View Full Version : 9mm Bevel Base problem, any suggestions?

11-29-2012, 06:59 PM
I have been having a go with my NOE hollow point 9mm bevel base and have encountered a problem. The boolits stick to the mold and when the pins pull it out the side of the base where the lube goes breaks off. The pins slant the boolit and that's where the breakage is occuring. Am I not letting it cool enough, running a too hot mold? I'm going to guess maybe my lead is too soft? When I cut the sprew I do hear some powder of the lead fall like little rocks. I have no idea what I am doing wrong here and would greatly appreciate any help. Would adding some tin help? Or is that only for the boolits to fill out really good? Newb caster here!



I'll Make Mine
11-29-2012, 08:27 PM
A photo of the failed/damaged boolits might be helpful. One way to check if you're cutting too soon and/or running the mold too hot (the latter leads to the former) is to wait until the sprue has completely solidified -- much longer than you've been doing -- before cutting the sprue. You might need to use a wood dowel or soft mallet on the sprue plate extension if you let the lead get completely hard -- but that will eliminate cutting and opening the mold too soon as a cause of your problem.

The other immediate question is what alloy you're casting -- that is, where did it come from? If you're smelting wheel weights and running hot, you could have enough zinc melted in your pot to separate as the boolit cools; that might explain the "powder of lead" falling when you cut the sprue; I've never seen lead powder as you describe (though I haven't cast a huge number of bullets yet, I'd done quite a lot of soldering over the years).

11-29-2012, 08:48 PM
it's from the sprue tearing the base of the boolit when you open the mold.
try a little tin in the alloy and waiting another 3 count.

11-30-2012, 12:42 AM
Thanks for the replies, runfiverun i'll try some tin. I have purchased lead here and there, so to be honest, I don't really know my mixture. I think i mixed half and half, some mono type and pure lead if i'm not mistaken. Here is a picture of a freshly cast set. Pot temp was 750, I read to get it just hot enough to start frosting. So far I haven't had any boolits frost, just break apart.


11-30-2012, 09:20 AM
You need to let the boolits harden a bit longer before you crack the sprue. You're mould is TOO hot.

My best results with an RG2 (and the 9mmBB like you have) is before I pour, hold mould with sprue up, and close the mould so the pins settle as far down as possible. Pour, wait till they solidify, then cut the sprue, flip the mould upside down, then hold the mould at an angle toward the side of the mould that does NOT have the HP pins attached, and gently tap tap tap the hinge AS I crack the mould JUST enough to let the boolits fall out. I let the wt of the boolits hopping out of the cavitied swing them out and off the HP pins.

You can open the mould enough that the pins can slide on the holder, but NOT pull the boolits out of the cavities, at this point tap the hinge to get them to fall out. Try not to use the HP pins to make the boolit leave the cavity.

You need to let your boolits cool a bit more before opening.

11-30-2012, 11:21 AM
Your pot temp is rather warm, try 675F to 700F. By the looks of it your running too high of an antimony(look how shinny the boolits are). With monotype you can go 20%mono to 80%pure( +/- 5%), they are going to be rather hard and brittle as your alloy is now. That will also help them solidify faster and not break like they are now.

Open the mold like Blammer stated already, it works best for me that way also.

11-30-2012, 01:42 PM
Thanks Darrell and 40Super for the info. I will try to lower the pot temp alittle and use more pure lead. Also I will try out the trick you are talking about Darrell, thanks. I thought those pins were the best thing in the world for the boolits to not stick to the cavity. Open wide and just a couple of taps and they slide right off the pins, guess I wasn't doing that right. I have only cast with non HP pin molds with no problems except ever so slight wrinkles and boolits sticking. The very very tiny wrinkles have kinda ocd'd me and I read up too much on getting the pot hot and the mold hot. Guess it's working the opposite effect for me with the HP's. I will give it another shot! Thanks for your guys help. Really appreciated.