Quenching, aging & hardness

[ANeat]

You haven't melted the mega-ingot yet? Admit it, you keep it on the coffee table as conversation piece.

Yea im keepin the big ingots for now, mabey not on the coffee table though......

454PB; I did a half arsed test like you are starting a few weeks ago. Straight WW with 2%tin added. The day they were cast air cooled were 10.1 and quenched were 14.3 (12-22-06)

I checked them 3 weeks later and the air cooled were 13.4 and quenched were 20

Checked again today and no change

Adam

[Ranch Dog]

The cast bullet notes page mentioned by 454PB is my web site (lasc.us).

That is an outstanding web site Rick. I sure appreciate all the work you have put into the page and look forward to your next work. Great thread guys!

[454PB]

454PB; I did a half arsed test like you are starting a few weeks ago. Straight WW with 2%tin added. The day they were cast air cooled were 10.1 and quenched were 14.3 (12-22-06)

I checked them 3 weeks later and the air cooled were 13.4 and quenched were 20

Checked again today and no change

Adam

That's good information, Adam, but we know WW's have some arsenic in them. What I'm trying to learn is if pure lead and antimony will heat treat minus any arsenic.

[randyrat]

I just ordered a Cabin Tree tester. I'll be able to find out the tangible difference (with my alloy) in a couple of days.

I have been dropping a few lately, mainly .501-440's. First batch was air cooled and fairly soft. Tonight I dropped another 100 or so and ice-water quenched them. So far, one reject (maybe more to come upon closer inspection).

I did a vise check on the bullets from my first (AC) batch (about two weeks old) and the one from tonight (quenched). The difference is pretty amazing. I know the quenched bullets will harden over the next few days or weeks, but even with the ones dropped just tonight, the hardness of the quenched is (est) 25-30% greater.

I'll know Monday about noon or so if one or the other leads my barrel. I'm off tomorrow so I am going to drop 3-400 175TC's like the ones Yammer casts. I hope to have as good a result as he does.

'Slick

bigslick how ya doing. Yes i check this forum out also. Need any 10mm emties. I'll have more later in the spring.

[randyrat]

That's good information, Adam, but we know WW's have some arsenic in them. What I'm trying to learn is if pure lead and antimony will heat treat minus any arsenic.

From what i have read you need a little arsenic to heat treat.

[Ricochet]

What I'm trying to learn is if pure lead and antimony will heat treat minus any arsenic.

Yes it will. Go back and read that article from Key to Metals.

[cbrick]

Again Ricochet is correct.

454PB, also re-read post 16 in this thead where the Key To Metals article and the Handloader article was discussed.

Rick

[BigSlick]

Hey Randy

Good to see you here. I can always use a few (zillion) 10mm brass.

I've been hanging out over here trying to catch on to some of the details of casting. I'm still ignernt, but minutely less so.

At this point, my ignorance of casting is exceeded only by my disdain for factory ammo. I got the ww, got a few moulds and the desire, maybe this blind hog can find an acorn or two with perserverance.

I sized a few more 440gr honkers today. I enjoy this stuff so much I can't seem to stay away from it.

From my first batch ever... and with my second attempt at home made lube (first batch was a disaster) :



________
Piercing

[Dale53]

BigSlick;
Those are nice looking bullets. I would say that you are on your way!

Dale53

[MTWeatherman]

cbrick:
Congratulations on a very fine web site. I have a loose leaf notebook that I keep notes in on various cast bullet topics for reference. I copied your "Cast Bullet Notes" for reference long ago. Its got more "to the point" information in as concise a package as I've seen.

Thanks for your expert input on the heat treating subject. I'm looking forward to that update in your "Cast Bullet Notes". Please let us know when its ready so we'll be able to peruse it.

I do a significant amount of oven heat treating with straight WW. I've found it necessary for a 9mm, a Microgrooved .44, and more recently a .223. I know that the BHN can be varied by oven temperature but usually go for the hardest bullet possible. However, I've thought that perhaps one could also adjust the heat treated BHN downward by adjusting the amount of lead alloyed with the WW. Based on my understanding here, thats really not the case...a 1% antimony/lead alloy in the presence of arsenic would be just as hard as a 3% WW, just take longer to accomplish it.

Is there absolutely no decrease in the final BHN by alloying WW with lead before heat treating? If so, it would seem one has the possibility of going 2 parts lead to 1 part WW (or at least 50/50) for heat treating to a high BHN. All that would be required would be a little patience before shooting. It would be a great way to use up some of the soft lead I've accumulated over the years.

