9mm cast question

[Crownless]

I recently purchased a used Lyman 356402 2 cavity bullet mold. Its a 120 grain Truncated cone .356 dia. Appears to have very light use, if any. everything is tight. Mold sides come together properly. The problem I'm having is that its dropping bullets that are approx .363. .007 larger than spec for it.

I'm new at casting. This is my first attempt at it.

My casting material is pure wheel weights poured from a lee 4-20 pot. Bullets are not being quenched. Bullets come out looking as they should.

I'm totally stumped here. Not sure if I'm doing something wrong or if its a defective mold.

Thanks for your help.

 

[armoredman]

Not an issue. Get the Lee push through sizer, size within one day of casting. I use One Shot lube on the bullets before sizing. My favorite mould drops at .360, so I size it for both 9mm and 38, works great in both. The Lee sizer is pretty cheap, $15 or so. They come in set sizes, so if you want your bullets .356, that's the one to get.

 

[NuJudge]

Before you do anything else, check your calipers. Measure a bullet of known diameter, and you may find the extra .007" is them.

In the future, use some graphite mold spray of the sort available from several vendors. Also, use Lead alloy that does not have Antimony, as it causes bullets to grow a thou or so.

Whatever size you use, assemble a dummy cartridge and make sure it will fit in your chamber(s) before you load up a bunch of them.

 

[James Thomson]

If you plan on staying with casting, you will probably be better off going ahead and buying the bullet sizer press from RCBS or Lyman. Yes it costs a bit of money but it will last you a life time. Everything interchanges on these two sizers. I've loaded the 124grain RCBS trancated for 9mm and put thousands through my RCBS sizer. They shoot very accurate. Check it out. Good luck and welcome to casting.