Bullets to Small?

[steve4102]

I'm working with my New Lee six cavity 40/10 175gr TC. I'm using straight WW alloy.
They are dropping at about .400 to .401. They just slide through the Lee sizing die without much if any contact. They should be larger, Yes?

Is it the mold or is it my alloy and temp? Is there a way to increase the drop size by using temp or some other technique?

I have air dropped them and water dropped them and they measure the same.

Thanks
Steve

[snuffy]

Straight wheel weight alloy is low in tin content. If you bring that alloy up to around 2% tin, you will cast a larger boolit.

Are your boolits nicely filled out? Sharp crisp corners on the driving bands and the base is sharp and clean? Then addition of some extra tin will result in slightly bigger boolits.

Tin can be bought in the form of lead free solder. Be sure to get 95% tin-5% antimony. A pound roll will set you back about 20 bucks, but not much is needed for a 20# pot of WW.

[Randy C]

[steve4102]

Yes they are filled out nicely and look great. I have a roll of 95/5, I will add a little to the mix and see what happens. How long a piece of solder should I use for a full 20# pot?

[Jim]

If you want to add 2%, you'd need to put about half the (1 lb?) roll in a 20 lb. pot. If my memory serves me correctly, there's 21 ft. on a full roll. Try 4 or 5 ft. to start with and test.

[44man]

I have a lot of doubts that tin will increase size. I use plain WW's, water drop and with a little aging they expand. My .476" boolits will reach .478" with time.
The largest boolits will be at the point they fill perfect. Increase the mold temperature and the boolits will get smaller. The smallest will be frosted. Don't ask, I get tired of explaining.

[44man]

I have a lot of doubts that tin will increase size. I use plain WW's, water drop and with a little aging they expand. My .476" boolits will reach .478" with time.
The largest boolits will be at the point they fill perfect. Increase the mold temperature and the boolits will get smaller. The smallest will be frosted. Don't ask, I get tired of explaining.

[btroj]

In my experience tin won't increase bullet size at all. Adding more antimony could make the bullets larger.

Like 44man mentioned, let em age a week or so, they may grow a bit on their own.

You may just have a mould that casts undersized.

[Larry Gibson]

The addition of the tin will most likely make the bullets larger. The tin combines with the antimony and make's it go better into solution in the lead. The tin also aids in better fill out which means larger bullets. Some batches of COWWs have sufficient tin but most do not. For 20 lbs of COWW alloy add 6.4 ounces of tin. Your bullets are coming out undersized from the low tin content of your alloy. Add the 2% tin, cast at 725 degrees, let the bullets AC and age for 7-10 days and then tell us if it made any difference or not.

Larry Gibson

[snuffy]

The addition of the tin will most likely make the bullets larger. The tin combines with the antimony and make's it go better into solution in the lead. The tin also aids in better fill out which means larger bullets. Some batches of COWWs have sufficient tin but most do not. For 20 lbs of COWW alloy add 6.4 ounces of tin. Your bullets are coming out undersized from the low tin content of your alloy. Add the 2% tin, cast at 725 degrees, let the bullets AC and age for 7-10 days and then tell us if it made any difference or not.

Larry Gibson

Thanks Larry for that confirmation on what I said! I usually stay silent on most questions I see on here, I'm just not sure if what I say is true. BUT when I find the results of my own experiments to be true, I speak up.

I have a very large amount of range lead from an indoor range. It has very little tin in it, But seems to have a lot of antimony. By adding as little as 1% more tin, I see an increase of .001 in a 45 cal boolit. That's right after casting, barely cooled. I suspect if the antimony wasn't present, the tin would do nothing, (but increase fill-out a bit).

I so often see it said that boolit "grow" ,(increase in diameter), as they age. That just don't seem possible. But it's said to happen so often, I guess it does! Time for an experiment. Might as well do a hardness increase test at the same time.

Lee's dimensions from one run of the same mold to another can vary by as much as .003! I all comes from the set-up of the machine at the time they're making another run. Lee uses a lathe boring technique, spinning the mold while a cutter is fed into the cavity. Most molds are cut using a "cherry" that's fed into both cavities in a special vise.

[shadowcaster]

Did you smoke your mold? I personally do not smoke my molds and have heard from others that by doing so can produce slightly smaller boolits. I have not tested the theory myself, but it may be worth a shot. Just my 2 cents..

Shad

[runfiverun]

a little tin just allows the antimonial matrix to break through and give better sharper mold fill out.

the 400-401 diameter and the sizers relationship are a non event, the question is do they fit your barrel.

[steve4102]

a little tin just allows the antimonial matrix to break through and give better sharper mold fill out.

the 400-401 diameter and the sizers relationship are a non event, the question is do they fit your barrel.

Yes and no. They fit my DW 10MM CBOB that slugs at .400 and leading is minor, but not my RIA 10MM. When new, the RIA slugged at .4025, I sent it back to Armscor and the replaced the barrel. This new barrel slugs at .401+ and leading is a major issue with the Lee six cavity bullets.

[Larry Gibson]

Add 2% tin to your WWs and cast at 725 degrees as mentioned.

Larry Gibson

[Larry Gibson]

Snuffy

I also use and have a lot of "range lead" which is also quite high in antimony. It also will cast smaller bullets and give poor fill out in TL bullets especially. I add 20 - 30% lead to dilute the antimony and then add 2% tin. It runs 12 - 14 BHN when AC'd and 18 - 20 BHN when WQ'd. Makes good bullets either way.

Larry Gibson

[steve4102]

I cast a few bullets today. I used three different Lee 40/10 molds. One six cavity and two , two cavity. One of the two cavity was a Tumble lube type.
I cast 12 of each with straight WW alloy. Half were air cooled and half were water dropped, 700*

Then I added a foot of Solder to the pot and cast 12 more of each.

Then I added 1/2 lb of Monotype to the pot and cast 12 more of each.

I measured all the bullets and recorded each.

Now I am going to let them sit and see what happens.

So far it appears that my six cavity mold is running smaller than the other two.

[williamwaco]

I use that same bullet and it falls at about .401 using clip on wheel weights.
I run it through a .401 sizer and it shoots very good.