[Ricochet]

I've been finding that very soft scrap lead of unknown composition, that I can thumbnail dent easily when air cooled, gets quite hard after spending an hour at 475°F in the oven, quenching, and waiting a few days. Don't have a hardness tester, but I've tried cutting the stuff with a knife after 4 days and found it to be about as hard as air cooled wheelweights then. Probably gets harder as more time goes by. With about 1 part wheelweights to 5 parts of this stuff on up to half and half, when quenched and aged I can't tell the difference in hardness with my crude methods from pure quenched wheelweights. I broke my loading bench trying to size 20% wheelweight boolits quenched this way that had hardened overnight. They ring like bells when you shake 'em around together, too. The pure old soft scrap stuff still sounds dull as a lead boolit is expected to, but gets a lot harder than you'd think.

[cbrick]

cbrick: Congratulations on a very fine web site. I have a loose leaf notebook that I keep notes in on various cast bullet topics for reference. I copied your "Cast Bullet Notes" for reference long ago. Its got more "to the point" information in as concise a package as I've seen.

Thanks, words like that make a lot of work well worthwhile.

I know that the BHN can be varied by oven temperature but usually go for the hardest bullet possible.

The hardest bullet possible isn't really needed or desirable for most situations. I started out heat treating years ago with this notion also. I did a lot of long range revolver testing, 150 meters scoped from the bench with a FA 357 9". All of the testing was with virgin brass and as identical of loads as I could make. All used the RCBS 357 180 gr silhouette bullet cast of WW + 3% tin at 190 gr, the only thing I varied was the bullet BHN by heat treating. All shooting was done over an Oehler 33 and the casting, heat treating and shooting lasted for months. The best accuracy, the best chrono numbers were with 17-18 BHN. With each increase in BHN all the way up to 30 the velocity came down, groups opened up a bit but it still shot pretty well. With each decrease in BHN down to 11 groups opened up. The one thing that destroyed groups was mixing bullets of different BHN. With bullet hardness ranging from 16 to 22 in the same five shot group most shots missed the 150 meter target completely.

However, I've thought that perhaps one could also adjust the heat treated BHN downward by adjusting the amount of lead alloyed with the WW. Based on my understanding here, thats really not the case...a 1% antimony/lead alloy in the presence of arsenic would be just as hard as a 3% WW, just take longer to accomplish it.

Is there absolutely no decrease in the final BHN by alloying WW with lead before heat treating? If so, it would seem one has the possibility of going 2 parts lead to 1 part WW (or at least 50/50) for heat treating to a high BHN. All that would be required would be a little patience before shooting. It would be a great way to use up some of the soft lead I've accumulated over the years.

This could make for some pretty interesting testing, are you volunteering? If you would like to experiment with this, I for one would be all ears. All of my heat treating has been with wheel weights and the variation I was refering to in the earlier post was the variations in the composition of wheel weights. I have never attempted blending lead with WW and heat treating but the idea is intriguing just to learn the results and add to the knowledge base. The education continues.

Rick

[Bass Ackward]

I have HT all mannner of lead, but never tried "pure" lead because I couldn't see the point.


Lead can only HT to a maximum practical hardness of 35 BHN. Once you go so far down in antimony content, your top end hardness potential drops. In addition, your temperature flexibility, to vary and control hardness becomes narrower. And the lower the antimony content, the lower the final hardness will be after the softening degradation occurs. I have 15 year old WDWW that is still 20 BHN. But my first attempts at 50/50 are down to 11 BHN now.

You can give any mix a kicker by adding magnum grade shot to increase the arsenic content, but you are also adding antimony that you purposely diluted down, so it is kind of self defeating unless you wanted to see what lino can REALLY do. Then the arsenic is worth it.

Increased arsenic content "may" delay or slow the softening process too as I have noticed this in a couple of cases, but I never specifically tested for it.

[cohutt]

cbrick, dittos. I found and bookmarked the lasc site when i decided i wanted to begin thinking about casting. Aneat's new testing project is using pure lead from this first batch; cbrick if you are interested I will be happy to send you some to use in your own tests as a "thank you" for the lasc, the lead being of a know origin and composition for control purposes..

Bass-Ackwards, I'm using pure lead as a starting point since i have a friend/client in the shielding business who graciously lets me have scrap when i ask. It is very clean and also each batch they order is send down to Georgia Tech and tested via spectrograph or something along those lines, so it is of known makeup- 99.99... etc. Adding lino to it seemed easy enough to get the antimony & tin...
[ I approached from this perspective since lead is always the 90%+ component of every bullet casting alloy formula I've seen Of course i didn't realize at the time that I wouldn't easily find a similar source for tons of free clean arsenic, tin and antimony of certifiable composition. ]

To everyone else in this thread, thank you and please keep posting- I figured this was long ago settled and that this would be a 3 post thread including my thank you. The more i know the more i realize what i don't know.

