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Thread: Master Caster mold prep

  1. #1
    Boolit Bub
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    Master Caster mold prep

    I finally have my master caster setup and automation working great. Now I just need to get the molds to spit out nice bullets.

    Since Magma has poor instructions (putting it nicely) I figured I'd ask here. What do you do to prep a new magma mold? The master caster came with a bottle of lube with instructions to spray inside the mold and outside. Won't this cause wrinkled bullets? Some people mention polishing the molds, any tips for doing this?

    I tried searching the forum but couldn't find anything specific to magma, hopefully I didn't miss it.

  2. #2
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    For new molds, all I do is clean and degrease them. I don't spray the lube inside the mold cavities, as it will cause wrinkles until it wears away. I spray the tops of the molds and the tops of the sprue cutters, but only when I've got bullets in the cavities to prevent lube from coating the cavities.

    It may take as many as 40 or 50 casts to break in a new mold, but I've also had some that cast good bullets pretty much right away.

    Hope this helps.

    Fred
    After a shooting spree, they always want to take the guns away from the people who didn't do it. - William S. Burroughs.

  3. #3
    Boolit Bub
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    Thanks for the advice.

    I cleaned with soap and hot water and gave it a shot. The bullets look nice, no wrinkles. However, I'm getting a gouge along one of the seams created by the two halves of the mold. Both bullets in the mold have the same gouge. Is something not adjusted correctly with the master caster? I tried two different molds and both have the same gouge.

  4. #4
    Boolit Master MOA's Avatar
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    I scrub them in the sink under hot water and lots of dawn dish soap, dry them real good with a hair dryer and then smoke the heck out of them with the BBQ emergency starter tool, the long handled gas lighter until there is a nice coating of soot all over the cavity, run the temp up to about 800 in increments while watching the boolits for frosty or non frosty, I do water drop my boolits.

  5. #5
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    Mark2215,

    The line you're seeing is from the molds separating. One side is probably turning slightly as it opens and causes what looks like a second seam line. Those will go away on the bearing surface when the bullets are sized and lubed, but will still be visible on the ogive and nose. I haven't found them to be a problem, especially with handgun bullets.

    One thing you might do is wait a few seconds longer before opening the molds. As the alloy cools, it usually drops from the mold more easily.

    Hope this helps.

    Fred
    After a shooting spree, they always want to take the guns away from the people who didn't do it. - William S. Burroughs.

  6. #6
    Boolit Bub
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    Fred, I'll try waiting another second or two. I guess I'm just being too picky worrying about perfect bullets.

  7. #7
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    Some bullets cast better than others, but I can't really explain why. For me, they all shoot the same, so I don't worry much about it, except for wrinkled bullets. Those get remelted for a chance to come out better the next time......

    Fred
    After a shooting spree, they always want to take the guns away from the people who didn't do it. - William S. Burroughs.

  8. #8
    Boolit Buddy
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    When the sprue is cut it adds a lot of pressure on the half side of the mould connected to the sprue plate. If the moulds are not held together with enough pressure during this process you get pinch marks and the part lines, on the boolit that you describe. I've had this problem with my bullet master until I got the pressure on the braking shoes adjusted right with the correct ammount of shims. I'm not sure how this is adjusted on the MC, but I'm sure the same goes for opening the mould since the same moulds are used. I would guess there are adjustments for this.....

    Sent fra min SM-G930F via Tapatalk

  9. #9
    Boolit Bub
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    I suspected this had something to do with it. I can see the mold slightly twist when the sprue plate is opened. The master caster has two guide rails that hold the mold halves together. I've tried tightening them to the point it was difficult to move the mold and had the same problem.

  10. #10
    Boolit Bub
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    I took the molds out, scrubbed them down with hot water and soap. They cast wrinkle free. There are still pinch marks on the seam but I'll learn to live with that. I did add a second to the sprue cool, setting it to 5 seconds and mold cool is 3 seconds for my 9mm 124gr pouring at 700 degrees F for 550ms.

    One thing I did notice is the lead pour changes quite a bit as the pot empties.

    Another thing, the machine starts slamming harder as the mold heats up.

    I also found out the top bullet sticks in the mold from time to time, not because it's stuck in the mold but because the sprue plate doesn't open all the way and clear the bullet. I'm thinking of grinding off a small amount of the sprue plate so it clears the mold hole when open. Does anyone think this is a good or bad idea?

    I'm having fun getting this to work and can't wait til it's running like it should.

  11. #11
    Boolit Mold
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    I clean my moulds with carburator cleaner.I pour at around 700*F.My MC is rigged with a 4'' drop tube so that I can direct my bullets either in a steel 5 gal pail or in a 5 gal plastic pail filled with water.I simply let my 35 to 50 first bullets get in the reject steel pail and after I've checked that the bullets come out perfectly formed,I switch the drop tube in the water pail.
    When I'm done with the mould,it is WD40 time sprayed generously everywhere,put in a plastic bag(of course after it has cooled down)with some dissecant.

  12. #12
    Quote Originally Posted by ReloaderFred View Post
    Mark2215,

    The line you're seeing is from the molds separating. One side is probably turning slightly as it opens and causes what looks like a second seam line. Those will go away on the bearing surface when the bullets are sized and lubed, but will still be visible on the ogive and nose. I haven't found them to be a problem, especially with handgun bullets.

    One thing you might do is wait a few seconds longer before opening the molds. As the alloy cools, it usually drops from the mold more easily.

    Hope this helps.

    Fred
    those lines have been bothering me for so long. thanks for the info!

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Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check