Are all 9 BNH alloys equal?

[rr2241tx]

Here's why I ask: Lyman lists straight WW and 30:1 both as BNH 9. I just happen to have about a year's supply of WW ingots and enough bar solder to make up the batch with equivalent tin content to make .40-65 Win boolits for silhouettes. What do you think?

[sqlbullet]

No.

The density difference between tin and antimony at room temp is about 15%. And, looking at a binary phase diagram of lead-tin and a ternary phase slice for lead-tin-antimony presents a very different picture of what is going on as well. They will have very different stress/strain readings due to differences in tensile strength.

In real world terms, the 30:1 will be much more ductile than WW alloy. For 40-65 silhouettes, I would probably stick with 30:1 and save the WW for pistol rounds. Or trade it here for more pure lead or tin.

[Larry Gibson]

sqlbullet gives the answer......+1.

Larry Gibson

[44man]

Here's why I ask: Lyman lists straight WW and 30:1 both as BNH 9. I just happen to have about a year's supply of WW ingots and enough bar solder to make up the batch with equivalent tin content to make .40-65 Win boolits for silhouettes. What do you think?
No, BHN gives no indication of the metals in an alloy. You can't make 30 to 1 out of WW's. Adding tin is usually a waste with WW's too. It will neither harden or soften.
The best would be to add pure lead to the WW's or shoot them as is.
By the way, my WW metal is 13 BHN.

[williamwaco]

Lyman lists straight WW and 30:1 both as BNH 9.



I was shocked by this statement so I looked it up. It is correct. Lyman does list the BNH of wheel weights as BNH 9.

I am surprised by that assertion. I do not believe it is correct. I have been casting with wheel weights since the 1950's.

When I first started using them, they were so hard they would sometimes shatter when you hit them with a hammer. That was our "hardness tester" If they shattered or just broke, we cut them 50/50 with scrap lead.

Over the years, they have been getting steadily softer. Most reverences I have seen the past few years list 12 BNH to 15 BNH. Even Glen Fryxel lists 12. See:

http://www.lasc.us/Fryxell_Book_Chapter_3_alloySelectionMetallurgy.ht m

I am a devout hoarder of wheel weights. I have almost 1000 pounds of standard ww ingots in my garage. The BNH range of those ingots is 12 to 14. It would not be accurate to average it to 13 because most of them are in the range of 14. I would report that the BNH of clip on wheel weights is "around" 14.

Since stick-ons appear to be nearly pure lead, I always segregate them.


.

[Char-Gar]

Here's why I ask: Lyman lists straight WW and 30:1 both as BNH 9. I just happen to have about a year's supply of WW ingots and enough bar solder to make up the batch with equivalent tin content to make .40-65 Win boolits for silhouettes. What do you think?

Good to hear from San Marcos, one of my favorite places. My GGGrandfather William D. Pitts settled here in 1844. Did you guys every get a public shooting range? I have not followed that in a while.

The answer to your questions is there are a number of ways to get an alloy of Bh 9, and alloys wont act the same way out of a rifle. I don't know if you are talking black powder or smokeless powder loads.

I am not as certain, as others seem to be, that WW cut with solder to give an alloy of Bh. 9 won't do just fine for you. I have long ago, learned that theory just goes so far. What happens on the target is what counts and often we are surprised when our theories are knocked into a cocked hat by performance at the target.

My counsel to you is to try it and find out. If you have a good supply of WW and solder, give it a go and find out. I suspect you will be pleased, but who knows.

[Char-Gar]

I was shocked by this statement so I looked it up. It is correct. Lyman does list the BNH of wheel weights as BNH 9.

I am surprised by that assertion. I do not believe it is correct. I have been casting with wheel weights since the 1950's.

When I first started using them, they were so hard they would sometimes shatter when you hit them with a hammer. That was our "hardness tester" If they shattered or just broke, we cut them 50/50 with scrap lead.

Over the years, they have been getting steadily softer. Most reverences I have seen the past few years list 12 BNH to 15 BNH. Even Glen Fryxel lists 12. See:

http://www.lasc.us/Fryxell_Book_Chapter_3_alloySelectionMetallurgy.ht m

I am a devout hoarder of wheel weights. I have almost 1000 pounds of standard ww ingots in my garage. The BNH range of those ingots is 12 to 14. It would not be accurate to average it to 13 because most of them are in the range of 14. I would report that the BNH of clip on wheel weights is "around" 14.

Since stick-ons appear to be nearly pure lead, I always segregate them.


.

My current batch of blended and reblended WW give me about Bh. 11

[montana_charlie]

I was shocked by this statement so I looked it up.
Me too, and I have a reason for disbelief that seems valid to me.

Dan Theodore (a perfectionist in experimentation) did a year-long test of bullet alloys to see how hardness changed over time. Because he is deep into BPCR, most of his alloys were lead/tin mixes.

Because he was careful to establish a reliable technique for testing hardness ... and used two testers to check each other ... he became convinced that the commonly found 'hardness table' seen everywhere is wrong.

That table says:
Lead = 5
Tin = 7
1 to 40 = 8
1 to 30 = 9
1 to 20 = 10
1 to 10 = 11

Dan T.'s testing showed:
Lead: 4.5
Tin: 5.0
30-1: 6.6
20-1: 7.8
16-1: 8.2 for a year, then softened to 7.39
Lyman # 2: 15.4

He believes the reason for the discrepancy is that 'a reading' was taken incorrectly many years ago, and the others are projections from that single faulty one. Because they have been around so long, nobody has seen fit to question them, up to now.

