New MP mold on the way

Reloader762

Active Member
Thanks for all the feedback, I feel like I made a good choice. I've cast with both iron and aluminum molds all my life so this will be my first brass mold, any pointers about casting with brass as opposed to casting with the other types of molds would be appreciated.
 

CWLONGSHOT

Well-Known Member
I have a 312-140 its a dandy in my 32/20 single shot!!
Your gonna love it!!

All my MP molds have been brass. They cast beautifully and hold consistent heat better.

CW
 
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Spindrift

Well-Known Member
This is how I do it, with a new MP HP- mould

1) clean it, I use acetone
2) carefully inspect the HP pins. They're usually fine, but any burrs should be sanded away
3) take it through a couple of heat cycles in an oven.
4) when installing the HP pins, make sure the sliding pins are moving freely, under gravity. This is often accomplished by not tightening them completely
5) preheating the mould on a hot plate is extremely helpful
6) Starting the casting session with the melt slightly on the hot side is also helpful. I turn down the pot as I start, allowing temp to drop to the sweet spot (725F, for me).
7) MP designs often have deep lube grooves. If you find a tendency towards riveting by the mould part- line, it may help if you tighten the hinge bolt of your handle.

Good luck!
 

Ian

Notorious member
I take them out of the box, clean the cavities with a Q-tip and alcohol, debur the pins, loosen the pin guide rods half a turn so they slide freely, put a very light, caramel haze of butane smoke in the cavities and tips of pins, mount the handles, lube the bottom of the sprue plate and pivot bolt,dunk the front bottom edge in the melt until lead won't stick anymore and the pivot pin starts to smoke, and start casting.

Preheating a few time oxidizes the cavities slightly and prevents "tinning" of a fresh mould. A little soot accomplishes the same thing only faster and by the time it wears off, the patina has started.
 

Reloader762

Active Member
Mold was waiting on my desk when I got in from work today, three day from across the pond after making a stop in five different countries, that's just amazing considering how long it takes to get some things here in the states. The mold is a work of art that's a sight to behold, I might have to give myself another as a birthday present here soon. Tomorrow is cleanup, assembly and heat cycle day, so I can do some casting on Saturday.
 

Reloader762

Active Member
Cast around 200 bullets with the new MP mold yesterday and had a great experience. Cleaned everything and put the mold together and made the proper adjustments to the pins, heat cycled the mold three times, lubed it up and put it on the hot plate for about forty minutes while I took care of the pot and got it up to around 725 degrees. The first pour came out near perfect with only a slight wrinkle on one bullet on the back driving band which after coating and size you can't see. Couple of taps on the mold handle henge bolt to open the mold and the bullet dropped right off the pins with no hangups. I think I will be buying another MP mold in a handgun caliber when it comes back in stock. Will post some pics when I get back out in the shop today.
 

Mainiac

Well-Known Member
His 8 cavity molds are magic.i have a 275 copy,that i open and all 8 fall out,,dont even have to tap the hinge bolt. A new 147rcbs clone,i just got,,7 of the 8 cavities,,falls out upon opening.
 

Reloader762

Active Member
Reloader, what powder is that? I like that look!
It's a powder that a good friend that goes by the name of John's Hand Loading on YT sent me. It was a mix of several powders, one of the local powder coat co. mixed up and gave him, so he shared some of it with several of us that he knew on the Georgia Shooting Connection and The Reloaders Network.
 

Ian

Notorious member
Ahhh, "leftovers bin" powder, probably some of the best. I have a buddy who did a bunch of odds and ends in his shop with crap off off the powder room floor, looked like granite, very nice, never will be able to duplicate the batch.

Did you try putting any gas checks on the Hunter before coating?