20:1 needed or just BHN 10 for BPCR

[40-82 hiker]

Yep, 6.45 is not hardly "approximately BHN 10"

I am coming to the conclusion that the most important part of this hardness testing is the documentation we use to check our results with. So, what is considered the "holy grail" of BHN values for boolit hardness values? This would include CORRECT values of the old mixes (e.g., 20:1, 30:1, so on).

[montana_charlie]

I am coming to the conclusion that the most important part of this hardness testing is the documentation we use to check our results with. So, what is considered the "holy grail" of BHN values for boolit hardness values? This would include CORRECT values of the old mixes (e.g., 20:1, 30:1, so on).

Again, it is the lead/tin alloys that can't be trusted in the old charts. Antimonal alloys might be listed accurately because they actually got tested in later years.

But, for the lead/tin alloys, this is what I gleaned from the 'researcher who remains nameless'.
Each of the alloys except the Lyman #2 age-softened to the listed hardness. The softening time varied between 12 hours (20-1) to 4 days (16-1).

The Lyman alloy probably age-hardened because that's what antimonal alloys do. But, how long it took to reach it's advertised 15 BHN is unknown to me, as is it's hardness immediately after being cast.

Certified Lead: 4.5
Certified Tin: 5.0
Certified 30-1: 6.66
Certified 20-1: 7.8
Certified 16-1: 8.2 for a year, then softened to 7.39
Certified Lyman # 2: 15.4

Now, y'all know pretty much everything that I know about this subject.

CM

[ColColt]

I got curious as to the hardness of a pound block of tin I ordered from RotoMetal about six months ago and according to my Lee tester, it read .096 which is BHN 5.2...pretty close.

[montana_charlie]

I got curious as to the hardness of a pound block of tin I ordered from RotoMetal about six months ago and according to my Lee tester, it read .096 which is BHN 5.2...pretty close.

The 'old charts' have tin listed at 7 BHN.

[Dumasron]

Assume there is a bullet design that has no variable other than hardness.
Q1. How much change in bullet hardness is required to change the impact point by 1 minute?
Q2. Does cast bullet weight correlate inversely to tin content?
Q3. How much weight variability adds up to missing a ram?

How does Rockwell "B" scale correlate to BHN?
Thanks

[John Boy]

John Boy, are you water dropping the 3 - 7 alloy to get bhn=15.4?

Huntrick ... No. All the aged air cooled clip ons that I have made into ingot over the past 5 - 10 years have either been Bhn 13.5 or 15.4. I keep reading in the alloy calculation programs the WW's are Bhn 12. Close to 2000 lbs of ingots, have never had an aged batch at Bhn 12

[huntrick64]

John Boy ... Once again this faceless medium called "the internet" has tricked me! When I first read you statement:

"Been mixing the 3 -7 alloy using 3 parts clip on weights with a Bhn 15.4 (close enough to Lyman #2)."

I was thinking that your 3-7 alloy had a BHN of 15.4, not that your wheel weights used in your alloy had a BHN of 15.4. That was why I questioned how you got there, because I have never been able to blend a soft metal with a hard metal and end up with an alloy harder than the hard metal was to begin with. See my confusion? My bad.

Rick

[John Boy]

See my confusion?

Yep and I have them too. Happy that you got it sifted out. It is a good alloy combination IMO

[Boz330]

This may not correlate to anything useful but I borrowed a friends Cabin Tree tester and all of the different batches of WWs that I had, came out at the same as 20-1 on the tester. The second thing I found was that shooting WWs in my BPCR gave very good results for 10 to 15 rounds then went south because of leading. Another one of the guys I shoot with uses nothing but WWs and has no trouble from them. I stopped using WWs and the tester and throw 20lbs of pure with 1lb of tin in the pot and cast. I don't weigh just throw 1lb Lyman ingots in the pot. It varies a little bit on weight but I figure that I can't hold it better than that anyway.

Bob

[cajun shooter]

First thing I would like to interject into this thread is that all of the newbies need to go to the sticky section. Look for the book written by Glen Fryxell and Ron Applegate. It is called From Ingot To Target. It is about 172 pages in length and and it would be of great value for the rest of your life. Glen and Ron combined probably know more about the art of casting and shooting than most forum members. They could of easliy published this book and made a hunk of money but gave it to this forum for free. I printed it out and put it in a 3 ring binder. I started casting and reloading in 1969 and I still have used the book many times.
Now as far as WW's go, John Boy and I have discussed this subject before. I live in South Louisiana and I have never seen a WW in this area that test much above a 10 BHN. I have found a few that go to 12 BHN but they are very rare.
I use a Cabin Tree tester as opposed to the Lee. The Lee has been found to give good results in Lab Testing conditions but I find flaw with this tool and the way a reading is taken. It all depends on how good your eyesight is for one thing. It also depends on you keeping the pointer rod flush with the top of a die for 30 seconds which most will screw up. Then last it gives you a chart to compare your results with the standard test sheet. It has a lot of areas left open for mistakes to be made. The Cabin Tree only requires you to line up two lines after giving the handle a 360 degree turn.
They gave the Lee to 10 persons in one test of it and each alloy tested was given 10 different readings.
For the new member who has yet to purchase a tester, save your funds and purchase the Cabin tree.
As far as alloy goes for shooting BP I'll just say go to the big shoots and see what the winners are using. I don't think you will find Lyman #2 as being very common or for that matter you m,ay not even find one shooter with it.
Besides reading the book by our two great members, you should also read the book by Mike Venturino by the name of Shooting Buffalo Rifles Of The Old West. It has a very respectable section of this nations top shooters giving you the information on what works for them. Take Care Fairshake