Water Quenching Observation

[warf73]

Was pouring some Lyman 358456C and some 462420-GC last month, and was taking notes on the entire process.

Was using Lee 20lb pot all ingots were straight WW brn of 13~15. Ran the pot between 700~725* for the entire process. All bullets were dropped into 5gal buck half full of cold tap water.
First brn test was 1 week after casting I tested 10 bullets out of each mold. The average brn in the 357 was 11 the average for the 458 was 16. Saturday I tested 10 from each mold again (this is week 5 since casting) average for the 357 was 14 and for the 458 was 22. All brn testing was done a cabin tree tester.

The first time I did this I was using what ever alloy was in the pot (didn’t know exact brn) and came up with the same exact results and found it odd that the larger heaver bullets got harder than the smaller lighter bullets. As stated both times I was using the same alloy, casting temp, and same water bucket.

Has anyone else noticed this before?

Warf

[rbuck351]

I have found the same although my testing is anything but scientific. Idon't have a hardness tester, but using the thumb nail test my 310gr 45s can barely be marked and the .224s scratch fairly easily. Both being water dropped. I don't have any clue as to why. Can anybody venture a theory? rbuck

[jonk]

My guess would be that the smaller mold and smaller bullet air cools more in the mold and on its way to the bucket thus negating some of the quenching effect. It could be possible that the center of a very large bullet would still be molten or near molten on a hot production set up when it hits the water.

[bobk]

Wish I could afford a hardness tester. I'd try identical boolits into two buckets, one with ice water, the other with fairly warm water. Or, has anyone noticed a variability in hardness, on the day they were quenched, perhaps related to the water becoming warmer as the session progressed?
Bob K

[1Shirt]

It has been my experiance that the hotter the harder with small cals, and I do believe that there is a hardness factor to the positive with the colder water. Also think that the time of drop from mold to water after the sprew cut is a big factor.
The mold that doesn't just drop on opening, and has to be wacked a time or two(or three) is in my opinion a factor of cooling time that probably plays into consistancy of water dropped hardness. That may however just be in my mind as I have nothing specific to varify same. I also believe that 224's and 6MM's should be as hard as possible, and that lino hardness at min is what I want for them. My cabin tree tester says that my 224's and 6MM water dropped run in the 28 bh area tested within hours of casting. I am not concerned with hardness of much over 16 for large dia (.429/457) as I am not really interested in shooting these at much over 1600 fps or so. If I want a soft hunting nose, am hooked on Paco's softening the nose in water method for the larger cals. Have not tried it on the little fellows, and it would probably be a pain to do anyway.
Just my 2 cents!
1Shirt!:coffee:

[Boomer Mikey]

I ran into this while casting 22's as well... my alloy was 50/50 WW/Lino and water quenched bullets were the same hardness as air dropped bullets checked a week later. Paco Kelley says you gotta cast them as hot as you can and he uses a high antimony alloy of magnum shot with tin added.

From Paco Kelley's article "22 Hornet:" "I turn the pot’s temperature up to it’s highest and put a heavy cover of tinfoil over it to keep the temperature consistent, and the oxidation down to a minimum. I flux and stir often while casting to re-mix any oxidation of ingredients. I have never had tin burn off from a hot pot, (I don’t know who started that fable, but it’s nonsense)... the first bullets are as hard as the last... always."

http://www.leverguns.com/articles/paco/22hornet.htm

Same pot of alloy, cast 30 cal 200 grain and 45 cal 260 grain quenched in the same bucket one week later the 30's were BHN 21 and the 45's were BHN 30.

I'll go along with the heavier (thicker) bullets having more hot metal inside until a better explanation comes along.

Paco Kelley says you know the metal is tempering when you hear the bullets sizzle entering the watter... true enough.

Boomer :Fire:

[BABore]

Oven heat treat several from each batch at 435-450 F, for an hour, and quench. Test them in a couple weeks to see what the true potential of the alloy is. Extreme temperature control is needed to get good consistency with water dropping. Your WW's must be of the 2% antimony variety as 22 bhn would be typical.

[DLCTEX]

+1 on the oven method. It's the only way to get consistent results, and yes the heavier boolit holds the heat better and is hotter when it hits the water. With the 22 boolits you have to be fast from oven to water or they will cool some. How much the hardness variation matters is subject to individual needs. DALE

[jhalcott]

The idea that the fatter bullet holds heat longer makes sense. When I cast those 225415's I can pick one up and check it with in a couple minutes. Those big 45-70 slugs stay warm for a lot longer time.