He bases part of his theory on the fact that Lyman #2 is listed as 15 BHN. Lyman developed the alloy in 'modern times' and tested it for hardness. Their results were added to the 'table' as reported ... but none of the others can be traced back to any particular source.

CM

[Larry Gibson]

I have to disagree with 44man on adding tin to WWs. It does change the charactoristics of the ternary alloy and does harden them. My current batch of "new" WWs runs 12 - 14 BHN on bullets after 2 weeks on bullets. the same bullet cast of that same batch of WWs + 2% tin will have a BHN of 16 - 18 after the same 2 weeks. The WW + 2% tin will also WQ harder.

It should be noted that WW alloy BHNs will vary from bucket to bucket because the WWs will be new, recycled and not of the same make. However, how Lyman came up with a BHN of 9 years ago is unknown to me. Perhaps back when Lyman was "Ideal" the WWs for Model T's were much softer??????

Larry Gibson

[fredj338]

Another no. Read the Lyman again, the lowest BHN I have ever gotten w/ straight clip ww is about 11. A 30-1 is not quite 9, closer to 8. A 25-1 is a about 9. The diff is tin & lead is more maleable than any alloy w/ antimony in it. So for solids, not a huge diff, bit for HP, it does matter.

[Whiterabbit]

No.

In real world terms, the 30:1 will be much more ductile than WW alloy.

Fantastic.

The takeaway: Hardness is not the only mechanical property of materials out there.

hardness is not stiffness.
hardness is not toughness.
hardness is not yield strength.

This is all just metallurgy-speak, the way to apply it to bullets I leave to more experienced folks.

[Bret4207]

Fantastic.

The takeaway: Hardness is not the only metallic material property out there.

hardness is not stiffness.
hardness is not toughness.
hardness is not yield strength.

This is all just metallurgy-speak, the way to apply it to bullets I leave to more experienced folks.

I do believe some more folks are starting to see the light!

[Whiterabbit]

http://www.amazon.com/Properties-Materials-Mary-Anne-White/dp/0195113314

Every university engineering student has the option to take even basic (100 level) materials science coursework. Anyone can find an Open University class and pick it up for a reasonable cost per unit. Can't put a price on education. :)

[rr2241tx]

Thank you for saving me from myself. I am indeed planning on shooting the NRA BPCR Silhouettes, so hard boolits are definitely not what I'm looking for. I may try some of the WW in a PJ bore rider on ASSRA targets because I'll be launching those with 4198 and don't need nose slump to help me miss.

It figures, you get told to read Lyman and then find out their data table is pure bunk. Seems like it would be rather a basic priority to get their data tables corrected before publishing yet another edition with fantasy data, doesn't it? Is there an English translation for the instructions on reading the ternary phase graph in Lyman? And would it break their knees to put Farenheit on the diagram? Anybody make a lead thermometer that reads in Centigrade AND is sold in the USA?

[Bret4207]

I wouldn't call Lymans data "bunk", but we;seen the materials change over time too. The basic info is required reading and the foundation for moving on int he hobby. Bhn is a tool, no more, no less, and pacing too much emphasis on it is a waste of time anyway.

You want the secret? Find out what YOUR gun wants with a given load- that's the secret.

[btroj]

Bret is dead on- the gun will tell you what it wants for a given load.

I very rarely look at BHN as it doesn't really tell me much. I prefer to test my bullets I plan to use for hunting and see how they look after impacting the berm. Not very scientific butit works for me.

[44man]

I have to disagree with 44man on adding tin to WWs. It does change the charactoristics of the ternary alloy and does harden them. My current batch of "new" WWs runs 12 - 14 BHN on bullets after 2 weeks on bullets. the same bullet cast of that same batch of WWs + 2% tin will have a BHN of 16 - 18 after the same 2 weeks. The WW + 2% tin will also WQ harder.

It should be noted that WW alloy BHNs will vary from bucket to bucket because the WWs will be new, recycled and not of the same make. However, how Lyman came up with a BHN of 9 years ago is unknown to me. Perhaps back when Lyman was "Ideal" the WWs for Model T's were much softer??????

Larry Gibson
That may be open to question since tin has such a small affect by itself.
Could it be your WW's were depleted of tin and the addition allowed the alloy to form as it should? In other words, tin made the antimony alloy with the lead with a better structure.

[Larry Gibson]

That may be open to question since tin has such a small affect by itself.
Could it be your WW's were depleted of tin and the addition allowed the alloy to form as it should? In other words, tin made the antimony alloy with the lead with a better structure.

WWs have a very low % of tin (.05 or less) to begin with and in a ternary alloy with 2% tin added it allows the "tin made the antimony alloy with the lead with a better structure". That is how it works, which is why adding the tin is benificial plus many times adding the tin also allows better fill out of the bullets in the mould. The tin by itself does little as you mention, but in the ternary alloy it does a lot in conjunction with the antimony. That's why I disagree with your statement of "Adding tin is usually a waste with WW's too". The addition of tin is not a waste as the benifits are real and measureable. I will admit that some lots of WWs do have enough tin to make perfectly good cast bullets. However, many batches/lots do not and ergo the addition of the tin is quite benificial. Probably no real disagreement here just a different look at what's needed is all.

I might add again that my batches of AC'd WWs run 12-16 BHN. The addition of 2% tin bumps that up to 16-18 BHN with less of an extreme spread in the BHN measurement. That is because the addition of tin is making the alloy structure harder and more uniform as you suggest.

Larry Gibson