Finned bullets, new mold

[Pawhands]

I have a pair of steel mold blocks (mehanite) that cast finned bullets, like this:

http://www.gunweek.com/2004/pix1201arc/5.jpg

(picture hot linked from this article at Gunweek: Solving Some Common Problems Encountered when Casting Bullets (http://www.gunweek.com/2004/feature1201.html))


There is no lead on the mold surfaces, the mold is brand new and I have cast less than 10 bullets from it.
I don't think it is the alignment pins either.


Would it work to clamp the two mold halves in a vise overnight? Or will the tension in the steel make it go back to normal again once it is heated?

Do any of you have any suggestions on how to solve this problem?

Thanks,
Pawhands

[felix]

Pawhands, I do not think Lyman was using coppered iron (a Mehanite Corporation like alloy) when your mold was made. Coppered iron molds do not typically warp under our user circumstances. That's why the copper inclusions were introduced way back when. A mold like you have should be returned to the maker. If indeed Lyman, I think they will supply you with a new one. I think, but not sure, Lyman is now using coppered iron as well as most everyone else. ... felix

[rr4406pak]

I have a LEE mold that does this went it gets really hot.
I doubt LEE would let me return it...

[Pawhands]

Pawhands, I do not think Lyman was using coppered iron (a Mehanite Corporation like alloy) when your mold was made.

It is not Lyman, it's NEI. Forgot to mention ;-)

[454PB]

Sometimes when moulds do this, you can hold them up to a bright light and see what is preventing them from closing completely. It doesn't take much of a ding or imperfection in alignment to cause it.

[GSM]

Pawhands:

Check for a gap WITH THE HANDLES ATTACHED.

I finally broke down and bought a pair of NEI's modified handles and it reduced practically all of the side finning I was having - still getting a little on the base, but it may work out eventually. Mould blocks were also Meehanite, 4 cavity.

[floodgate]

GSM:

"Check for a gap WITH THE HANDLES ATTACHED."

Always a good idea, especially with the older Lyman handles. Make sure (with a slip of paper) that the handle jaws do not bear on the inner face of the slots ANYWHERE but on the screws. A little file work on the inner face of the jaws will cure this, if it is the problem.

floodgate

[Old Ironsights]

Darn. I was hoping this thread would be about casting Flechettes... Those fins are a bugger... ;)

[Bass Ackward]

You got the under water version of the 429421 made for shooting fish. :grin:

[Pawhands]

Pawhands:

Check for a gap WITH THE HANDLES ATTACHED.


The gap is there both when the handles are attached and off. I'll place it between the vise jaws overnight and we'll see what happens.

[leftiye]

Like 454pb said, hold it up to a good light source (window is the best - not at night), see where it is "high"- what part is holding it apart (might be the dowel pin holes), carefully draw file the mold faces flat. Or send it back, it's not much use as it is. The part that a flat smooth mill bastard file starts to cut is also the "high" place. As long as you don't file the sides (edges) of the cavities, you won't mess it up. Maybe push out the locating pins first, and re insert them when done.