[MTWeatherman]

cbric:
I checked the date on my printed copy of your notes...08/01/05. I used it as a bookmarked favorite well before that so you’ve had that web page for some time. I have absolutely no doubt that a hardness less than maximum may well be the most accurate...the obturation issue would likely make that especially true in revolvers. I just haven’t done much experimenting with it. When I decide I need a hard bullet, I just go for it. In all cases I’ve found it necessary, it solved the leading or accuracy issues and I went no further.

At this stage, I’d not be the best choice to do a test as I don’t have a hardness tester. I use a “relative hardness” test when heat treating. I have linotype bullets precast for each bullet I heat treat. If I have any doubts about the success, I simply place the heat treated and the linotype bullets nose to nose (all have meplats) in a vise, and compress them against each other. If the heat treated bullet wins the deformation contest, I consider the heat treating a success. I have determined hardness fairly reliably by compressing a 3/8 ball bearing between a cast of pure lead and one of the tested alloy in a vise...then using the method described in Lyman #3 to determine the actual BHN. Seems to work well enough but set up is a pain...not something I’d want to do very often.

I’d be surprised if someone hasn’t already done the testing, especially given the development interest of the board members here. It sounds like Bass may already have been there.

Bass:
Were you able to determine the initial BHN of that heat treated 50/50 mix? Any further information you could provide on your experience would be appreciated.

In the relatively near future, heat treating may become more of a necessity for dedicated casters. I believe that the days of freely available WW will disappear as manufacturers are forced to convert to steel and zinc due to environmental concerns. WW will become in short supply and with it our main source of bullet alloy. What better way to extend our supply of bullet alloy that to heat treat WW/lead alloy bullets...even if we don’t need hard bullets?. To use a purely hypothetical example, if the BHN of ACWW meets your needs and a 4 to 1 lead to WW alloy could be heat treated to equal it...you could turn 1 pound of WW into 5 pounds of useable alloy...perhaps as simply as water quenching. We could live with less WW or at least hoard fewer of them. That is, of course, assuming that lead, which is considered a toxic substance, will still be available to the public without a hazardous materials license.

Here’s another reason for interest in the subject...convenience. Suppose, for example, that a correct WW/lead alloy could be found to produce a heat treated BHN of about 15 with water quenching. That alloy then would function similar to Lyman #2 in use...a BHN between ACWW and HTWW with no finely tuned oven treating required...just quench.

...and that doesn’t even address finally finding a use other than barrel slugging for those stick on WW.

Really curious if anyone has any results on the heat treating of WW/lead alloys they could share with us. If not, I would definitely consider getting that hardness tester and doing some experiments myself.

[Ricochet]

I have HT all mannner of lead, but never tried "pure" lead because I couldn't see the point.

The point I've drawn from my experience is that "pure" lead by the thumbnail test may not be that pure. A little alloy can make it quite a bit harder after quenching and aging.

So far as water dropping goes, it's just easier to cast that way, whether or not you want boolits hardened. I've water dropped them and later annealed them in the oven.

As for temperature ranges, with lower antimony levels you should have a WIDER temperature range that'll give maximum hardness. The antimony will start to go into solid solution at some minimum temperature regardless of the total amount present. A lower amount will get it all into "solution" at a lower temperature, as the saturation is lower. But it can be heated to a higher temperature before reaching slumping and melting points. Now, it may well be harder to try to achieve some intermediate hardness through the heat treatment process. I haven't been trying to do that, just to put whatever's in there in a solid solution, quench it, and let it age by itself. I do expect that if it's accurately measured the hardened metal with lower alloy content will be softer, but it gets pretty hard.

[BruceB]

This is a fascinating thread, and I read this type of discussion with the same sorta "spectator" view as I would watch a tennis match or a slow-motion semi wreck on an overpass.

The more I know about the fine points of alloying and the minutiae of temperatures, quenching, catalysts and all that, the better-informed I feel.

I'm very grateful to you who find the time and energy to do the research and PARTICULARLY, to report it here where many can benefit from your work.

BUT (and I say this mostly for any new casters who may find themselves in this seminar).... I read it avidly, but I don't need it for MY purposes.

We all find our niches and methods in this great hobby, and after exactly forty years of casting this month, I find that KISS is where I'm at. This is most emphatically NOT criticism against those of us who enjoy the scientific approach!

