low temp = small boolits ?

[superior]

I just got my Lee c312-185-1r last night and I thought I'd cast up a sample batch.
My melt wasn't hot enough to produce wrinkle-free boolits and almost all were rejects. After the rejects cooled I measured them and they dropped smaller than my Lee CTL312-160-2r's. The 160's won't fit into the muzzle but the 185 reject boolit will fit right up to the front driving band. Could a Hotter temperature make for a larger diameter boolit? Or am I doomed with a 185 that drops undersize?

[docone31]

You have a Lee mold. If you want good castings, you have to keep the mold hot!
I ran into that many times with my molds. I have only Lee. I really like them. Once you get your mold hot enough, it actually gets boring casting.
I have the same mold you are questioning. I did end up casting through a nut, 1/4-20 and coating it with Clover Lapping compound and turning it with a wrench.
Problem solved.
Could be from a variety of reasons, cutting lube impregnated in the pores of the mold, too cool, or just not broken in.
I use that mold for paper patching my Enfield Smelly. A winning combination for me.
When I heat my mold, I set it in my melt. When the lead does not freeze on the outside of the mold, I cast. If the sprue does not freeze, I know it is too hot. If it freezes too quickly, I wait a bit to dump the castings.
You will get there, crank up the heat.

[superior]

I was hoping you would reply, docone31. Are you saying that once I get it right, I might make larger diameter boolits?

[docone31]

Once you dial it in, it will become your favourite. For my .30s I went with the 180gn counterpart. They are both my go tos for both my .30s, and .303.
Crank that puppy up!
I use 8 or 9 on my pot, and really heat that mold up.

[R.C. Hatter]

You don't say what alloy you were trying to cast with. Alloy type has some effect on the "as cast" diameter of the boolit. For example, a soft alloy of say, 1-20 will cast much smaller than linotype. Generally speaking, it's possible to obtain a certain diameter, by choosing the appropriate alloy. You may wish to try it before you go to polishing the offending mould.

[superior]

This time my alloy was similar to my tl-312-160's alloy of ww however this time the cast iron pot was getting towards the low side and I added a 6 inch strip of stick-on's to about 10 pounds of ww.

[superior]

I'm aware now that alloy affects size but can temperature affect size?

[docone31]

I am not sure.
I paper patch that casting, so I am not really that picky on finished size. I down size it to .308. The .304 neck gives me what I need for bore, and I wrap to .314 for groove.
I would have to imagine, temp would produce shrinkage in the mold which would reduce final drop size.
Rather than make mystery metal, I alloy, ingot, then realloy blending my know metals to produce the blend that works for me. I also have zinc in my melt. So far, it has helped in what I do. Not much, but some. I also added some, I believe Babbit material. I get some really hard castings. To date, I have not recovered any from the berm. They seem to go really deep.
I do not hunt with them so expansion is not an issue. Bowling pins explode when they hit them.
There are so many factors in getting quality castings. Heat, alloy, and mold size. Lapping molds like I do, does not really enlarge them, just cleans them up. I use one casting to do both cavities.
So far, so good.

[oneokie]

I'm aware now that alloy affects size but can temperature affect size?

Yes, temp can affect size. Higher temp of the melt equals more expansion of the liquid alloy. Thus, when the alloy solidifies, it will have more shrinkage. Most noticeable with the softer alloys.

[superior]

So let me get this straight. Higher temp = smaller boolits? I'm sooooooo cunfused lol.