How do I make a mold cast smaller?

[happy7]

I'm looking for ideas here. I have an old mold that casts about 7 thousands too large. It is a bit much for sizing down. I have thought of mold release and casting hot. I don't really want to change the alloy. And I did check to make sure the mold closes properly.

[Doby45]

Size in steps.

[Bullshop]

If its a 7mm (I hope I hope) sell it to me and buy a new one.

[Von Gruff]

If its a 7mm (I hope I hope) sell it to me and buy a new one.

Still looking for solutions for your carbine?

Von Gruff.

[plainsman456]

The only thing I have done along those lines is add some lino to the mix.

[mooman76]

If its a 7mm (I hope I hope) sell it to me and buy a new one.

How much bigger are you looking for?

[geargnasher]

Reverse-beagle it (sand the blocks) or lube/size it down .001", then push-through in several steps. The lube will keep the grooves open by hydraulic pressure.

Gear

[cbrick]

I have an old mold that casts about 7 thousands too large.


The only thing I have done along those lines is add some lino to the mix.

Hhmmm . . . Its casting too large so you add lino?

Lino, spelled "antimony" will make it cast LARGER.

Rick

[Moonie]

cbrick, you really REALLY need to change your avatar pic, making me want to buy a really large revolver lol.

[cbrick]

Is 45 Colt a really large revolver cartridge?

That's the MP 45 Caliber, clone of the RCBS 270 gr SAA.

Rick

[Doby45]

That boolit just LOOKS like it goes in a gun with a 3" bore. Thats all. ;)

[cbrick]

Really? How does this one look?

[475BH]

Really? How does this one look?

According to my measurements, that would be a 1-1/4 bore.
Ofcourse your monitor may vary from mine.

[Doby45]

Really? How does this one look?

One word, WARHEAD!!

[pdawg_shooter]

I size .311 to .3015 and .459 to .451 in a single pass through a push through die all the time. No problem.

[geargnasher]

Really? How does this one look?

....like it was cut with a dull-a$$ed cherry to me! :kidding:

Lemme guess, .224" around 45 grains?

Gear

[cbrick]

Lemme guess, .224" around 45 grains? Gear

Dang, knew I should have changed the file name of the pic.

Rick

[shotman]

its rough for sure was that a 2 piece boolit

[Centaur 1]

its rough for sure was that a 2 piece boolit

Just place some aluminum foil between the mold blocks and the boolit should break in half when it hits. Probably work great for rabbits and squirrels if it doesn't spin apart while in the air. :bigsmyl2:

[BulletGeek]

happy, you can get a couple thousands off the siz (in one direction, anyway) by lapping the mold block faces with a good flat stone, or with a piece of auto body sandpaper (600 grit or finer) laid on a good flat surface (a table saw table, or a piece of plate glass). Wet sand with a little light oil.

To do both halves of the mold, you'll have to remove the alignment pins. Try to do both sides equally so the shape of your bullet doesn't get too funky. When you've cut down both sides to where you want them, the resulting bullet from the modified mold will still require sizing, but it will be much easier to size to the dimensions you need.