MP mold problem

[Ozarklongshot]

I know this problem is me and I just haven't figured it out. I have a dozen MP molds and never had the following problem.

It's a .357-125 for my 9mm's

The boolits stick in the mold at their bases on the opposite side from the pin guides. The lube grooves seem very "square" compared to some of the others. I end up losing heat in the pins from fiddling with the mold. The boolits often twist over trying to open the mold, damaging the drive band and the HP. I have repeatedly cleaned the mold and it's been through at least 6 heat cycles in the mold oven. The cavities that stick seem to be random and I can detect no flaw in the machining. It's usable but the cull rate is above 30% (not good)

Any ideas ?

[happy7]

Run it as hot as you can without smearing lead would be my first thought.

[MtGun44]

Do you invert the mold when opening? I cut the sprue, then flip the mold
upside down, then open it, and wiggle a touch, leaves boolits sitting there
on the bases. Might help a bit.
Any chance that there are burrs? Maybe lapping lightly with fine lapping
compound.

Bill

[Forrest r]

I had 1 of his 44cal (256/keith style bullet) that did the same thing. After close examination of the cavities I found that the mold was cut so well it had extremely sharp edges/flow lines.Used a cast bullet as a lap & toothpaste as lapping compound & softened the edges of the mold. It didn't take long (maybe 15 seconds a cavity with a cordless drill on low) & the bullets fall out of the mold now.

I tried running the mold hotter at 1st, no die, all I got was frosted boolits. The other thing I do to his molds (have 7 of them now) is polish the hp pins to smooth out the tooling marks. The penta points seem to have the most & the boolits tend to stick to them more than the round hp pins. I normally cast with a cocktail of different pins in the 4 cavity molds & polishing the pins really helped.

Don't give up on the mold just lap it & enjoy.

[Ben]

This may be what your mold needs ?

http://castboolits.gunloads.com/showthread.php?47669-More-quot-Lee-Lementing-quot

[Wayne S]

What alloy are you using ? I had a similar problem ,but with a different Co's mold. I was using the pot with a # 2 mix. When I switched to the straight WW pot, Life was good, the DB's weren't as sharp but the bullets fell out.

[CPL Lou]

After you cut the sprue, turn the mold upside down. Tap the hinge with a wooden mallet to start the mold opening. Let the tap separate the halves. Then open all the way normally, keeping the mold inverted. With the mold open, pause before tapping the hinge again to drop the boolits. I have to run my pot at about *750 and run a little fast with the pours to compensate for the extra cool down time with the halves open, but it works for me. Also, try using a pencil and 'write' in the corners and all over the pin tips. Will help with the stickiness.

CPL Lou

[hermans]

With my one MP mold I had the same problem. I agree with CPL Lou on this one, my mold just needs to sit about 5 seconds after the sprue is cut and the mold opened, then only a light tap is needed to free all 4 boolits from the cavities.
Enjoy this work of art, once you have it figured out!

[Ozarklongshot]

Thanks guys its very helpful, The mix (50/50 pb/coww) works great with the other molds. In fact when I get tired of messing with the 125 I grab the .357-95 mp which is very similar in that it has very squared off lube groove and it works wonderfully, just clickin away as fast as I can go. I may try running a bit hotter. I've been right at 700º may up it a bit. I'll try as many non-abrasive methods as I can before doing any polishing. I can get a boolit centered on a drill rod easily enough. Just love my molds to much to risk them until all else fails. Sincerely Thanks again

BTW I do cut sprue (by hand no hammer) flip/open/push pins. The ones that dont hang up on opening just jump off the pins when I push them out.

[happy7]

You don't necessarily need to run the melt hotter. Just run the mold faster or cool it less as the case may be, and run the MOLD hotter.

[Ozarklongshot]

After you cut the sprue, turn the mold upside down. Tap the hinge with a wooden mallet to start the mold opening. Let the tap separate the halves. Then open all the way normally, keeping the mold inverted. With the mold open, pause before tapping the hinge again to drop the boolits. I have to run my pot at about *750 and run a little fast with the pours to compensate for the extra cool down time with the halves open, but it works for me. Also, try using a pencil and 'write' in the corners and all over the pin tips. Will help with the stickiness.

CPL Lou

Just a quick note to tell you that this worked beautifully. 2 pots in today with less than 10 culls. I just cut the sprue, flip and tap the hinge with a piece of mule deer antler. The mold pops open with the bullets still on the pin side. Push pins and they just jump off. It's just a tiny bit slower than most of my molds but its as fast as I can realistically run and get quality bullets. Thanks you saved me a lot of aggravation !!

[CPL Lou]

I'm glad it helped.

CPL Lou