Hardness of Linotype - very inconsistent

[Griz44mag]

I have been scrounging and buying material from a lot of different places over the years, and have found that what folks are calling Linotype is probably just about everything that was ever used in the printing business. This year I decided to start getting serious and getting the many boxes, buckets and sacks of stuff melted down into ingots. Material still in the form of type, letters, graphics blocks, etc.....
For the purpose of having a controllable process of mixing alloys for a targeted hardness, I have batched materials from each source that was over the small lot size . I have discovered in the process, that the material called Linotype is VERY inconsistent in hardness. After converting to ingots, I stated testing each batch and recording the hardness. From different batches of materials that look almost identical before smelting, I am seeing material hardness on wheel weights from 8 to 14, and on "Linotype" from 16 to 27. If you are mixing your bullet casting materials using the x number of pounds of wheel weights with y number of pounds of stick on with z number of pounds of Lino, then the end result is just as unpredictable as the material you started with. If you want repeatable results with your casting and the results, then test your lead for hardness and know for sure what you are shooting.

[454PB]

I agree, and I've found the easiest way to handle the problem is to melt down a large batch and cast it into ingots. I did one batch of 200 pounds and it ended up around 27 BHN.

Frankly, it's not worth fretting about unless you are selling it and claiming a certain hardness.

[cajun shooter]

The re are many people, like the ones on E-Bay who have never cracked the cover of any book on metals and bullet making. They are selling it all for Linotype as they see what it brings.
Print shops had different metal for different jobs and even recycled the metals on hand. Several look at Mono-type and think it is just large Linotype. They smelt them down together and sell it all for Linotype.
The only way I will purchase from an unknown seller is to contact him and have a little Q&A time to see if he is informed or just selling what he can get his hands on.
I also use my Cabin Tree tester on all metals that go into my smelting pot as a batch of ingots.
COWW from the NE will show up to 15 while the Southern brand stay around 9-11 BHN. Big difference when trying to alloy a known BHN range.

[btroj]

Hardness is NOT a reliable method of determining alloy composition.

Ingots cool at different rates, this can affect hardness. I wouldn't be at all surprised to find a 2 pound ingot that measured 5 points difference in various points on that ingot.

Was the it the first from that cold mould? Cooled faster. Was it the last and it took a minute of two longer due to a very hot mould? Was it the last from that pot of alloy so the alloy itself was much hotter when poured?

Too many things can affect hardness and none of them tell us squat about what is in the metal itself.

You also may have some worn out Linotype along with some individual blocks that are actually monotype. Vastly different metals.

My take on it is this- make a big batch, use it up, and don't sweat the numbers. It will either work or it won't. The gun isn't going to care one bit.

If variations in hardness bother you then don't measure the hardness!

[cbrick]

Hardness is NOT a reliable method of determining alloy composition.

Ingots cool at different rates, this can affect hardness. I wouldn't be at all surprised to find a 2 pound ingot that measured 5 points difference in various points on that ingot.

Too many things can affect hardness and none of them tell us squat about what is in the metal itself.

Exactly!

And your bullets will cool at a radically different rate than any ingot meaning they will also test different than the ingots they were cast from.

This why water dropping will harden a lead/antimony alloy, it cools far faster. The mass of an ingot cools much, much slower than the much smaller mass of a bullet.

Rick

[btroj]

I may start taking WW/PB 50/50 ingots and water drop them. I could then send them to people as Linotype and tell them to use a hardness tester to show it was linotype.

I may retire early......

[MT Chambers]

Over time water dropped bullets will soften up, linotype shouldn't, that may end your retirement.

[btroj]

By then I will have made my money! All I have todo is make sure people continue to equate BHn with alloy composition.

[cbrick]

Over time water dropped bullets will soften up, linotype shouldn't, that may end your retirement.

Over a rather long time.

A few years back while cleaning out the back of a cabinet I discovered a box of 100 RCBS 35 200, heat treated to 30 BHN. Properly labeled with date, alloy, tested BHN ect. I thought they would have age softened to putty in 10 years but they were still 26 BHN. 26 BHN is still way too hard, guess I'll have to wait another 10 years and see if they soften enough.

