I believe the suggestion to dip an edge of the mold into the melt was to heat up the mold quickly before the start of casting. If you do this while casting I think your bullet weights will change significantly.

I ordered a graver tool today and will chase out the vent lines a little to see if this helps.

This is an entertaining thread. I think it's time that it got renamed, though= to Casting Problems Created

JS
How do you lap the mould ?.
Mike.

The typical reason for the bullets not wanting to drop out of a mould are two fold. #1 the bullet cavity was not cut dead center in the two mould block halves. #2 If lube grooves were not tapered or not being cut rounded. They would then probably have been cut square or lathe bored that way and that in itself would prevent the bullets from wanting to drop out. You can probably get away with the cavity being cut .005 thousands more on one side than the other but anymore than that will lock the one side in. Think of it as now creating a C and you can visualize what happens if going past dead center and why it is now locking the bullet in. As you know you may still be able knock the bullet out of the mould. But you still need to visualize what it will do to a once per-say perfectly round base once it's been knocked / forced out. 
In regards to dipping the front edge of the mould into the alloy when already up to temp., please go back and re-read what it was I posted in that regard. 

JLouis,

I agree with you but would add reason #3, there are small burrs left in the cavities on the mass produced molds, for whatever reason. I have several Accurate Molds and one Hoch. All of these worked very well right out of the box. 

JS

It's real difficult to cut a mould having the base real close to being perfectly round. Using lapping compound to get rid of any burrs will very quickly make everything out of round. The best way to do it is to use a wooden tooth pick to raise up the burrs. Then to carefully stone them off using a fine and flat honing stone. If you are dead set on using a lapping compound be extremely careful as you can also increase the size of bullets parting lines and completely ruin what was once a good mould.

hepburnman wrote on Apr 29^th, 2020 at 8:38pm:


That's why I get the pilot hole centered up in the drill press vise or the lathe.  Sure, there is a little wobble when I spin the bullet in the mold with the hand held drill. Let's not over complicate this job. All we are trying to do is to remove a few very small burrs and machining marks. Doing so won't change the dimensions of the cavities. I've tried, like Schuetzenmeister, to round out an out of round mold by lapping. All I ended up with was a little larger out of round bullet. Shooting out of round bullets is a whole nuther subject.

JS