Lee .356 bullet mold casting large bullets

[atygrit]

I have a new .356, 6 cavity bullet mold that is producing oversized and out of round bullets.

Out of probably 1,500 that I cast in one session, I measured a sample of 50 bullets.

.358 15
.359 4
.360 9
.361 3
.362 4
.363 6
.364 3
.365 3
.366 2
.373 1

I used a Starrett micrometer to measure these.

The out of round was .359-.365, .365-.358, .365-357 and no there did not appear to be anything on the mold preventing a good tight fit while I was casting.

I didn’t realize these were so large until I tried to use my Lee .356 sizer and nearly ripped my press off my bench trying to size them. So, what could be causing these issues? I plan on calling Lee on Monday to find out if they think I have a bad mold or something.

174396This is an example of what I'm seeing, this bullet measures .371 and it has a coating of Hi-Tek. I scraped the Hi-Tek to see if it was overly thick, and appeared to be very thin, so I don't think it was increasing the size. If it is, it certainly isn't increasing it that much.

[Walter Laich]

couple of thoughts:

try measuring before the coating

what alloy are you using?

if still too large a call to Lee would be in order. Some do slip through their QC

[atygrit]

The list of bullets were without coating, I just had a picture of one of the bullets with coating. Also, using 92-6-2 lead for the bullets.

[Cowboy_Dan]

If you put your hand ont the spru lever while you are casting it will cam the mould open a bit. Don't know if you are doing this, but it is a possibility.

[runfiverun]

keep your thumb off the cutter handle.

[Moonie]

If you put any pressure on the spru cutter handle it will cause exactly this issue.

[OS OK]

Are you absolutely sure that there is no foreign matter or little specs of lead on the closure faces of the mold, or you may smoke the faces of the mold heavily when smoking the cavities...I don't notice you mention smoking, some still do that.
It doesn't take too much debris to keep them open a bit...the mold closure mark on that round looks a little wider than usual.

[atygrit]

An update. I purchased the mold through Amazon and I was able to return it. It was fun explaining to the guy that sounded like he was from overseas what was wrong with the bullet mold.;-)

The new one I received, worked a lot better, but some of the cast rounds were still a touch too large, but NO WHERE near what the first mold was producing. I'm going to say the problems with the new mold are probably from me, but we'll see the more I use it.

[Ole Joe Clarke]

You are blessed that the bullets were large enough to size and lube. The 6 cavity 40 cal dropped bullets undersized and were useless.

[dragon813gt]

A Lee mold casting oversize bullets? Better go play the lottery because you are a lucky individual :D