bullets out of round... solutions?

Ok. So I bought 2 lee molds. I know not a great start, but I had to start somewhere. In any case I got a 124g .356 9mm mold, and a .358 38/357 mold. the 9mm seem to be fine. the 38/357 mold seems to be dropping out of round after the first batch. I cast a 2nd test batch today and found a little bit of junk between the plates. I cleaned it up and its still slightly out or round. the mold is supposed to be .358. after casting I am getting .357 to .361. after sizing there are a few spots that are not getting sized, and I am measuring .357 to .359. on a side note I am sizing at .359 for my cylinder throat size. Other than cleaning I am not sure how to deal with this...

Put some 2-cycle engine oil on a cotton rag. Then..I would use a torch, others may use a stove top or electric hotplate. Get that mold hot!... enough that it takes eight seconds for the sprue puddle to solidify.

Once you've got it up to temperature open the sprue open the mold and wipe it down with the oily rag. Scrub everything you're going to see some steam form this is normal. Scrub inside the cavities are both sides of the sprue plate.

When the lead is soft the scrubbing is easy. Only a couple cast where the mold is up to temperature will remove any excess oil.

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Can you put pictures of the mold from different angles?

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Your mold is not out of round, the blocks are out of alignment. Check the pins to see if perhaps they are not correctly engaging the female socket in the opposing block. Bring the mold up to temp, cast some samples and measure with a micrometer diagonally on each side of the casting close to the mold seam. They should be equal when the pins are in correct position.

Are these 6 cav or 2 cav molds? Sometimes holding all three handles if a 6 cav mold is used will also cause the blocks to shift.

This most often happens when the molds are not heat cycled at least three times before casting and the pins are not settled in position.

Do 2 steps with your mold:

* Hold the mold handles and move them back and forth. If they wobble, the handle bolt is loose and needs tightening. This looseness when squeezing the handles while casting will cause the bullets to be out of round
* With the handles tightened, squeeze the mold blocks together and hold them up to a strong light. If you can see daylight, means the pins are out of alignment…. If there is no lead on one mold half and not the other

Same, out of round with Lee 44mag 429-200-RF . Cant use it when sizing to .430"
.429" to .431" oval. Accuracy not good.

The Lee 9mm 356-120-TC is out of round also. Ok when sizing to .356"

Both 2 cavity. Been casting for 50 years, only happens with Lee.

Lee Precision has a guarantee policy … send the molds if you can’t fix them …

I really didn't take time to give a through reading of your post and the responses. I will just say that there has never been a two piece bullet mold that is 100% round. The out or roundness varies from mold maker to mold maker and mold to mold. A traditional resizing in a good dies generally takes care of the problem. But even if you powder coat, it probably isn't as much a problem as you think. Any bullet, once it has traveled it's length in a barrel will be sized to the exact fit of the barrel. Lee molds are cheap, cheap, cheap, but for the most part work. Just shoot the bullets and come back if there is a problem.

If it is a new mold, I would send it back to Lee. They are supposed to be fairly good about standing behind their products when they don't work correctly.

Used mold? Do as Char-Gar said, shoot them before taking drastic measures.

Robert

If you can get Lee to replace it(if they have any in stock) do that. Otherwise, as long as you can seat them in the case and chamber them, they should work. As soon as the boolit enters the bore, it will become perfectly round, sized by the bore.

I have 3 molds en route to Lee for this very reason. 2 are misaligned (pins not indexing correctly) and one has a large gap (warped maybe?). The 2 misindexing molds are a 309-150 RNFPGC for the 30-30 and a 358-125 RNFP for the 38/9MM. All my bullets are cock-eyed and have a serious part line.

The "warped" mold is a 311-155 GC mold for the SKS. It has a discernable gap in the middle and the ends of the mold touch. The bullets exhibit "flashing" and large mold seams.

There are no lead smears on the mold block faces and these are the newer "dual pin" design vs. the older "V block" alignment style.

What I would recommend is clean the blocks really well of oil grease and debris. Look under magnification for butts dings and or rough areas. then lightly coat one block with a dark grease very lightly and evenly. Close blocks slowly and carefully to the same pressure as when casting. Open carefully and look for the spots where grease has transferred. these spots are the high spots holding the blocks apart.

I had a set of the lees with the vee rails that had a radius at the block rail that held them open a little light work removing it with a fine hacksaw blade and all was well.