The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > Handloading, Reloading, and Bullet Casting > Bullet Casting

Reply
 
Thread Tools Search this Thread
Old December 24, 2013, 07:02 PM   #1
Old 454
Senior Member
 
Join Date: August 15, 2011
Location: Chesterton Ind.
Posts: 822
16:1 lead to tin

does any one here alloy in a 16 to 1 lead tin ?

How hard in BHN will this bee and what calibers will this be good for.

I ask this as I am trying to reduce my costs of alloy. Superhard and tin are getting a bit expensive, and if memory serves me correctly I read that Elmer Kieth used this ratio, and he used it a 44 mag.

thank you for any advise you all can give.
Old 454 is offline  
Old December 25, 2013, 06:59 AM   #2
Mike / Tx
Senior Member
 
Join Date: April 8, 2000
Posts: 2,101
Should be close to below,

Code:
          Tin     Pure Lead
16 to 1 = 6.25%	   93.8%	   Brinell 11
Should be good for just about any handgun caliber you want to play with as well as a few rifle calibers as long as the fit and lube are correct. Might work better in a rifle being GC'ed though.
__________________
LAter,
Mike / TX
Mike / Tx is offline  
Old December 26, 2013, 06:28 PM   #3
Old 454
Senior Member
 
Join Date: August 15, 2011
Location: Chesterton Ind.
Posts: 822
I have GC 300 grainers for my 454 Casull and for the 357 there just cast, but if I water droped them that might tuffin them up a bit.

but these would be good for 9MM and 35ACP and 380 ACP no ?
Old 454 is offline  
Old December 27, 2013, 04:34 AM   #4
Mike / Tx
Senior Member
 
Join Date: April 8, 2000
Posts: 2,101
If your going to use the 16-1 pure lead to tin only then water dropping isn't going to help you much if any.

Your alloy is going to have some antimony and/or arsenic in it to promote the hardening. The trick then becomes just how hard do you want/need them to be?

To be honest I would certainly give the alloy a try in it's basic state and see where that gets you. Like has been mentioned many times, fit and lube will get you further than hardness in most cases.

With the 9mm you might need to have it a bit harder depending on the powder and initial pressure. That is going to be decided by the bullet, the chamber, and barrel however. If the load isn't overly pressurizing the base of the bullets, and they get a good start into the rifling you might be fine. On the other hand they might get distorted and lead some or all of the barrel.

If you are running them through a lubsizer would start off with them sized to around .357'ish. (guessing here as I'm not overly familiar with the spectrum of 9mm bores.) I know that most throw out .355 as a diameter, so something .001-.002" bigger might work out fine as long as it will chamber without hanging up due to the diameter of the case being too big.

Go from there with some slower powder, which should give you less of an initial blast up the back side, and see where that gets you.
__________________
LAter,
Mike / TX
Mike / Tx is offline  
Old December 27, 2013, 09:40 AM   #5
mehavey
Senior Member
 
Join Date: June 17, 2010
Location: Virginia
Posts: 6,869
16:1 gives you about BHN 8.2-ish



These are actual Brinell impression tests done on exact alloys (with the exception of an old ingot of WW
which I had lying around. Note how WW "relaxes" over time.)
As has been noted in the CastBoolits crowd, there's a lot of "supposed" alloy BHN numbers flying around
-- spread at the speed of internet light. But one of the only true measurements is for Lyman #2

postscript: Not on this chart, but tested, is some REALLY hard alloy supplied by Beartooth & LaserCast
which I use in a 45-70 with fast-rise smokeless powder. It can be done by a combo of antimony
and quenching:

BT's 400 LFNPB, BHN: 23.8
LC's 405 LFNPB, BHN: 21.0

...but is not always in your best interest unless used at relatively high pressures as it won't
obdurate in the bore. (Note also that I use 30:1 for black powder 45-90 loads to get sub-moa groups.
When all the dust settles, this is oft times more an "Artful Science" than straight-forward engineering.)


postscript: Lead-Tin-Antimonony alloys not only change hardness w/ quenching, but gradually gain and
lose hardness with time. Conversely, binary Lead-Tin alloys are what they are within moments of
casting and remain so near forever. Surprisingly, Lyman #2 with it's symetrical 5:5:90 alloy does the
same thing. It is what is is when cast, and stays that way.

Most useful....

Last edited by mehavey; December 28, 2013 at 05:15 PM.
mehavey is offline  
Old December 27, 2013, 07:05 PM   #6
Old 454
Senior Member
 
Join Date: August 15, 2011
Location: Chesterton Ind.
Posts: 822
thanks guys, I might add a quarter bar of superhard 1.25lbs to this mix. we will see.

Damn price of alloys is something else.

