Rotometal lead.

[Kurt]

This year I ordered 300# of lead from R-M and mixed it into 1/16 alloy for the .44's and .45-90. I haven't shot any recovery bullets out of the .45-90 so I shot a bunch using the .45-90 with 83 gr of 2F OE and I used a PP bullet patched a halve thousand over bore diameter I normally do. I went out with my metal detector looking for some before I cast to many to see how they look. What I found bothered me. I found very shallow land cuts and a few wasp waist bullets. Slight but they where there. Noses where very good with very slight setback for the whole bullet like I find using antimony in the alloy.
This is very unusual to find shallow land cuts with using 83 gr of 2F.
When I saw this I had about 70 left from last year with 1/16 T/L from R-M and shot 20 in the snow so I can compare the two. These had full engraving with a good nose. Couldn't get a better combination with lead tin.
Have any of you that just got a new supply of lead noticed any weight change or hardness ?? These pigs where listed as 99.9% pure. It sure does not show this from the recovered bullets. I wonder if they reclaimed a bunch of lead shot that has antimony in it and called it 99.9%

My effort casting is not in vain because I can patch it tighteror use them for the .44-90 bn that has a heavy powder charge, but if I would use it for the .45-70 patched to bore I would not get full rotation if they had just slight gas bypass.

[Don McDowell]

I gave up on Roto, never seemed the alloy from them was the same twice. I get most of mine from John Walters now.

[Kurt]

I used to get my lead and tin from John. He would never take a card over the phone, he just said I will put the bill in the box and you send me a check. I had John's number pinned to the wall but I lost it somehow. I don't think John has a website, or didn't have one.
But your right John always sent me good stuff.

[Don McDowell]

That's just the way John operates, no web site, just send him an email asking for lead and or wads, pretty quick it'll show up with an invoice inside. He also delivers a bunch of alloy to folks at Raton. Met him there last year , one heck of a nice guy.

[Gunlaker]

That's not encouraging. I switched to Rotometals a year or so ago because my local supplier sold me lead that was supposedly 99.99% pure, but definitely had a little antimony in it.

So far my bullet weights are pretty consistent, but I have never tried any hardness testing.

Chris.

[Kurt]

Chris what makes it worse is adding the amount of tin to what you think is pure lead makes it even harder. Just a small % antimony will through out of the park you want to be in.
I don't have a lead tester I can trust. I can only use it for reference comparison. So I really cant say that the Roto Metal is not as advertised.

[Gussy]

A lead tester will only show hardness. You still won't know the exact mix or what's in it. Could be a touch of antimony hiding in there. Pure lead is hard to test.

[Fogman01]

I was about to buy my first batch of lead for casting - plan to do that soon - good to read this about RM. I was wondering how pure their stuff really was. Does anyone have John Walters number so I can try him?

[Lumpy Grits]

Try 405-799-0376
LG

[Martini2]

snip.......
Have any of you that just got a new supply of lead noticed any weight change or hardness ?? These pigs where listed as 99.9% pure. It sure does not show this from the recovered bullets. I wonder if they reclaimed a bunch of lead shot that has antimony in it and called it 99.9% snip...

Kurt and all, attached is a note written to friends that cast. Is it possible the supposed "pure" metals can have trace elements. It may help to compare as cast diameter of new mix with your known alloy. Also just squeezing one bullet cast of new VS one of known alloy crossed in vice will 1) show hardness comparison 2) show any micro cracks hinting of Arsenic presents. Hope this helps

One item that has surfaced is topic of casting Alloys and varying amount of hardening mixtures. I lifted the following from an issue of American Rifleman that is so old the print copy has 98 pages. A key component in hardening alloys is with Antimony. One of the sources for Antimony is Shotgun pellets. Particularly the Lawrence brand of magnum shot contains higher antimony that may be blended in our casting pots. CAUTION however is noted because along with Antimony the shot alloy also may contain Arsenic. The Arsenic is used in shot manufacture as it effects the surface tension of molten alloy. The positive effect of arsenic causes the droplets of metal to form more perfect spheres while falling through air. Arsenic in vary trace amounts assists Antimony in hardening the cast pieces. On the negative side, strings of high Arsenic result in cracking. Micro cracks are caused by shrinkage porosity in bullets cast entirely of lead shot. Arsenic is of course hazardous to health. These facts and more here are attributed to Col. Harrison’s published books. “Arsenic is also a benefit in cast bullets where it improves the hardness of antimonial alloys, and optimum concentration range for arsenic of 0.1 to 0.15%.” “At these levels arsenic increases the as cast hardness of most antimonial leads and it also provides the capability to heat treat alloys like wheel weight metal to 30BHN or more.”
I’m not sure of the need for harder alloys in our BPCR loads especially if one expects the bullets to expand to help seal the bore. However, the following might help our understanding of what alloy components will do to as-cast mold diameters. “A little-known fact about elemental Arsenic is that it contracts 10% on solidification compared to 3.4% for lead, 2.8% for TIN and 0.8% for antimony”.
There were ample cautions about melting lead shot. The presents of Arsenic adds smell of Garlic and is of course determinantal to health. Adding shot in small amounts may best be taken on OUTSIDE in open air. Once melted in low concentration the normal exhaust precautions should be followed and work.
Setting the alloy with Arsenic aside my eye caught the fact that Antimonial alloys shrink LESS on solidification. Therefore, if we wish to cast bullets that are maximum for mold diameter the alloy should contain amounts of Antimony. Unfortunately melting of pure Antimony is tough due to its higher melting point. Casting hard alloy bullets may be unproductive unless as-cast diameter is properly greater than bore I.D. Casting hard alloys requires more detail to bullet to bore fit. They also require higher forces to put through lube dies. I’m not sure any of you will find these details of value. The “discovery” is worth sharing if not only as background for our casting ops.

best regards RobertB