Trouble casting lyman .458 360 HP's!

[koger]

I am not knew to casting, 30 year veteran at it. I am having about a 55% rejection rate, due to not filling out the base of the bullet. The mold is hot, am putting in an extra amount of lead pooling up on the sprue, no rhyme or reason. The alloy I am using is half wheelweights/half pure lead. Never had this kind of problem when casting pistol slugs that were HP's! All replies welcome!

[Larry Gibson]

Add 2 % tin to the WWs before mixing with lead. Alloy temp should be 710 to 715 +/-. If bottom pour open spout adjustment to max. If ladle use Lyman technique as per their manuals.

[475AR]

I am not knew to casting, 30 year veteran at it. I am having about a 55% rejection rate, due to not filling out the base of the bullet. The mold is hot, am putting in an extra amount of lead pooling up on the sprue, no rhyme or reason. The alloy I am using is half wheelweights/half pure lead. Never had this kind of problem when casting pistol slugs that were HP's! All replies welcome!
How hot is your pot? I find out that if I run my pot between 725-800 degrees, depending on lead mix, more pure lead the hotter I find I have to go to get good fill out and if I run tin in the mix I tend to go lower temp. If I am casting and hi-tek coating the bullets I will run it hot enough to get frosty bullets as I think the frosty bullets give the coating more to stick to.

[MT Chambers]

Add tin lots of it, cast hot, cast fast, and look the world right in the eye.

[Tatume]

Are your bullets frosty? If not, increase temperature and speed of casting until they are. I'll bet they fill out then. Frosty bullets are good bullets.

[Dusty Bannister]

Perhaps you have a venting issue or are not pouring the alloy directly down the center of the sprue hole and bridging occurs? Once the air is trapped, no amount of sprue puddle will clear it out.

[dh2]

like outer are saying I have noticed the HP mold a lot pickier about getting warmed up and I add more tin and run my pot at max

[Tripplebeards]

I casted up about 30 pounds of devastators the last couple days. I had my Lee 4/20 pot adjusted at 8. I normally don't run that hot. I rested my mold on top of the pot from the moment I turned it on. I also heat the pin on my camp stove for about 30 seconds. I had to wait a good 5-8 seconds of the extra pb rolling on top of my Sprue plate to harden. I make sure I'm titling back and forth to eliminate any air pockets and proper fill out. Never had one base fail to fill out but did have a couple of bubbles in my HP area. Strangely enough they all weighed within 3 grains of each other even with the bubble holes.

Sounds like you need your lead and mold hotter.