The Firing Line Forums - View Single Post - Cast bullets sticking in a well smoked mold

Mauser Rat · March 20, 2011, 09:43 PM

Thanks for all of the information guys. It was a lucky day when I found this forum. It's rare to be able to access so much experience in one place. And you even come at a good price!

I cast another 100 last night with some Rotometal H-ball just to check if anything had changed or it was something in the pot. Bullets stuck from the start. No difference. If anything, I had a few drop by themselves after about 80 or so casts.

I melt the Lee Pro 4 pot at max temp which Lee says is maybe 900 deg F. When everything has melted and I get the right "feel/viscosity" when stirring the pot I reduce the temp to between 650 and 700 on the dial so I get no frosting or wrinkled stuff coming out of the mold. I cheaped out at the cost of all the new equipment and did not buy a thermometer which might be the next purchase. I flux periodically with Frankford solid flux.

I smoked the molds with wooden matches having heard of the problem with candle wax. Had read not to touch the molds themselves so no contact with any of the aluminum. And I tried hitting the bolt with no real luck.

I usually wait maybe 5+ seconds till the sprue puddle solidifies and then knock on the sprue plate to shear the base of the casting. I wait a second or two more while I put the sprue waste back in the pot and then open the mold.

I have resorted to using a pair of needle nose pliers to free the bullets. Very careful to put one arm of the pliers on the generous meplat of these RNFP loads and one on the free half of the base and carefully rotate the casting away from the mold at a right angle to the face of the mold. No visible scarring of the bullet even under a magnifying glass.

I will try cleaning the mold as suggested to get all the smoking off. I have access to a stereo microscope that I can examine the faces of the mold with looking for those burrs. Thanks for the info on using a cast bullet and tapping a handle in it to use it to "open" the mold a little. I have some Japanese wet stones for sharpening shop tools that I can flatten very smooth and maybe work the faces of the molds if I need to.

Thanks again for all of the info and let me know if I can return the favor in any way. I'll let you know how it works out.

March 20, 2011, 09:43 PM	#11
Mauser Rat Member Join Date: January 3, 2008 Location: Alaska and parts North Posts: 74	Thanks for all of the information guys. It was a lucky day when I found this forum. It's rare to be able to access so much experience in one place. And you even come at a good price! I cast another 100 last night with some Rotometal H-ball just to check if anything had changed or it was something in the pot. Bullets stuck from the start. No difference. If anything, I had a few drop by themselves after about 80 or so casts. I melt the Lee Pro 4 pot at max temp which Lee says is maybe 900 deg F. When everything has melted and I get the right "feel/viscosity" when stirring the pot I reduce the temp to between 650 and 700 on the dial so I get no frosting or wrinkled stuff coming out of the mold. I cheaped out at the cost of all the new equipment and did not buy a thermometer which might be the next purchase. I flux periodically with Frankford solid flux. I smoked the molds with wooden matches having heard of the problem with candle wax. Had read not to touch the molds themselves so no contact with any of the aluminum. And I tried hitting the bolt with no real luck. I usually wait maybe 5+ seconds till the sprue puddle solidifies and then knock on the sprue plate to shear the base of the casting. I wait a second or two more while I put the sprue waste back in the pot and then open the mold. I have resorted to using a pair of needle nose pliers to free the bullets. Very careful to put one arm of the pliers on the generous meplat of these RNFP loads and one on the free half of the base and carefully rotate the casting away from the mold at a right angle to the face of the mold. No visible scarring of the bullet even under a magnifying glass. I will try cleaning the mold as suggested to get all the smoking off. I have access to a stereo microscope that I can examine the faces of the mold with looking for those burrs. Thanks for the info on using a cast bullet and tapping a handle in it to use it to "open" the mold a little. I have some Japanese wet stones for sharpening shop tools that I can flatten very smooth and maybe work the faces of the molds if I need to. Thanks again for all of the info and let me know if I can return the favor in any way. I'll let you know how it works out.