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Member Joined: 27 Oct 2006 Posts: 161 Location: New Mexico

I've moved a lot of lead in my day (shielding in radiation experiments), and I got tired just thinking about hauling it to the top of that tower!

Slide, I'm beginning to perceive you might be a professional in this matter. If so, I appreciate your correcting my mistakes and possible misconceptions of what I've been given to understand these past years. For my own education and clarification, I'd like to take your critique point by point. Please feel free to correct me if necessary. Thanks.

quote="Slidehammer"]

Joined: 06 Mar 2008 Posts: 596 Location: 17603

This one is 75' tall AND has a 75' shaft underground.

16GG,

I think a good article on lead and lead alloys is in Lyman's Cast Bullet Handbook, Third Edition. "The Metallurgy of Molten Lead Alloys" by Dennis Marshall. In just a few pages there is a wealth of information that gives reference to many of your questions and most of it can be understood by those with general metallurgy/chemistry knowledge I believe. You may even have this book in your library or know someone that has it. Some of your questions I have changed to blue and will attempt to answer...

If so, wouldn't the forming antimony crystals naturally gravitate toward the surface of the pellet or shpere as the molten and more dense lead gravitates toward the center? Wouldn't this process naturally distribute more antimony to the outer parts of the sphere? I think I understand higher amounts of antimony (within limits) provide more hardness overall but that the crystals are not distributed in an exactly uniform way. Is it not true the solidified spheres are therefore a bit softer at their centers and a bit harder on the surface because of this somewhat unequal distribution?

I don't think so. Let me quote from Marshall's article...
"(In lead alloys) tin and antimony, either as individual additives or in combination, literally dissolve in molten lead to form true, stable solutions, just as table salt or sugar will dissolve in water. And, with the exception of oxidation or an electrochemical potential, once the solution has occurred, there is no force, gravitational or otherwise which can separate the constituents."

I've been given to understand the main function of the tin in the alloy is to limit corrosion and surface abrasion as well.

No... The main function for tin in lead alloys I believe is "castability". Being able to better fill a mold with sharp edges possibly even a hollow point. It modifies the alloy's grain structure to accomplish this.

Is it not also true that solid tin is harder and less dense than lead?

Correct.

Does it not also act as a binder to help the antimony crystals formed to remain better distributed in the matrix of the hardened alloy as it cools and hardens into a pellet.

This is the grain structure I mention above. I believe this quality would help in shot. I'm not sure modern shot has much tin in it due to cost. Probably more would help.

I've also been given to understand the gravity and natural surface tension of the liquid (molten) glob in free fall is the main factor in how and why the alloy forms into a sphere as it falls. Both the arsenic and the tin help the process and contribute to the overall roundness of the resulting pellet.

Again, Marshall has a couple of paragraphs in his article why arsenic makes the shot spherical... Interesting chemistry!

Antimony tends to disrupt it a bit as the faster solidifying crystals gravitate to the surface of the still molten matrix.

Tell me where you read this please... I want to see it in the context of the article.

Is it not true that solid antimony is far less dense and significantly harder than lead? Does it not also melt (and therefore harden) at a significantly higher temperature than either lead or tin?

Yes to the first question. Yes to the second question as far as elemental (pure) Sb only.
But lead alloys are simply fascinating!!! A Binary eutectic alloy of lead and antimony (about 11.5% Sb) will melt at 484 degrees F! This while pure lead melts at 621F and antimony at 1167F!!

Okay, but is it any harder or softer than Magnum 7.5 or 8 shot?

I have hardness tested West Coast Magnum 7's, 7 1/2's, and 8's and I believe they are dropped from the same alloy.. Lawrence 7's (actually a 6 1/2) are quite hard as well. That's the only Lawrence shot I have other than an old bag of 2's.

Slidehammer

Joined: 08 Jul 2009 Posts: 6

Mr. Rrusse11

Thank you sir for answering my questions. I will procure a copy of The Lyman 5th Edition as soon as I can.

Just a small observation, I thought that this was a nice website.I am begininng to get the feeling that there are more ego maniacs here than gentlemen with knowledge. I hope that the gentlemen show up and don't get entangled with the other less desireable types.

Again, my thanks for the answer.

jbiss

Joined: 06 Mar 2008 Posts: 596 Location: 17603

jbiss,
You're very welcome.
As far as this website, or any other board on the net, you will find a broad array of people, with at times gnarly attitudes and opinions. Keep your head down, and wear a flak jacket, there IS a great deal of good information, and some wonderfull folk here. As in life however, there will always be those who rub you, and others, the wrong way, don't take it to heart. Very Happy

Cheers,
R*2

Joined: 08 Jul 2009 Posts: 6

Mr. Rrusse11

I am very sure that I neither want to wear a flak jacket or have to keep my head down. I was hoping for better.

These fellows 16Gaugeguy and Slidehammer are more interested in one upsmanship than helping. After watching this little show I will not be returning.

Thank you for your help,

jbiss

Guest

Joined: 09 Jul 2009 Posts: 510 Location: Central CT

Pretty tough crowd here.

Joined: 07 Oct 2008 Posts: 74 Location: MO Ozarks

jbiss - I'll take a swing at it.

Both chilled shot and magnum shot are lead, but have alloying metals (most usually antimony, but other metals have been used in the past). Chilled shot has a smaller amount, usually less than 2%, while magnum shot has a greater amount, usually between 3% and 6%, making it harder. The "dead soft" shot referenced by 16gg would be pure lead, with no alloying metal at all. Please note that I have used the weasel-words usual and usually. The problem with being more definative is that each shot manufacturer has their own formulation and does not bother to place that information on the shot packaging. They just use the rather indefinate terms "chilled" for softer shot and "magnum" for harder shot.

Chilled shot tends to deform more upon firing than does magnum shot, due to set-back forces, choke constriction and barrel scrub. As stated in the previous posts, deformed shot can produce "flyers" that spread the pattern, thus magnum shot will generally pattern tighter with the same choke than chilled shot.

Plated shot (usually nickle or copper) is simply lead shot that has a plating over it. Plated shot can be either chilled or magnum, then plated. Many hunters like plated shot, feeling that it provides better performance on game.

Chilled shot is slightly cheaper than magnum shot, usually by less than $1/25lb bag. Plated shot is more expensive than unplated shot.

You will see any number of opinions regarding the use of chilled versus magnum shot for various uses. Generally I just ignore the noise and use magnum shot for everything, as that is what my local retailer normally carries! I would recommend you do the same for the time being. Once you have some experience at reloading you may wish to try something else.

Don't know if this has answered your questions or not. If you still have specific questions, don't hesitate to ask.

Good luck and welcome to the forum.

Thanks Slide, I appreciate your time and effort here.

Joined: 09 Jul 2009 Posts: 510 Location: Central CT

bcpifish,

I am with you, I don't know why i would want deformed pellets in my pattern. I only shoot Magnum shot.

I hope jbiss reads your post.