New Lee .401 mold dropping .399-.400?

[Xfire68]

I am new to casting handgun boolits but, have done a number of shotgun slugs. I am using close to pure lead I believe as it came from Dental foils and water pipe.

The mold is a 175g TC 2 hole.

I don't have a hardness tool to test.

The other new mold I have is a Lee .356 and it is dropping .356.

Mold was brought up to temp. I smoked both molds as well as degreased them before I tried my first run (Not in that order).

I will be shooting these from a Glock 20 10mm with a Lone Wolf 10mm to .40 conversion barrel but, I don't have the barrel yet to slug it.

My CZ 75b slugged at .356.

Any ideas of what I should be looking at or trying? Or is this mold under sized?

[popper]

Clean out the smoke. Add some antimony. Don't get the mould real hot.

[khmer6]

They work nicely in my g20 :thumbup::thumbup::thumbup:

[Xfire68]

I ran another batch as some on chat suggested that the mold was not hot enough. I got the same results. .398-.400.

The 9mm .356 mold drops .356-.356.5 every time??

Both caliber boolits are beautiful, fully filled out, smooth and shiny?

They all also said as stated above that I need to add some tin to the mix or trade the pure lead for WW's..

[khmer6]

Lee can be hit or miss. Try not to use kung fu grip on the handles. Maybe even beagle tape

[SWANEEDB]

Scrub out the mold again with HOT (Dawn) soapy water to remove the smoke residue, clean is the key to a good bullet, if you feel you need the smoke use a Bic lighter and lightly hit it with its smoke, bet you'll get a .400 or .401 (maybe)

[leadman]

If your alloy is close to pure this could be your problem. I have several Lee 9mm molds and they all drop closer to .358".
A 40 and a 9mm should have a harder alloy for best results. Water quenched wheel-weight alloy works well.
Another option is buying some linotype off the Selling & Swapping here and mix it with your present alloy. About #3 of Lino to #19 of your alloy should work fine.

[steve4102]

I have the same problem.
I have three(3) older style 2 cavity Lee 40/10MM moulds and they all drop .402 or larger. I size to .402.

I recently purchased a New(new design) 40/10mm 6 cavity mould, 175gr TC. It drops bullets at .400 with an occasional .401. I have tried everything from COWW, to lead, to COWW with Monotype, to straight Monotype and they all drop less that .401.

I removed the handles and it is now a nice paper weight.

[Xfire68]

Clean out the smoke. Add some antimony. Don't get the mould real hot.

I removed the smoke and the boolits look even better but still .398-.400 in size.

I will see if someone wants to trade some pure lead for WW's?

Man they are beautiful looking pills! SOB! :)

[justingrosche]

Pure lead will cast the smallest and heaviest for bullet alloy. Add 50% wheel weights or 25% linotype and your problem will go away.

[Xfire68]

Yeah they are weighing in at 180-181g and the .356's should be 125g are 128g.

[spfd1903]

Are you measuring the diameter with a micrometer?

[Xfire68]

Are you measuring the diameter with a micrometer?

No calipers.

I know they are undersized not only from the measurements I took but also that they drop right through the sizing die.

[leadman]

When you get a good alloy you may still have to play with the mold and alloy temperature to get it up to spec. Look on the Selling & Swapping threads here for alloy. Or buy some commercial cast and melt them down just for this issue. If you are using a bottom pour get everything up to temp and then fill the mold with it tight to the spout. If it is a fill-out problem this should make it fill-out, then measure it.
I have noticed that the 6 or so new Lee molds I have bought in the last couple of months that they like the temperature around 700 degrees brfore they cast good boolits. Twenty-five degrees can change the way they cast so play with the temperature. The molds go from not filled out, hard to release from the mold to cut the sprue by hand and open the mold and the boolits fall out.
If that fails call Andy Lee at 262-673-3075. Real nice guy and will probably want you to send the mold in for inspection. Sometimes if you ask they will reimburse for shipping.
Hope Lee is not trending back to undersized molds again.

[Xfire68]

I made a deal to trade some Jacketed bullets for 55lbs of WW alloy. Hope it does the trick as I will have over 100lbs and 2 cavity molds! LOL :cbpour:

[spfd1903]

I cast the tumble lube 175's in a six cavity mold. Cast with a 10:1 alloy and kept the temperature at 750 deg. Diameter stayed pretty constant at. 401. Shot equally well from Glock 23 and a Hi-point. Experimented with under 700, at 700, and 750 degrees. Latter temperature gave the most consistent diameter.