By the way, I will be using Hy tek coating from bayou bullets, the black stuff.
Old 454 is offline  
Old December 28, 2013, 06:12 PM   #7
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 21,022
Mehavey,

It would be good to have more details of your testing. I've noticed a problem with my Lee tester reading too high. The tables that come with it match the formula and ball size and compression weight, but the indentations are too small, giving BHN's 3 to 5 higher than expected on most bullet alloys. Anyway, it would be interesting to know your setup specifics.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Old December 28, 2013, 10:38 PM   #8
mehavey
Senior Member
 
Join Date: June 17, 2010
Location: Virginia
Posts: 6,869
UncleNick, I found that there were several keys:

First, I run at least two impressions on each sample. If they match I keep them. If not, I run two more and average the closest three.

Second, I run the impression test for the exact 30 seconds as specified (though I believe the impression size is by its very definition a a self-limiting process if that time limit is exceeded)

Third, I keep the pad of my index finger on top of the test die to feel for any deviation from the plunger being exactly flush -- and therefore provide the "design" spring pressure of exactly 60lbs on the ball. Slight movement of the fingertip pad can provide remarkably precise feel.

Fourth,
Third, I run the ram at its mechanical-max advantage -- thereby exaggerating any movement req'd to change the pressure (and therefore the plunger position).

Fifth (and critical), I've found a simple way to (a) mount, adjust, and stabilize the microscope so I can get exact hands-off readings; (b) set the sample on its own platform that allows me to easily align the sample to the microscope's grid (instead of vice versa); and (b) set up a strong light grazing from ~30° that clearly defines the edges of the indentation. It sets up/tears down quickly, ....and works remarkably well.



Sixth (and lucky) when first testing on RotoMetal's #2 alloy I found the setup provided a repeatable 14.9 BHN on two separate alloy shipments about 6 months apart -- giving me faith in both the the Tester process and RotoMetals. Since Lyman#2 is one of very few true standards ever actually tested (See both LASC and Cast Boolits references), I've baselined from that ever since.

Seventh (and last), when I actually ran the calculations (instead of just blindly following the the little chart they give you), I discovered the Brinell method/number was nothing more than literally the pounds/sq-inch it took to deform the metal. And as the indentation grew the "sq-inches" area was simple spherical geometry of the indent as its surface area grew enough to stop the ball from sinking any further.

The magic was gone...




postscript: The only way I could see this not working was if I pressed the ball onto a digital scale to where it read 60#, and the the plunger didn't wind up flush. Then I'd have a weak spring and the test results would be off.

But if that happened, I just determine what force did produce a flush plunger, plug that number back into the Brinell formula, and get corrected numbers to compare with the ball impression.

Last edited by mehavey; December 29, 2013 at 11:49 AM.
mehavey is offline  
Old December 30, 2013, 05:56 PM   #9
Old 454
Senior Member
 
Join Date: August 15, 2011
Location: Chesterton Ind.
Posts: 822
wow just wow, that some kinda process !

I have the Lee hardness tester and I found it very hard to get a good read on it.

Sounds to me like you have a good way of positioning the scope, if you could please show a pic of how you do it. I get a damn headache from trying to get that scope to steady and get a good read.
Old 454 is offline  
Old December 30, 2013, 06:21 PM   #10
mehavey
Senior Member
 
Join Date: June 17, 2010
Location: Virginia
Posts: 6,869
Actually, it's a whole lot simpler to just do, than to write it up.
(But then I had to go and think about it)

Quote:
"...positioning the scope, if you could please show a pic..."
Did the picture not show up in post #8 above?
mehavey is offline  
Old December 31, 2013, 03:43 PM   #11
Swampman1
Senior Member
 
Join Date: February 17, 2013
Location: South Louisiana
Posts: 432
I'm assuming the microscope has to actually touch the bullet for a true reading?
Swampman1 is offline  
Old December 31, 2013, 06:23 PM   #12
mehavey
Senior Member
 
Join Date: June 17, 2010
Location: Virginia
Posts: 6,869
The microscope does not touch the bullet. It is merely placed
at the focal point (as shown in the photo) to where the bullet
surface/grain is in sharp focus.

.

Last edited by mehavey; January 1, 2014 at 12:09 AM.
mehavey is offline  
Old January 1, 2014, 11:07 AM   #13
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 21,022
Quote:
Originally Posted by mehavey
The magic was gone...
Yeah. When I first ran the formula to verify Lee's tables, because of my odd results, I did it in Mathcad, which automatically maintains units. The result came up in Pascals. Sort of spoiled the mystery.

I didn't realize you were using the Lee unit too. I like the microscope technique, and I'll give that or something similar a try. I'm thinking along the lines of laying the scope and bullet in a short trough of angle stock, rotating to get indentation alignment. But I've taken enough readings to think that's not my issue with the instrument, as the high numbers I get are consistent. I set the thing aside awhile back (the creation date on the Mathcad file is three years ago, and since I created it to try to solve the result disagreement that was probably the last time I was messing with it), but I think I'll get it out again and fiddle.

I've got a good press mountable flat pressure transducer, so I'll give that a try to confirm the force of the spring. I used a bathroom scale three years ago, but the jitter in the needle was high enough to limit my result to 'approximately' 60 lb. I should check the microscope scale against some wire gauges, too, though you'd think it would take some effort to mess that up. Can't hurt to check, though.

