bad luck with lee bullet molds.

[BigGun]

hello guys, I am going to run this by all of you for comments and ideas.
to start with I cast for 8 calibers .22,.243, .30, .357, .44 man &special, 45 acp, 45lc,
will soon start 7mm, and 8mm.
the molds I am having bad luck with are .30 cal 150&170 gr lee's
the 170 gr mold has had 1500 bullet from it, then started getting fins on the seam
at the base on front cavity, (have been very carefull with this mold "not closing
hard,not dropped,") I treat all of my molds that way lee or lyman, Last fall I had 2
hand gun bullet molds (lee) that I had to trash because of this Finn problem, Both
of those molds were 38/757 150 gr. they both developed the fin problem at around
1500 bullets , also on the front cavity, I looked at the blocks under mag glass
several times and could not find what was holding the blocks apart.
Have inspected the .30 170 gr mold blocks several times , have smoked the blocks
inner faces and can't find any high spots or lead spots,.
I have a 45 acp and .44 both 200 gr molds (lees) 6 cavity. The 45 acp mold has made about 10000 bullets , it is now starting to get fins on the front 2 cavities.
again can't find what is holding the blocks apart.
At this point I don't feel that I can invest in another mold. I started casting
bullets in 1970, and still have the first lyman mold that I purchased and It still
makes good bullets.
What now?
Ted Kelley

[theperfessor]

ted -

Sounds like you've looked at a lot of the things that could cause your problem. On the 6 cav Lees the alignment pin-and-socket mechanism is made of steel pressed into aluminum, with the pin shaped like a rounded cone. The Lyman is a steel ball-nose pin pressed into a ferrous block that aligns directly into the other ferrous block.

Aluminum expands at a greater rate than ferrous materials. I wonder if a relatively loose press fit might allow the Lee's pin/socket parts to come loose enough under casting temperature to shift in or out under gentle impact enough to cause your problem?

It is not something you would likely get w/a steel mold using steel pins.

Just a thought.:-D

[BigGun]

The Prefessor:
I will check that out on my 6 cavity mold.
thanks
ted kelley

[Bass Ackward]

Could be it just warped.

Metals have stresses in them from the manufacturing processes. If not relieved before, machining, then it will come out as the mold is constructed .... or used. Now, understanding how Lee spits these things out, I seriously don't think they take steps to perform this task. And I am not blaming Lee, just the way things are.

Heat or I should say excess heat can bring it out quick. So can rapid cooling, like on a wet pad or so. That's how I lost an RCBS. Otherwise it shows from the standard heating and cooling cycle.

Preheating the mold in the pot takes the mold to much higher temps than casting from cold if you leave it in too long. Even though these are 6 cavity molds, I only mold with the four inside cavities to help control heat and relieve stress on the sprue plate screw just because it's a Lee. :grin: But I am a patient caster also. It rewards me with more uniform bullets and so far, longer mold life.

[Lloyd Smale]

the perfesson hit on a common problem ive had with lee molds. One of the alignment pins may have backed out just a smidge. Ive sent many molds back to lee to get replaced because the alignment pins wouldnt stay put. It also only takes a mnute ammount of lead on the face to cause this and its hard to see on a lee mold. Make sure too that when you close your spruce plate it isnt torqueing the mold open just a touch. Ive used alot of lee molds and have destroyed alot of them. Ive seen the spruce plate on a lee mold warp but havent yet seen the blocks warp.

[mooman76]

Have you taken a good look at the mould once it heats up. I have allot of Lee moulds and some have cranked out allot of bullets and I have never had that problem. I tap the mould lightly after closing it to make sure it is together tight and make sure it is lubed good so it moves freely. I use WD40 and spray it on when the mould is hot. Makes a good mould release too!

[mroliver77]

I only have a couple of the smaller (1&2) Lees but if Leemented and usually flaaten the sprue plate they give good service. I use a wet pad to cool all my molds( well mebbe not .22) and have never had warpage problems. Do I understand correctly the finning is near the front of the boolit? The alignment setup in the small Lees can be a source of puzzlement. Any problem like you have I have always found a speck or burr causing it.
I for one am amazed that Lee can make a workable mold with handles and sell it to a distributer
for around $10.
J