Bullet out of round by .007 - did I cause this?

[garandsrus]

Hi,

I purchased a new Lee 500-360M Improved Minie Ball Bullet Mold drops bullets at .500 if measured from one parting line to the other and .507 if measured 90 degrees from the parting lines. The alloy is pure lead.

Is this mold just out of specs or is there something I could be doing (other than not closing the mold!) that would cause the problem? I measured about 10 bullets and they are all consistent.

I pushed several "as cast" bullets through my .50 cal muzzle loader barrel and had to force them through. The rifling was engraved in the bullet when it came out.

Should I just size the bullets to .500? If I size them, the driving band will be .501 but the center of mass will be a little off center, won't it? I would expect this to result in poor accuracy.

Thanks,
John

[redneckdan]

my lee tumble lube .45 tc mold was about .009 out of round, close the mold and hold it up to a bright light, see if you can see light shining though the block partition

[Bass Ackward]

John,

When using pure lead, one expects things to go .... out of round. Some call it obturation and sometimes it is just flat out deformation.

We used to agonize over out of roundness and now many people build this in by beagling a mold. Since they are happy with their results, it can't be doing that much that a barrel (sizer) doesn't correct.

If I have my choice, I prefer perfect. But I learned to live with what I get. I would still check that mold out. You could have some dirt on the face or one of the pins might be out a little too far.

Then shoot some and report how they flew.

[44man]

I would say the blocks are not closing all the way. Very hard to tell with a Lee because of the position of the locating pins. They block a straight through view. A double cavity can be seen through right between the cavities but a single is blocked. Being that much out of round, you should see the gap right at the top of the mould.
Make sure there is no tiny chunk of lead stuck to one of the pins or in any recess.
I have had to deepen the slots for the pins and work on the angle locks on the ends of several moulds to get them to close.
Lee should replace the mould if you don't find anything holding the blocks open.

[Buckshot]

................As that is a Minie' it will have the auto centering core pin. Check that over REALLY well. It has a band around it designed to fit into a mating groove in the blocks. You can have tag ends, pigs ears, swarf or other alien artifacts around and about that thing that will keep the blocks from closing completely. Also, since the core pin is rivited to the centering plate, check to make sure it isn't bent.

................Buckshot

[buck1]

These guys give sound advice!
One thing I have noticed..........
A boolit can be out of round and shoot fine as long as, it is balanced. If the extra lead is equil and oppisite from each other its still balanced.

FWIW....Buck

[Blackwater]

I had a similar problem recently, and though I THOUGHT I'd checked the mould for tiny bits of lead, I was wrong. Had to turn the mould upside down and look close, and found a tiny piece of alloy keeping it from closing properly. THEN .... I realized that if I turned the mould upside down while casting occasionally, and checked the parting line top and bottom before pouring the alloy, I rarely had that problem again. I was dumping my sprues back into the melt, and apparently an occasional splash got a tiny droplet back in the mould.

I hate it when I catch myself doing something like that! [smilie=1:

[44man]

You fellas would have a good laugh if you ever watched my friend cast. Lead will be overflowing all over the mould, the garage floor and bench is full of splashes and he has enough drops of lead jammed between the blocks for half a boolit. I guess you could call it the original "Beagling."
I dropped in on him once and he had 2 pots running and about 5 moulds. This huge bench was piled with boxes of boolits and round balls, maybe 5000 or so. He had cast for 8 hours. I inspected them and didn't find a single good one in the bunch. None were filled out and all were wrinkled bad.
He won't read this so I am safe!

[garandsrus]

Thanks everyone... I looked at the mold and did find some small pieces of lead in the area where the pin self centers. I have removed them and will try casting some to see what happens!

John