Problems with a Lee mould... Not covered in Q&A

[TomBulls]

I have a Lee mould and I have been having a problem with it. The mould is not closing all the way, and for the life of me I cannot figure out why. The mould I am using is a 440gr .501 dia. FP-GC mould. It's almost like the mould is warped. Or something. The mould is closing fully on the ends, and there is nothing obstructing the alignment bars. On the bottom/center the mould is not fully closing and I can see light in between the blocks. Is this normal for a Lee mould? I have couple of other Lee moulds in smaller calibres and I have never had a problem like this. Does it have something to do with the fact that it is a double cavity mould and is pouring 880gr of hot-lead at a time? Is this something that the aluminum moulds can handle, or should I start looking for a steel mould from RCBS?

-thomas

[DrCaveman]

How are the bullets it drops?

If they have big fins on the nose, then it sounds like a problem. If not, then I'll bet the gap you see is working as a vent to help those monsters cool without leaving air pockets.

A bunch of my moulds will show a sliver of daylight through the cavities when I hold them at the right angle, but pour nice flat tipped bullets.

[41 mag fan]

I had this problem with my Lee .501 mold too.
Is this the first time you've used it? or have you cast with it before?
Look at your alignment pins and the cavity they sit in to see if there's lead in it, then where the handles are pinned to the mold. if you've got lead around the cavity alignment pins it will affect mold close too.
Take a propane torch and needle and heat mold and clean it out.
when mold is hot try taking the mold and laying it on a board and closing it....nototrious for Lee 2 cav.
All my Lee 2 cav molds I now lay on a board and close.

[TomBulls]

I've cast many bullets with the mould and I've checked the alignment pins & bars to see if there was any lead stuck that might be causing a misalignment. The mould casts really nice bullets that fill out completely, but there are some small fins on the sides. I'm not entirely sure if it affects accuracy, but I am debating whether or not to buy another Lee mould to replace it. If I do buy another one, and the same thing happens to that one, then I am spending the big bucks and getting the RCBS mould. I like the Lee moulds for the price and they cast a nice bullet (for the most part) but I don't feel like having to trouble shoot my moulds all the time.

-thomas

[41 mag fan]

Being cheap aluminum....how hot was your mold? And with that how long till your sprue solidified? Could be it's warped......
Before i'd buy an RCBS I'd look at NOE, Miha or Accurate

[Bill*]

I'm confused....Aren't Lee double cavity blocks using the "vee" bar system for alignment? How could you see light through the blocks with the bar blocking it. Do the bigger cavity (like .501) moulds use pins like the 6 cavity?

[462]

I have a Lee two-cavity 358-158 RF with the same problem, except it doesn't cast fins. I bought it before I quit being Lee's end-user quality control department, and tired of finding a fix. In the end, the remedy was to replace it with a six-cavity mould.

[TomBulls]

I'm confused....Aren't Lee double cavity blocks using the "vee" bar system for alignment? How could you see light through the blocks with the bar blocking it. Do the bigger cavity (like .501) moulds use pins like the 6 cavity?

The v-bar alignment pins do not go all the way across the bottom, hence light was able to shine through the bottom of mould.

[mooman76]

It is prebeagaled for you. Ever once in awhile you get a Lee mould that is tweaked abit. Have you tried setting it on a flat surface when you close it to help it align when closing? That could help.

[462]

Yep, light visible between the bottom alignment pins.

Nope, not a matter of incomplete closing. I set all moulds on a flat surface, when closing.

Nothing other than poor quality control.

[TomBulls]

I set all moulds on a flat surface, when closing.

How does that help the mould? I'm not understanding. Do you mean that I should rest the bottom of the mould on a burn proof/resistant surface while closing? Does this do something special for the mould other than help the alignment pins/v-bars line up?

-thomas

[geargnasher]

Nope, it does just that. Proper sprue plate lube (NOT what Lee says to use) helps too. If it casts round boolits the right size, don't worry about it. If it's inconsistent, or casts elliptical boolits that are larger across the side perpendicular to the parting line, put the mould in a vise, carefully align the cavity halves, and crush it closed. Or send it back.

Gear

[462]

Yep, did the crush trick, too, but light is still visible. Learned a lot, trying to get that mould right, however there comes a point when its best to move on.

I will say that when Lee makes a good mould, it's good.

[John Boy]

The mould is not closing all the way, and for the life of me I cannot figure out why. Put the mold in a vice with lead or brass shims and squeeze the daylights out of it

[Any Cal.]

I have a Lee two-cavity 358-158 RF with the same problem, except it doesn't cast fins. I bought it before I quit being Lee's end-user quality control department, and tired of finding a fix. In the end, the remedy was to replace it with a six-cavity mould.

+1 for me exactly, except I was getting fins.

[leadman]

I have the same problem with the Lee 300 aac mold I just got. Have to squeeze the handles as tight as I can to not get fins on the nose.

[MT Chambers]

There are an awful lot of great mold makers out there, most are topics on this site, life's too short to have to deal with Lee problems (at least for me).

[MBTcustom]

I think you might be worrying about nothing and making a mountain out of a mole hill. (no offence intended)
If you really want to go with a better quality mold then by all means just go for it, but the mold you are using is casting a really big boolit and small variances in boolit quality don't make as much a difference with a big boolit as they do with a small one. I dont give a darn what the mold looks like, as long as the boolits hit where you aim them. I only say this to caution you that even though you have a cheapo-beepo mold, if your gun is partial to that particular boolit, then you should stick to it. Every mold is different, even from the same manufacturer and the same run. The slightest change can screw you up. Your gun doesn't care what your mold is made of, or how much you paid for it, or how much light you can see through it, or how you have to cross both toes and stick out your tongue to get good boolits. All it knows is that a certain combination works for some unknown reason, and if I had that combo, I wouldn't care if the mold looked like a sinker clam shell, I would stick with it till the bitter end.
For instance, I found that my 358win likes the RCBS 35-200-FN mold. I got a good deal on it from midway. I thought that I would like to own a custom mold from Accurate Molds also, so I ordered one up. It was identical to the RCBS except that it had a slightly longer bore riding section, and had a slightly larger meplat. The cheap RCBS mold shoots 1.5" groups @ 100 yards. The Accurate mold shoots 2.5" at half that distance, with all things being the same. Not that I am down on Accurate Molds, quite the opposite in fact, but in this example, the rifle just did not like that slight change in profile. So guess which one gets used more?
Just my 2 cents (I got wordy so lets call it $1.50).

[Casting_40S&W]

More than likely you have lead in the alignment pins. The way Lee designed the alignment pins, gravity pulls lead down into those pins, once they are gummed up with lead, the mold will shead alittle light per say.

[paul h]

Sometimes I find that to get my lee 1 and 2 cavity molds to close properly I need to give them a light wack with my sprue cutting dowel. You don't need to beat it closed, but a light tap often gets the mold haves to settle in.