can't get the same results

[jacob7]

A question I can't seem to figure out. I bought a bullet mould from Buffalo Arms and the bullet he sent me from that mould was perfect. My problem is I can't get the same results. His bullets are 535g and .459 mine is 529g to 530 g and .458. He uses 20/1 so am I. He pours at 700 degrees and I did it at that temp. too. Any suggestions on getting the same numbers? I don't mind the weight as much but I want the .459. Also who makes a good large hand pour ladle? Thanks.

[BABore]

Likely the mold was not hot enough. That doesn't mean you need the alloy hotter. It means you need to preheat he mold and cast at a pace fast enough to maintain that temperature.

Do a search for a 1 lb Rowell bottom pour ladle. I got mine from the Antimony Man, but they are also available from Advanced Car Movers. They're the guys who make them. IIRC, RotoMetals, a sponser here, also carries them.

[Doc Highwall]

jacob7, are both of the bullets from a certified 20:1 alloy?

[cbrick]

Diddo BABore, hotter mold, cast a bit faster, no need to turn the pot temp up and oxidize the tin.

I recommend Roto Metals for your ladle. They are a sponsor here and help support this site.

Rowell Ladles (http://www.rotometals.com/Ladles-for-Casting-s/8.htm)

Rowell #1 is the one that will work best for you, you don't really need bigger than that unless your using gang moulds.

Rick

[jacob7]

My lead is from John Walters- Wad and lead man- Theirs is there own. I don't know if they are certified. Jim from Buffalo says adding more tin would probably help.

[44man]

Not much you can do to make a .458" to .459" with any alloy close to 20 to 1. Tin will not expand the boolit, only antimony.
Sounds like a BPCR with the alloy.
Maybe the mold is just too small.

[Doc Highwall]

jacob7, the way I am interpreting this is, you bought a mould and it had a bullet in it that was cast of 20:1 alloy and you weighed and measured it, and compared it against a bullet from your 20:1 alloy.

[jacob7]

Yes that is true. I can't get mine to match his. I talked to Jim personally and we talked about it.

[Doc Highwall]

jacob7, is the bullet they sent with the mould round or egg shaped? I was thinking if the mould handles were not squeezed as hard on the bullet that they sent you it would measure larger opposite the seams making it larger on that dimension and smaller on the seam, kind of like beagling. And that would account for the diameter and weight difference.

[Chicken Thief]

I think temp is the culprit here.

I recently bought a 459-500 3R Lee mould from another forum member and "all" he could get it to cast was 457 and that with WW's. I use pure lead and when the mould is smoking hot it will cast 460-460½. The sprue takes 12-15 secs to solidify, that's how hot i run the mould.

[Bret4207]

If it's the alloy, melting his boolits down and casting with them ion your mould will show that. If it's the mould, not much you can do except add some antimony. You're pretty rich in tin already.

Not every mould will cast the same size as another of the same design, in fact it's rather rare to get a mould/alloy combo that will duplicate someone elses results dead on.

[44man]

A mold must be hot but get it too hot and it shrinks more inside because it is not a hole in one piece of metal. A hole will expand.
Every time I make a mold and it casts too small I put the cherry back in when the mold is hot and remove more metal.
I tried freezing the mold but that didn't work in the end. Get it hot and see just how much more it will be cut.
Chances are the boolit that came with the mold was cast at a COOLER temperature.

[Bass Ackward]

Yep, it's either hotter or cooler. Ain't too many other options.

Cept I wouldn't concern myself using 20-1 cause it's going to expand out until it is restrained by steel anyway. Think of it as ideal fit if you can center it up right. And that is best done by design, not hardness or diameter anyway.

The only reason to go big is cause you didn't slug and get the design right in the first place or have a really worn piece.

Have ya shot any yet? Cause it will only make a difference if it does.

[Rocky Raab]

Forgive me if this seems like an odd or stupid question, but when you said "the bullet he sent me from that mould" are you sure it is a bullet from that individual mould, or is it a bullet sample cast from that model number mould?

Because the possibilities are obvious.

[44man]

Forgive me if this seems like an odd or stupid question, but when you said "the bullet he sent me from that mould" are you sure it is a bullet from that individual mould, or is it a bullet sample cast from that model number mould?

Because the possibilities are obvious.
Good call unless the boolit was still in the mold. If it was in the mold, I bet it was cast COOLER.

[cbrick]

44man is in all probability right.

I have often wondered about people that post that they crank up the heat as high as it will go, aside from the harm done to the tin in the alloy, what size is this mold now casting at?

When the mold material gets hot it expands (most everything does) and it expands in every direction. That means that the hole in the middle of the blocks (the cavities) shrinks, gets smaller and it will produce a smaller diameter bullet.

Rick

[44man]

44man is in all probability right.

I have often wondered about people that post that they crank up the heat as high as it will go, aside from the harm done to the tin in the alloy, what size is this mold now casting at?

When the mold material gets hot it expands (most everything does) and it expands in every direction. That means that the hole in the middle of the blocks (the cavities) shrinks, gets smaller and it will produce a smaller diameter bullet.

Rick
Right on my friend! [smilie=s: So hard to explain.
There lies the problem because pure, almost pure or lead and tin does need more heat for a full boolit. A few degrees?

[prs]

My education continues.

prs

[Rocky Raab]

Not arguing in the slightest, but what I don't understand is this: if the cavity of a mould gets smaller when the mould heats up, why do we heat frozen nuts to loosen them? And why do we heat interference fit parts so the hole expands enough to admit the second part, then cools to grip it tight?

[Bret4207]

I'm with Rocky in wondering if there's a rule of that. I know when you heat a stuck nut there's some crush factor as well as expansion there. I think I saw something on this in Machinerys Handbook or somewhere but it wasn't in laymans terms.

[jacob7]

Yes the bullet is round being only.001 off. I also put the bullet back in the mould and it shut perfectly to me. I had to tap it out just like I do when I pour.

[leadman]

Having worked on heavy equipment for over 40 years when you want to put a shaft in a hole, heat the hole, freeze the shaft. Did it all the time for press fit parts, like a bearing race on a shaft.

[jacob7]

No it wasn't in the mould but came with the mould. He said it was cast from the mould.

[Bullwolf]

When I worked as a mechanic for an Italian performance shop, I did a lot of head work for Pantera's.

Consequently I ended up installing new valve seats in quite a few 4 barrel 351 Cleveland heads.

First I would put the valve seats in a cooler, along with some dry ice.

Then I would slowly warm up the engine heads, using a torch.

Lastly, I would press the cold (smaller) valve seats into the warm (larger) engine heads.

I had not thought about doing that in a while, but I remembered it after reading this thread.


When the mold material gets hot it expands (most everything does) and it expands in every direction. That means that the hole in the middle of the blocks (the cavities) shrinks, gets smaller and it will produce a smaller diameter bullet.

Rick

Nicely worded example there Rick, with the expanding, and contracting metal.


- Bullwolf