Hollowbase Mold

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Last Post 03 October 2015

CBA Member

cove posted this 15 September 2015

I recently purchased a 360 148gr HBWC mold from N.O.E. Using a mix of approximately 30-1 the mold is filling out pretty well. The skirt at the base is not as sharp as I would like it, but the bullets are accurate. The biggest problem I am having is getting the bullet to release from the hollowbase pin. I have polished the pin, blued it, given it a coat of moly, a coat of graphite, and smoked it, but the bullet at times has to be removed with pliers. Anyone have any experience with these molds or any suggestions?

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Standard Member

onondaga posted this 16 September 2015

http://castbulletassoc.org/view_user.php?id=5751>cove

You have the symptoms of a burr or undercut defect or a reverse tapered area on the mold pin. High optical magnification should find a burr. A mechanical caliper beak set should find a reversed taper area on the pin.

Scribbling on the pin with a regular #2 pencil leaves a coating that acts as an anti-flux. If you have sticking when you pencil the pin, you have a defect that is catching.

The pin may need to be polished, re-tapered or replaced. If you can point out the defect, it should be easily under warranty.

Gary

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CBA Member

358156hp posted this 17 September 2015

Hollowpoint and hollowbase pins need to be really, really hot or the bullets will stick. Do you preheat your moulds? Using a hot plate to preheat NOE pin type moulds, then maintaining a pretty rapid casting pace should work out for you.

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CBA Member

cove posted this 22 September 2015

I have been experimenting further with casting technique for the 38cal hollowbase mold. The suggestion concerning reverse taper on the pin lead me to closely examine the pin and it was obvious that the moly coating I had applied was uneven and had small irregularities. The pin was cleaned up and the mold started releasing the bullet upon opening or with a light tap. I also found that when using a friends bottom pour pot the bases were sharper, but bullets tended to stick. I have been an avid dipper guy, but now feel I need to try bottom pour again. Thanks for the feed back. Cove.

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CBA Member

Dale53 posted this 03 October 2015

I have a number of Mihec hollow point moulds. I treat the pins with “mold release” from time to time. Mold release is merely microfine graphite in denatured alcohol. I use a q-tip and lightly coat the surface of the pin which creates the hollow point from time to time. I do NOT do it every time I use the mold as you CAN get build up.

When I open the mold, the bullets fall off the pin. Before I started doing that, the bullets STUCK to the pin.

Now, I have nothing but smiles when I use these fine hollow point molds.

My experience with NOE molds is equally good but I don't have any NOE hollow point or base molds...just solid point and base.