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View Full Version : MP Molds and the 429640



Mal Paso
07-16-2012, 01:08 PM
A bunch of us got a new toy. The 429640 4 cavity cramer mold. I wish I'd had the patience to let the mold patina like my #503 but 3 heat cycles was all I could stand before putting it under the pot. My sweet spot was 690F and a hair less than 3 pours a minute with a generously preheated mold.

I'd like to get some Alloy/Load Recommendations and has anyone tried Pat Marlin's Gas Check on this Boolit?

[QUOTE=snuffy;
I really like the new location/guide pins. Never a hang-up, simpler closure. Did anybody else notice the guide rods for the HP pins are made with allen sockets in the end. The allen wrench for the sprue plate pivot bolt lock/set screw fits the guide pins!:mrgreen: Real easy to get them tight, no marring them with a pliers.
[/QUOTE]

Does anyone have suggestions for fitting the guide pins that are a little tight?

The 429640 mold opens easily with no tapping on the handle just a tap to slide the pins out. Maybe another tap or two for boolits hanging on the penta pins. The #503 always took a tap to open until I ( Gasp ) hand lapped it with some fine compound. I think it's the Keith Design that hangs as it cools but they just fall out now. All the Tapping was what probably walked the alignment pins out and put extra wear on the mold too. I also changed the sprue plate roll pin to a bolt. Not sure I would recommend this method as the bolt does loosen but I don't get bumps on the bottom of the Boolit. The New 429460 in front has conical alignment pins and the sprue plate is much tighter. The #503 in back has cast about 24,000 of the most accurate Boolits I've shot.

captaint
07-17-2012, 04:17 PM
Mal - One of the first things I do when a new MP HP comes in the door is to remove the alignment pins and polish them in my drill. 400 paper and oil. Doesn't completely solve the binding issue, but it helps. I usually try swapping them around too. Often that helps. I like to get them to slide out when I tap the handle bolt. Often they slide out when I open the mold halves. Try wiping a little Bullplate or similar on also. enjoy Mike

white eagle
07-17-2012, 04:45 PM
what will happen is after time they will loosen up and work freely
for now what you can do is use a touch of that bull plate on the pins where they
slide in and out of the mold
they are crafted with tight tolerances a fine piece of machining