I think the 30 second hold is partly to average out jitters and to let the harder alloys relax their springiness a little. With pure lead, I doubt you'd see it make any difference. That's something I should try. I have some pure lead. Also some pure tin. If I get really ambitious I'll try to replicated the 16:1 alloy experiment.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle

Last edited by Unclenick; January 8, 2014 at 08:36 AM. Reason: typo fix
Unclenick is offline  
Old January 1, 2014, 01:42 PM   #14
Old 454
Senior Member
 
Join Date: August 15, 2011
Location: Chesterton Ind.
Posts: 822
Ahhh now I see the pictures.

Question though, in the instructions for Lee's lead tester it says to test the lead that was touching the mold.

I see or what looks to be a double ended wad cutter, the send that you tested is that the end that was in the bottom of the mold ?

By the way that's just ingenious way to do it. I will be making the same set up. Good stuff thank you
Old 454 is offline  
Old January 1, 2014, 05:51 PM   #15
mehavey
Senior Member
 
Join Date: June 17, 2010
Location: Virginia
Posts: 6,869
I just cut that particular bullet nose with a bandsaw to get a flat test surface.
(I've not found cutting it produces significant effects one way or other.)
Otherwise I just test the wide flat nose of a 45cal Kieth for an alloy lot.
mehavey is offline  
Old January 3, 2014, 10:07 AM   #16
salvadore
Junior member
 
Join Date: January 1, 2007
Location: Idaho
Posts: 2,282
The LASC shows clip-ons @ between 11 and 12 BHN, and I asways thought stick-ons went around 6 or less. Do WWs soften after aging? Just checking the chart above.
salvadore is offline  
Old January 3, 2014, 09:06 PM   #17
mehavey
Senior Member
 
Join Date: June 17, 2010
Location: Virginia
Posts: 6,869
The (chart) sample was from clip-on's cast into an ingot ~10 years ago, then measured nine years later.

WW do age soften (after hardening) over time, and can also be annealed to be significantly softer. My BHN=8.8 number above mostly has to do w/ the slow cooling of a massive ingot -- effectively self-annealing the contained alloy.

See HERE

(Note the Lyman reference of BHN~9 is right on.)

Last edited by mehavey; January 3, 2014 at 10:58 PM.
mehavey is offline  
Old January 5, 2014, 01:38 AM   #18
Old 454
Senior Member
 
Join Date: August 15, 2011
Location: Chesterton Ind.
Posts: 822
This is all really good stuff you guys are putting out.
Old 454 is offline  
Old January 5, 2014, 09:12 AM   #19
salvadore
Junior member
 
Join Date: January 1, 2007
Location: Idaho
Posts: 2,282
Mehavey, I have always sized my bullets prior to heat treating them mainly to avoid trying to push a harder bullet thru the sizer, also I didn't know how running thru a sizer would affect the heat treating. Should I do the same with oven annealed bullets to not cause rehardening (is that a word?) by working them thru the die afterwards?
salvadore is offline  
Old January 5, 2014, 09:30 AM   #20
mehavey
Senior Member
 
Join Date: June 17, 2010
Location: Virginia
Posts: 6,869
I admit to not having heat-treated after sizing, but I can't imagine it affecting
later treatment since quenching has its greatest impact near the bullet's
surface (which cools from immediate contact with the water). Sizing just
presents a fresh surface.

As to any work-hardening effect from sizing, that would also seem to be minimal
due to both the relative slowness of the operation, and the lube which reduces
"trauma" even further.

The above is mere Gedanken thought, of course. I haven't actual run for real data (yet).

Last edited by mehavey; January 5, 2014 at 09:42 AM.
mehavey is offline  
Old January 8, 2014, 09:28 AM   #21
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 21,022
Just to make trouble and maybe tempt board member Mete or another metallurgist to contribute, I've always heard that sizing corrupts the surface crystal stricture enough to encourage more rapid migration of alloy constituents to a softer arrangement (age softening). Thirty years ago this was commonly given as a reason bullets shot as-cast (where molded and dropped size allowed that), seemed to lead less and be more accurate than sized bullets. The idea is that the induced softening takes longer than barrel time to occur, so it's OK for the bore to size the bullet during firing, and only pre-sizing would cause the problem. Kind of the opposite of work hardening.

The problem with the above is that I don't think I've seen a metallurgist or systematic testing back it up, so it's just more speculation. And there are, of course, other possible explanations. The main one would be that many revolvers shoot better with bullets sized to fit their chamber throats as closely as possible, and lever guns often seem likewise to produce best accuracy with hard cast bullets sized more like 0.002" over groove diameter than the usual 0.001" over groove diameter. And that's closer to what most molds drop. Being oversize will also raise start pressure and engraving pressure a little, which can improve pressure consistency and lower velocity SD. In the 1911 I've always found headspacing on the bullet in the throat leade produced best accuracy and least leading. Getting a cast bullet aligned straight in a bore seems to be more critical to best performance than with jacketed bullets.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 12:23 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2021 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Page generated in 0.07402 seconds with 10 queries