SO, I water-drop most of my rifle boolits, all of which are made from plain wheelweight alloy of whatever weights came to hand for smelting. No tin, no other additives. Most handgun boolits are aircooled WW. The longer I shoot, the less need I see for hard bullets even in my rifles, so I don't worry much about age-softening over time. Don't even have a hardness tester.

I do cast a lot of bullets, and I do a lot of shooting. I enjoy the dickens out of the whole procedure, and reading threads like this one is an integral part of the enjoyment. I just don't want any newcomers over-awed by the science and dedication presented here.

You guys are great.

[cbrick]

BruceB, you are absolutely correct. I am currently writing an article on heat treating and one of the points I am trying to make is getting them too hard for the application. It's not needed and can quickly become detrimental. Most handguns do indeed shoot air cooled WW very satisfactorily. My 308 rifle shoots air cooled WW at 1900 fps with zero leading.

Here is a sneek peak at the article, its not completed yet, especially the chart but this is what I have so far.

http://www.lasc.us/HeatTreat.htm

Rick

[Bass Ackward]

Bass:
Were you able to determine the initial BHN of that heat treated 50/50 mix? Any further information you could provide on your experience would be appreciated.

MTW,

My initial hardness was 6/7 BHN if I remember correctly. (?)

Bob (45 2.1) was / is the driving force behind 50/50 on this board and will probably answer any questions if you PM him. He is the most familiar with it that I know.

And necessity is the mother of invention. Believe it or not, at one time antimony was a dirty word to casters. You can buy the stuff in several forms and alloy it in yourself. It's a PIA if you don't follow the instructions. Here is the instructions from Bill, the Antimony Man.

ANTIMONY
The product looks like small metal gravel. It is quite pure with dust and fines removed.

ALLOYING FLUX
The flux is a pink powder which absorbs moisture so it must be stored in a sealed container with a desiccant such as silica gel when not in use. It has a MAXIMUM alloying temperature limit of 635F. The lowest temperature is that where the metal to be alloyed, LEAD, or LEAD/TIN or TIN is completely liquid. These temperatures range from 621F for pure lead to 450F for pure tin. 93/7 tin/antimony pewter is made at 500F.

PROCEDURE
1. Start with a clean pot and clean metal or alloy. Bring up to operating temperature, minimums as given above.
2. Spread a very light film of flux over the melt surface and let it melt. The simplest applicator is a 'salt shaker' type container. Letting it melt insures evaporation of any adsorbed moisture.
3. Sprinkle on a light coat of granulated antimony. Follow with another thin film of flux. When the flux has melted the antimony will have warmed up enough to not 'chill' the melt.
4. Start stirring slowly and smoothly. The antimony and flux float so there is no advantage to agitation. Stirring rolls the antimony particles over in the film of flux on the surface of the melt. EXCESS FLUX is indicated by a dark foam or crust. As the antimony is encased in this flux it will not contact the melt and solution slows and stops.
5. Learn the lesson, skim off all foam, antimony and excess flux. When cool, wash with water, the flux and flux products dissolve leaving the antimony. Dry it.
6.Start over again and control flux properly. As the antimony goes into solution, add very thin film of minimum flux when reaction appears to have stopped and continue stirring.
7. Eight to ten minutes is usually adequate time to make linotype IF the procedure is followed properly. As with any process it takes practice to maintain proper temperature (as low as possible), add minimum flux and spread antimony in the proper amounts.

[454PB]

I didn't even mention that although I've done heat treating and water quenching for over 20 years, I really feel like it's solution for a problem I don't have. I have enough wheelweights, type metal, babbitt, and solder to create about any alloy and hardness desired.

I also have found that the end result is variable, and will change in hardness over time, depending on the methods used.

As I said in my original reply, I didn't think heat treating would work without arsenic, and I sighted the quote from The Handloader from cbrick's web site as an example of "accepted" thinking. I now know that it is untrue, but I'm still curious enough to do follow up testing to see how a linotype/lead mixture will hold up to the aging process. At times I've spun my wheels expending a lot of effort and time on heat treating, only to find that the boolits I spent so much time on 5 years ago are now the same hardness they would have been if they were simply cast with a traditional alloy in the first place. I do a lot more casting than shooting, especially in the winter. It's normal for me to cast 3000 to 6000 boolits in the winter, so there are always old boolits around. As MTWeatherman said, if your supply of alloy is dwindling, all those attempts are worthwhile, but I don't have that problem.

It's obvious that a lot of old theories and practices are untrue. Fortunately those on this forum have been instrumental in disproving a lot of bad information for the benefit of the newer and younger casters. A simple question by a relatively new caster has taught a lot to us old dogs ( at least this one).

Isn't that what it's all about?