Rick

[geargnasher]

I have some monotype in original form that tests 7.5 bhn. There are mainly four different type metals, and Linotype will usually be found in pigs, since the print that the machine generated was recycled every day. Very few people have seen Linotype printing plates as they come out of the machine. The constant remelting and skimming oxides depleted the alloy of tin and antimony rather quickly, and print shops were supposed to add a sweetener of high antimony/tin content to the melting pot occasionally to combat this, but many didn't, and the pigs you may come across can be of any percentage imaginable. The other type metals are supposed to be of different compositions for different purposes, so just because it's a print letter doesn't mean it's even supposed to be 84/12/4.

If you have a bunch of it, melt it all together in a giant batch and have it assayed so you KNOW that you have.

Gear

[Griz44mag]

Proof is in the puddin' - so to speak.
First, let me make sure that nobody has misunderstood my observations and statements about lead hardness. At no time EVER have I stated that alloy composition could be determined by hardness levels. Frankly, I don't give a D about the composition of the materials I cast, only that it has enough tin in it to cast a nice bullet. Adding 1% to an alloy that does not cast well will make it cast very well, and that can be added without making anything but a very minor impact on hardness.

The first batch of this material I smelted was all in type form, still in small letters. 90# of it. It as all melted in one pot at one time, fluxed with alox, sawdust and some leftover candles from Christmas a few years ago. The alloy oatmealed up just after the initial melt, but re-blended after gaining another 100 degrees of temp. I believe this to be the antimony trying to separate out, but don't know for sure since I can't test for antimony in a pot that hot. At 800 degrees, the material in the pot had a slightly lighter than lead color to it, almost silvery in nature. It was all cast into 1# ingots. I have 8 Lyman 4# molds, so it took 3 batches to get it all done. I let it sit for a couple of days, and tested it, random samples of ingots from the first one cast to the last one. I think I tested 10 ingots total. Every single ingot tested to 24.8BH. My target for the material was the Mihec 359-125 mold, with the hollow point pins mounted. So I mixed this material with some range lead which had been tested to 12.5BH. Mix rate was 7 to 3, with the goal for the final hardness to be 21. I did a total weight of 10#. The test on this mixed material showed a BH of 21.8. A little higher than my target, but not far off. My goal was for 500 hollow points. Since the hollow pointed version from this mold weighs in at 115gr, 10# was enough with a little to spare. I sat down and cast this batch on Friday night. The pot was kept at 750 degress, the mold on level 4 on the hotplate. I don't know the mold temp at this level, just that all my molds that start at this level off the hotplate cast nice bullets right off the bat. Ten pounds of alloy through the Lee pot later, the bullets are cast. I really like this MP mold, it's first class all the way.
http://www.texas-chl.com/images/DSC00885.JPG
I used the same firearm for all of the 9mm testing I did, a RIA 1911 5" tactical.
I would really like to use an XSE 5" Stainless Colt in 9mm, but Colt has not seen fit to grant me any wishes lately.
Saturday AM I sized\lubed them to .358 and with home brew lube (40% beeswax from RandyRat, 40% LOX from White Lube Company and 20% CR from White Lube as well.) I loaded them hot, which was the goal, with 6.3gr of Accurate #5. Loading at this same level with 12.5 BH lead 3 weeks ago produced a barrel heavily leaded with only 100 rounds shot through it. Today I shot all 250 rounds I had loaded with the 21.8 BH. Grouping accuracy was excellent at 20 yards, a bit low but this gun always shoots a bit low, with a very decent and snappy recoil. There was more smoke than I remembered from the last round of testing, but that might be attributed to the lack of wind today. When I got home, I removed the powder and wax fouling with a few passes of Eric's red, ran a dry patch and then examined the barrel to see what the leading was like. I had a few very light streaks from the throat to about 1/2" into the rifling, then nothing. It was clean and shiny.
My experiments with the 9mm over the last month have proven to me without any shadow of doubt, that fit (#1) and hardness/pressure (#2) are the two most important factors. And I do agree, they are not the ONLY factors. But to say hardness is unimportant is like still believing in a flat earth. If hardness did not matter, then why don't we shoot pure lead in everything? And since hardness is not the whole story, yes, the other factors do need to be considered. I consider myself lucky to have obtained a large supply of material for a very reasonable price, and as the rest of the material gets smelted down, it too will be tested for hardness and so marked.

As always, YMMV, but the science of it, will always rule.

[btroj]

Water drop the bullets and what happens? Or age them for a month or so?

Hardness can change or be manipulated for an alloy, composition can't. Alloy doesn't change over time, hardness does. Water dropping doesn't change composition, it does change hardness.

Hardness tells me something about A physical property of a substance, alloy composition tells me WHAT it is. That is science.