.308 too large!!!

[iwottopq]

Hello to all.
Yesterday I melted some boolits in .308 with a Lee aluminum single cavity mould.
When I tried to insert the GC (Pat Marlin GC Maker and litho sheet) it was a bit hard to apply.
Despite all I tried to resize by a .309 Lee sizer but it was so hard to pass that I interrupted the work. I measured the boolits as cast and it was about .313 - .315.
The alloy was 750 grams of WW and 250 grams of print characters.
In the previous cast the boolits were perfect and its was .310, max .311.
I do not understand why now the boolits are so large!!!
Perhaps too print characters?
Please help.
Thanks in advance.
Nino

[I'll Make Mine]

If the same mold has cast .310-.311 boolits in the past, and now is producing .313-.315, I'd look to be sure the mold is closing completely. A bur or piece of lead flash on the mating surface could easily add four thousandths on one dimension (creating an out of round boolit).

Failing that, is this the same alloy you used previously? Different alloys can cast to different sizes because they shrink more or less as they solidify; the additional tin and antimony in the type metal could be causing the size difference (I don't recall which alloys cast larger, but I'm sure there's a table somewhere). Different mold temperature can also affect this (a hotter mold will cast larger), though I wouldn't think it would make this much difference in a bullet this size -- I'd expect no more than .001" from the coldest mold that will cast well, to the hottest, in this diameter.

[Wayne Smith]

Congratulations on your English!

You have a very tin/antimony rich alloy. How fast do you want to send these downrange? What cartridge?

Yes, too much of the print characters (Linotype) and you probably ought to use twice as much of the wheel weights. If this is too soft for your desired velocity water drop them or oven temper them.

[Bomberman]

If the same mold has cast .310-.311 boolits in the past, and now is producing .313-.315, I'd look to be sure the mold is closing completely. A bur or piece of lead flash on the mating surface could easily add four thousandths on one dimension (creating an out of round boolit).



I've had this happen with my Lee mold...you have to be very attentive to make sure it closes properly.

[Jim]

I've had this happen with my Lee mold...you have to be very attentive to make sure it closes properly.

I have developed a habit of quickly flipping the mold over after I close it to make sure there's not a crack showing between the blocks. Every once in a great while, I see one, tap it lightly with my stick, it closes properly and I go back to it. The Lees are economical and great starter molds, but they are not the best in the world for a good, solid close.

[iwottopq]

Hello to all.
I reply to your messages one by one:

For I'll Make Main:- I am sure that the mould is perfectly closed and first to drop the alloy in it I beat a little tap on the back side of the mould to be sure that it is perferctly closed. I dont see light between the two pieces of the mould. Also, I remember that a alloy with plus or minor amount of tin (or was antimony???) give a plus or minor diameter of the boolits but also I dont remember if is plus tin or plus antimony. I read this, perhaps, in a Lee catalog.

For Wayne Smith:- Thanks for your congratulations for my English. I learned it at the school and at the radio becouse I am also a radioamateur, my call is IW8PQ. Also I think that my alloy is very rich of tin/antimony but I dont think that this can be the cause of boolits too large. I thinks that too much tin or antimony can enlarge the diameter by maximum .001 or .002 not .006 from the hopped diameter!!! Also the boolit too large was already dropped in water...

For Bomberman:- See my reply to I'll Make Mine. Furthermore this is not the first aluminium Lee mould. I have other three mouds from Lee and those works very well.

For Jim:- Also for you, please see my reply to I'll Make Mine.

To all:- Thanks for your help. Now I try to made a alloy with less Linotype and/or to leave to cool a little more the mould so the boolit can to shrink.

Thanks again FRIENDS.
Ciao
Nino

[wallenba]

After squaring my mold halves on the flat part of my tapping stick, I squeeze the handles gently, while gently tapping the edges of the bottom of the mold on both sides. I can actually feel the mold closing more. I know that we are not supposed to tap the mold itself, but I'm not using that much force. I only have one or two Lee molds where I have to do this. It solved my problem with that.

CAUTION: Non PC comment below

Lee molds have 'personalities', some are a bit like women. Each has something it likes or dislikes, and if you want to get along with it, it's up to you to figure it out.

[nanuk]

sounds to me like something is holding the mould slightly apart

that you cannot see some light means little during casting.

try again, same alloy, inspect the mould VERY closely, and only make a few and use a nice flat board to set the mould down on to close to help alignment. Measure them.

if still grossly oversize, use a magnifying glass to inspect the mould again. I expect you will find something

that is my guess

[454PB]

It also helps to apply a little lube to the boolits before sizing. I use the same lube I use for case sizing......leather waterproofing.

[grouch]

I have a number of Lee single cavity molds, and have had a similar problem with two of them. They started producing boolits several thou too big and out of round. There was no visible stopping them from closing. It turned out that there was a splash of lead between the blocks, but try as I might, I couldn't see it. Maybe you have the same problem.
Grouch

[wallenba]

Also I have found, under magnification, burrs around the alignment pins where the vertical 'v' portions of the mold come together. Pick it out wit a sharp dental pick.

[GT27]

For me if you are holding the mold straight up(vertical) when you close it makes the blocks seat together more positive in their alignment,try it, and see for yourself!Lee recommends that you do it this way! GT27

[Larry Gibson]

The alloy was 750 grams of WW and 250 grams of print characters.

As mentioned that alloy is very rich in antimony and tin (assuming Italian WWs are of the same composition as American WWs?) causing the bullets to cast out at max diameter for the mould and being hard to size.

However, you mention a previous casting session gave smaller diameter bullets. Was the alloy the same for the smaller bullets?

If it was the same and you want to keep using it then you changed something. Make sure you have lubed the mould alignment ribs and are holding the mould closed.

If the larger bullets were from a different alloy than the smaller bullets then consider a different alloy or going back to the previous alloy. The percentage of antimony is very high in that alloy mentioned.

For a different alloy I would suggest finding some tin and lead. You can get a very, very good alloy by mixing 2% tin with the COWWs and letting the cast bullets air cool and age (harden) for 7 - 10 days before use. The BHN will be in the14 - 17 range, most likely (if good WWs are used) around 16 - 17 BHN. This makes a very good alloy similar to Lyman's #2 and it casts very well at or slightly above the moulds nominal diameter. It also is softer and will size easier.

An alloy of the 70 percent print characters and 30 percent pure lead would also be a good one. You can adjust the hardness by adding or subtracting the percentage of lead used.

Also make sure you are lubing the bullets before sizing in the Lee sizers.

Larry Gibson

[iwottopq]

Hello to all.
Today I melted a about one kilogram of alloy. The composition was 750 grams of lead and 150 grams of print characters and the boolits hardness through the Lee .309 sizer was perfect.
Evidently the previous time I was wrong the weight of the components. I dont know the hardness of the boolits but I try they at the range within 2 weeks.
Now thanks to all for your help.
You are all my friends.
Ciao
Nino

[runfiverun]

excellent.
and thank's for the follow-up.