Lee molds.... sigh

[HammerMTB]

Got a new 6-banger for Christmas... the 452-255RF. I like the boolit, already have a 2-holer. I wanted more production, so the 6er was a natural choice.
But, with a new Lee mold come all the attendant prep steps.
"Whittled" any burrs from the part lines. Soaked the mold in mineral spirits overnight. I like release agent, so shot some on there and wiped off the excess from the faces. A bit of Bullshop Sprue lube and she's ready to go....
Got the pot hot and got to trying it out. Like all 6-bangers, it takes a bit to warm up, but I have a routine to minimize the time and rejects, so in a bit it was making boolits. I tried pressure pouring and air pouring cause I find some molds seem to like one or the other. This one is more consistent with pressure pouring, and the smaller sprues are fine by me.
Made enough to check- 30 or 40 I guess- and shut down to find out what it was making.
They are .453 over most of the bearing area and .4535-.454 right at the base. Perfect! I'll shoot those without even sizing!
But they're 240-242 grain....
Funny
The 2-holer makes 250-251 grain boos.
If I understand the construction method of the Lee molds, you'd think the cavitys would come out real consistent. These are consistent to one another, but not to a 2 cavity mold made less than a year earlier....
I've got enough of these Lee molds I guess I ought to get used to some of their idiosyncracies. Been thinking about it and as long as I'm not mixing boos from the 6-cav and 2-can molds, it's prolly nothing to bother over.
Just funny is all....
I s'pose all of y'all have had the experience if you've bought enough molds?

[sagacious]

What's your alloy? 242grs is only a 3% difference off nominal, which is hardly enough to notice.

I have that same 6-cavity mold, and the dimensional measurements are the same as yours. I usually pour with a softer alloy in that one, and because of the long bearing surface, it works very well for carbine loads. Occasionally I'll use ww alloy when I need a little harder bullet for revolver use, but the weight disaparity from nominal is negligable.

Best of luck, enjoy.

[Shiloh]

. Occasionally I'll use ww alloy when I need a little harder bullet for revolver use, but the weight disaparity from nominal is negligable.

Best of luck, enjoy.

I find that a softer alloy works pretty well in revolvers also.

Shiloh

[HammerMTB]

What's your alloy? 242grs is only a 3% difference off nominal, which is hardly enough to notice.

I have that same 6-cavity mold, and the dimensional measurements are the same as yours. I usually pour with a softer alloy in that one, and because of the long bearing surface, it works very well for carbine loads. Occasionally I'll use ww alloy when I need a little harder bullet for revolver use, but the weight disaparity from nominal is negligable.

Best of luck, enjoy.

I've made these in WW alloy, but this batch was Pb/WW 50/50. That has been working for me up to 1500FPS in other cals, so I thought I'd try it here, where in my BH it will be ~1000FPS

That's part of trying to make my WW go further, and use some of the soft Pb I have in the bucket.

[leadman]

Yes, I have the 2 hole 38 cal 158gr RFN and the 6 holer of the "same" bullet. Both are different.

[jforwel]

This is interesting. I used some Christmas money to buy a Lee 20lb pot and a six cavity .44-200gr RNFP for my Ruger .44 Special.

But from Hammer's post I have a question, What does pressure and air pouring mean?

I am a one year vetera..........ahhhh, I mean rookie.

[swheeler]

pressure= nozzle against sprue plate and air pour is leaving a gap.

[lwknight]

Lee molds are like a box of chocolates. You never know what you will get.
My 429-240 RN casts 248 grain boolits in 3% tin.

[swheeler]

my C358/158swc casts a WW bullet that weighs 169 gr lubed and checked, I like it!

[sagacious]

I find that a softer alloy works pretty well in revolvers also.

Shiloh

Yup, same here.

[jforwel]

Thanks swheeler, I am now anxious to try both methods when the pot arrives.

[yondering]

Hammer, can you measure a difference in length between the 2-cavity and 6-cavity boolits? I wonder if the cherry was inserted a little deeper in the 2-cavity mold? Are the meplat diameters the same?

Merry Christmas!

[HammerMTB]

Hammer, can you measure a difference in length between the 2-cavity and 6-cavity boolits? I wonder if the cherry was inserted a little deeper in the 2-cavity mold? Are the meplat diameters the same?

Merry Christmas!

I'll sure check those and reply back here, Dan, but right now it's time to go to work.
Question, tho, for any in the know about the Lee mold-making process.
Do they use a cherry, as all iron (and I suppose brass too) mold makers do?
Or do they use a CNC process and bore the mold ID?

Merry Christmas right back at ya!
And tho it's in another thread, good to see you found time to bust a few caps!

[swheeler]

I'll sure check those and reply back here, Dan, but right now it's time to go to work.
Question, tho, for any in the know about the Lee mold-making process.
Do they use a cherry, as all iron (and I suppose brass too) mold makers do?
Or do they use a CNC process and bore the mold ID?

Merry Christmas right back at ya!
And tho it's in another thread, good to see you found time to bust a few caps!

No cherries, lathe bored with a form tool .

[rhead]

Are the lube grooves the same width and depth? Do the driving bands have the same bearing surface. I have a Lyman 2 holer that has a larger percentage difference than that and Lyman insist that it is within their manufacturing specs. I will admit that the difference in group size with the 3 different possibilities is measurable but not significant outside of competition.

[HammerMTB]

Hammer, can you measure a difference in length between the 2-cavity and 6-cavity boolits? I wonder if the cherry was inserted a little deeper in the 2-cavity mold? Are the meplat diameters the same?

So, the length is only .001" different. I can't imagine that is 10 grains, but maybe it is. I thought of finding a spot of lead about the right dia and weighing it to see if that might be all it is.
Meplat is the same within the tolerance of my eye to line up the edges of the meplat to the mike faces.
I had one other thought- I had 50/50 WW/Pb and had added some tin for fillout.
Then I added to fill the pot, but didn't add more tin. Wonder if this is just boolit fillout? I will find out next time by replenishing the tin to the mix. The tin isn't heavier, so if the boo is heavier, it's because of fillout.

[HammerMTB]

Well, I got around to the next step, and added some tin to see if it was just boolit fillout causing the weight difference.
It was not.
In appearance, the only diff was with more tin they are a bit more shiney, and at that just a tiny bit.
I added 1.5 oz to 10 lbs.
Just did the math, that's only 1%, but it wasn't the issue.
I made 350 boos, and there's nothing wrong with them, they just don't happen to be exactly the same as the 2-cav mold I have with the same appearance.
I think I'll shoot a bunch of 'em and give 'em their rightful destiny.

[bohokii]

i have a hard enough time making 2 good bullets at a time i doubt 4 out of 6 would be decent if i had one

[DukeInFlorida]

I find that the more cavities, the easier it is to run the mold properly.
I attribute the difference to their being more mold mass to even out the heat changes. The 2 cav molds seems to heat up too fast, and cool down too fast, making timing of the cycles critical. With the 5-6 cav molds, there's more metal mass in the mold, and they are less sensitive to that change in temp. Even if I m off a few seconds in my timing of cycles, the mold still performs for me.

i have a hard enough time making 2 good bullets at a time i doubt 4 out of 6 would be decent if i had one

[Onlymenotu]

Hammer have you tryed ditching the mold release spray? cleaning it up and just casting if the mold is hot enuff * scence you already said you leemented it* you shouldn't realy need it ... you might be superized in the size differance......