Incomplete fill on hollowpoint mold

[mongoose33]

Bought a NOE hollowpoint mold, the one designed for HyTek coating or, presumably, PC.

When it works, it works nicely. But I'm struggling to get complete fill-out of the hollowpoint cavity, as evidenced by the two boolits on the left:

141358

Is this just a consequence of pins that are just too cool, and thus, the alloy is freezing before it has a chance to fill out the hollowpoint?

[Yodogsandman]

At least to me, it looks like you aren't giving the pins a shake or a jiggle when upside down after dumping the boolits when you're closing the mold. So, shake em, jiggle them or tap them while you have the mold inverted and close the mold while it's still upside down to align the pins right. They seem to be filled out right so, I don't think you need any more tin.

[Southern Son]

I think that the pins might be a bit cool. If it was the mould not quite closed and the pins loose, then the boolits with the flashing would be as long or probably longer than the good boolits. Just my 2 cents worth.

[Beagle333]

Looks to me like pins aren't reset. Make sure mold is upright and shake/jiggle before closing. NOE pins will move around a bit in the guide. It's pretty neat sometimes, as you can make a different looking nose if you close the mold while it is upside down. But that looks like the issue here, and it doesn't work quite as well on a round noser. The pins are extended and the lead is trying to flow down around the shaft of the HP pin. 8-)

[HATCH]

More heat and maybe a little more tin.

[Beagle333]

It's easy to figure out if it's the heat/tin or the pin seating. Just trim the flashing off back to the flat part of the HP nose on the bad boolits and measure them. Then measure the total distance of a good one. Whether it's filling out 100% or not, it should be the same from base to nose edge of HP cavity, or it is a pin issue. (A should equal B if they are seated correctly)

http://i613.photobucket.com/albums/tt214/shutupandjump/cast%20boolits/HP2_zpsv3vs0ecn.jpg

[Handloader109]

The other guys have it right! Pins are totally not back! I have two NOE HP molds for my 9mm. The first one gives me trouble. Doesn't always drop back to right location. A lot of underfils. My newer, runs great, but I do need to run it hot to fill without lines elsewhere. I end up tapping on edge of bench just as I close the mold. Nothing hard, just little bump and pins usually drop in place. The new mold just needs a shake to drop the bullets if hot enough.

[mongoose33]

It's easy to figure out if it's the heat/tin or the pin seating. Just trim the flashing off back to the flat part of the HP nose on the bad boolits and measure them. Then measure the total distance of a good one. Whether it's filling out 100% or not, it should be the same from base to nose edge of HP cavity, or it is a pin issue. (A should equal B if they are seated correctly)

http://i613.photobucket.com/albums/tt214/shutupandjump/cast%20boolits/HP2_zpsv3vs0ecn.jpg

The "B" length is .561; the bullet specs on NOE's website say it's .560 long, so that's the nominal and correct size.

The "A" length is .540 after I trim the flash, so there's something wrong.

The pin thing is something I presumed was just happening correctly; every time I think I might be figuring this casting stuff out, I run into something new like this. :)

Thank you--all of you--for the help.

[Maximumbob54]

I was making a worse example of the same mistake. This post fixed everything but you might want to scroll through the whole thread:

http://castboolits.gunloads.com/showthread.php?236897-NOE-Hollowpoint-mold&p=3210162&viewfull=1#post3210162

[mongoose33]

I just came home and pulled out the mold, and I see exactly what I was doing wrong. It's the seating of the pins that's the issue, and now I know how to do it.

Thanks to all for the help!

[mongoose33]

Thanks to all for the help. Two things solved the problem, in combination:

First was ensuring the pins are set. After the boolits drop I then flip the mold upright and tap it as I close, so the pins settle down where they're supposed to be. I had been closing it with the pins pointed down.

Second was speeding up the casting, and not allowing the mold to be open (during which time the pins are cooling) any more than necessary.

Between these two things the number of culls dropped to 20 percent or less (depending on how well I filled the mold). It's giving me these now:

141552

[Beagle333]

Those look nice! :D

[mongoose33]

Those look nice! :D

Yeah--I'm pretty proud of them. :) They drop at 128 grains; the mold is listed at 135 so the cavity must be about 7.

Next step is to PC them and see how they do. I tried setting them on a drywall screw and they're virtually perfect for doing that. I can PC the entire boolit except the cavity which is what I want.

I'll report back when I get them done and shot.

[zuke]

More heat and maybe a little more tin.

:goodpost:

[osteodoc08]

I'll have issues on my HP molds when the pins aren't up to temp. I'll let them heat soak a bit or zap em with a torch briefly. I add 1-2% tin with my COWW already.