[cbrick]

Boomer Mikey,

Fable? Nonsense? Very little of the hardness of your bullets comes from tin so if you are judging tin loss through oxidation by tested bullet hardness you'll not learn much. I can tell you who started the nonsensical fable though . . . The metals industry.

Tin and the other metals in a lead alloy does oxidize and the hotter the alloy and the more contact with oxygen the faster the oxidation, tin starting at about 750 degrees. The hotter the pot plus the more air contact over the alloy including the stream from bottom pour pots the faster the oxidation. Tins benefit in the alloy is reducing the oxidation of the other metals (the reason for better mould fillout) and your statement of covering the pot and fluxing often is probably greatly reducing your oxidation. Much over 750 degrees though you are reducing the benefits of tin and still possibly loosing some, how much depending on your pot temp.

Also, a bullet sizzling in water does not mean it is tempering (hardening). Drop a pure lead bullet from the mould and it will sizzle also but without antimony in the alloy there will be no tempering.

Rick

[Boerrancher]

I would personally like to see how large and small air cooled boolits harden over time. I would almost bet that the larger ones will still get harder than the smaller ones over time. I could be mistaken, but it would be interesting to find out.

Best Wishes from the Boer Ranch,

Joe

[cbrick]

You could well be right Joe, Veral Smith in his directions for his LBT BHN tester says you will get different results testing bullets and ingots. His reasoning is that the much smaller bullet cools far faster than the much larger ingot. Since rapid cooling is the key to HT'ing lead/antimony alloys I have always followed his advice and not tested ingots.

On a smaller scale a small bullet would cool faster than a much larger bullet. I haven't tested this but it does sound logical.

Rick

[Boomer Mikey]

Boomer Mikey,

Fable? Nonsense? Very little of the hardness of your bullets comes from tin so if you are judging tin loss through oxidation by tested bullet hardness you'll not learn much. I can tell you who started the nonsensical fable though . . . The metals industry.

Tin and the other metals in a lead alloy does oxidize and the hotter the alloy and the more contact with oxygen the faster the oxidation, tin starting at about 750 degrees. The hotter the pot plus the more air contact over the alloy including the stream from bottom pour pots the faster the oxidation. Tins benefit in the alloy is reducing the oxidation of the other metals (the reason for better mould fillout) and your statement of covering the pot and fluxing often is probably greatly reducing your oxidation. Much over 750 degrees though you are reducing the benefits of tin and still possibly loosing some, how much depending on your pot temp.

Also, a bullet sizzling in water does not mean it is tempering (hardening). Drop a pure lead bullet from the mould and it will sizzle also but without antimony in the alloy there will be no tempering.

Rick


Hi Rick,

The statement was a quote from Paco Kelly's article, not my words... For 9 years Paco was the Technical Editor for the bi-monthly magazine of the Cast Bullet Association. His process of using 19 pounds of 6% antimony magnum shot with 1 pound of plumbers tin wipe for fill-out and high heat with "sizzle" into the water was his formula for hard bullets and Paco's advice has never led me astray, his 6% antimony bullets falling from the mold at 800 or 900 degrees sizzling into the water no doubt works fine. [Although Paco doesn't mention it, arsenic in lead shot alloy has as much effect on water quench hardening properties or more than antimony content.]

I've used the oven heat, ice water quench process in the past with good results but I've moved over to the water bucket quench from the mold process for its inherent simplicity and surprising consistency. A comparison between the two processes on bullets used at 500 meters would be very interesting.

If I add magnum or chilled shot to my alloy to raise its arsenic content I believe my WQ 22's would harden. I know that the tin content in my 50/50 is excessive and making my bullets softer. Next time around I'll do things differently.

One of the most interesting things about this forum is the variety of solutions and opinions presented by our resident experts; blindly accepting a single point of view is closing your mind to knowledge.

Boomer :Fire:

[cbrick]

Hi Rick,

One of the most interesting things about this forum is the variety of solutions and opinions presented by our resident experts; blindly accepting a single point of view is closing your mind to knowledge. Boomer :Fire:

Absolutely no doubt about that. In fact, that's why I'm here, :drinks: I've picked up tons of tips, tricks and ideas right here on cast boolits.

Rick

[Boomer Mikey]

Rick,

Thanks for all your outstanding work on lasc.us

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

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

Boomer :Fire:

[redbear705]

Well now....couldn't it just be that the smaller diameter of the .224 at the anvil press point be smaller and the anvil goes in farther because of that? i.e. bigger bullet = more surface area that the anvil has to penetrate?and shows more brinnell?

By the way I was taught that when testing for hardness the test medium was supposed to be a small bar or ingot that had a flat top(testing area) or a test would give innaccurate readings, so if you are testing round surfaces the top paragraph makes sense.



:)

JR