Lee Loader

I started having a problem (several actually) when casting recently. Maybe from too hot of an alloy and maybe from too much pressure or both. The thing I am asking about specifically is a problem with the base on some of the bullets having "fins" or little spots of alloy sticking off. I never had them like this before. I am attaching a picture to ask for your opinion on what caused it and what I can do about it. There were a lot of good bullets cast too, the ones in the picture were the worst. Thank you.

Usually when I see that sort of thing I find the sprue plate has gotten loose enough that it's letting alloy squeeze out under it. A warped sprue plate can also cause that to happen.

Make smoke,

Whst O3W said.

Ohio3Wheels wrote:Usually when I see that sort of thing I find the sprue plate has gotten loose enough that it's letting alloy squeeze out under it. A warped sprue plate can also cause that to happen.

Make smoke,

My experience in casting is very limited to most on this site but, I immediately thought the
same as Wheels, loose or warped plate.

Funny thing is the same casting session the .358 158 grain TL SWC sprue plate was giving me fits. the sprue plate on this mold (TL230RN) seems fine, operated well and stayed tight. I had to stop using the other mold bc it was just not helpful messing with it so I kept casting with the one mold. I had seen a few tiny specs form from time to time with this bullet but these ones were bad. Once the last one on the right happened, I just called it a night and started cleaning up. I will have to clean the sprue plate and see how it goes next time. In the meantime I need to figure out what is going on with my other mold that actually seems like the sprue plate it messed up. When I tighten it all the way where I want it, it lifts up and its not flat. The sprue plate for these bullets seems really flat and flush. Just odd. I thought the force of pressure of hot liquid was backing it out a bit under the plate maybe. Have to start fresh in a few days when the weather clears I guess. Thanks for chiming in guys.

It would be great to see pictures of the top of your mould with the plate opened and closed but here are my thoughts. I am assuming Lee moulds.
1. Loose sprue plate. Once they are loose they can be tough to keep tight without adding a lock screw. Don't over tighten.
2. Galling under the spruce at the hinge. This is usually caused by no lubrication. I use beeswax but any wax works. Just don't let it get into cavities.
3. Mould block vertical mis-alignment. If one block is lower than the other or blocks don't align firmly allowing galling or on one to push them out of alignment then finning over I suppose the lower block is possible. Over tightening the handle bolt can also cause alignment problems. The obvious check is whether rings/grooves line up on bullet.
4. Wiping caused by sprue not being cooled enough. Your bullets don't look frosted so this would be likely a really hot mould. I have had this happen to me when I first started casting. I am not sure if the blocks or plate were the hotter part of the mould. I was pouring sprues that almost covered the plate.