. I find that running a small fan nearby and holding the mold in front of it while while the pour sets up helps keep a consistent temp in the mold.