Tell me about Brinell Hardness....

[45 long]

I'm loading for 45 Colt. I have 200 gr RNFP hi-tek coated bullets from both MBC & Acme. Noticed that MBC has a BHN 12, while Acme BHN is 16.
These are light loads in the 700-800 fps range. Is one more suited for my loads than the other. From my limited understanding it has to do with the bullet sealing to the bore.
Also just noticed that Midway is carrying MBC bullets now. (or I just didn't notice it before)

 

[Obturation]

From MBC site.

 

[whughett]

Its complicated. The harder the bullet the faster you should be able to push it. At 700 to 800 you’d not have a problem with either I’m thinking. I’m assuming you mean powder coated, a plastic. Powder Coating enthusiasts swear by it. If commercial ask the producer for highest recommend velocities.

 

[black mamba]

MBC sells coated bullets in both 12 BHN, appropriate for lower pressure loads, and 18 BHN for higher pressures and more penetration.

 

[earlthegoat2]

I really am a teenager when it comes to lead bullets but let me hazard a WAG and say that I would suspect softer bullets obturate the bore with less velocity (pressure) and harder bullets require more pressure to obturate the bore.

Its complicated. The harder the bullet the faster you should be able to push it. At 700 to 800 you’d not have a problem with either I’m thinking. I’m assuming you mean powder coated, a plastic. Powder Coating enthusiasts swear by it. If commercial ask the producer for highest recommend velocities.

This plays off the above thought but I think it is more like, the harder the bullet, the more it should be pushed for maximum efficiency and less leading. Otherwise, the harder bullet may not seal to the bore under pressure and the pressure wave/flame may be able to bypass the harder bullet through the grooves and the rifling which is why gas checks also exist.

I believe the OP needs the softer of the two bullets since it would not be too high intensity of a round.

 

[45 long]

I think earl's right, BHN 12 would be ideal for my use. Be interesting to see how the Acme bullets perform. Thanks Obturation for the info. Judging by your user name, this was right up your alley.

 

[twistytorn]

At the pressure levels to generate 700-800 fps out of a .45 Colt, even 12 BHN is more than required. Coated lead bullets are very forgiving, though, so even if the fit isn't great you won't get leading.

 

[Texas10mm]

http://www.lasc.us/Fryxell_Book_Chapter_3_alloySelectionMetallurgy.htm

Bullet hardness is WAY overrated. Elmer Keith did all the development work of the 44 Mag with a BHN 11. Read that twice, let it sink in. That was what was considered "hard cast" of the time.

Now we see commercial bullet casters using alloys of up to BHN 24 with crayon lube and people wonder why they are getting leading.

Bullet fit is MUCH more important than lead hardness.

1. Slug your bore. Measure the slug.
2. Now measure your cylinder throats. The throats should be slightly larger than the bore in an ideal situation.
3. You want bullets that can be pushed through the cylinder throats with light pressure.

 

[forrest r]

Lead bullets bhn is soooooooo over rated!!! Way too much urban legend/internet myth out there coupled with parroting of mis-information.

Bullet mfg's play a huge role in this, they make bullets that are too hard. These hard bullets are good for shipping. they don't get dinged up. Same goes for their rock hard lubes. The cheapest alloy they can find they use to cast bullets with the main metal in the alloy for hardening lead is antimony. Great, now you got a rock hard bullet cast with a bunch on antimony. The 1st thing that happens with most in-experienced reloaders of cast bullets is they shoot 10/20 of them and then look at the bbl and tweak. What they think they're seeing is lead/leading when in reality it's called antimonial wash. The other issue reloaders have with these rock hard bullets is you shoot too light of a load and you will get leading.

What you really want is an alloy that is not only soft but it also should have elasticity. Tin plays a huge role in this, but tin is also $$$ compared to antimony.

Myself, I wouldn't use those 18bhn bullets for those lite 45lc loads, heck the 12bhn bullets are borderline too hard. Been casting my own bullets a long time with 99%+ of my cast bullets being cast with nothing more than range scrap that is 8/9bhn air cooled and +/- 12bhn water dropped.
air cooled ='s cast bullets dropped from mold and left to cool in air.
Water dropped ='s bullets cast from mold dropped in water as the mold opens and cools as soon as they hit the water.

Water dropping cast bullets makes them harder then their air cooled base alloy.

The only time I use a hard alloy is for cast rifle bullets and they are cast with a 14bhn alloy. I've run that 14bhn alloy over 2600fps in a 308w and typical loads up to 42,000/44,000psi. The alloy can handle more pressure but the bullets can not. They can't take the rpm's of the the hotter loads.

These are recovered bullets from when I was testing different alloys for wv 308w loads.


As you can see the lower velocity loads shattered. Too hard of an alloy!!! Alloys That 2300fps bullet pictured is a 230gr bullet out of a 308w with a 50,000+psi load pushing it. This is the alloy I use for all my high velocity/high pressure cast bullets (14bhn)

At the end of the day I'm using a 14bhn alloy to push bullets up to 2600fps+ with load up to 50,000+psi. You're using a 16bhn bullet to go 800fps with a +/- 12,000psi load.

 

[whughett]

I based my response only on my own experience of casting lead bullets from whatever sources, well not whatever for the first 15 years as it was lead from telco, cable sheaths, splice closures and the like. Always in 38,44 and 45 caliber. Now it’s generally what ever I dig out of the clubs back stop. Not a clue as to hardness, some would pass the thumb nail test, some not, but at target velocity mentioned by the op leading has never been an issue. I gas checked the few I want to shoot a little hotter. Fooled around with wax gas checks for a few years with mediocre results.

 

[JPIMBO]

I sure would like to pick your brain sometime @whughett . lee says its pressure we need to be mindful of but it leads to harder and harder. Does that formula work for a special case like a pistol caliber in a rifle? I like that optimum idea. My alloy needs tin, but with just 2% antimony their brittle.

 

[Jesse Heywood]

http://www.lasc.us/Fryxell_Book_Chapter_3_alloySelectionMetallurgy.htm

Bullet hardness is WAY overrated. Elmer Keith did all the development work of the 44 Mag with a BHN 11. Read that twice, let it sink in. That was what was considered "hard cast" of the time.

Now we see commercial bullet casters using alloys of up to BHN 24 with crayon lube and people wonder why they are getting leading.

Bullet fit is MUCH more important than lead hardness.

1. Slug your bore. Measure the slug.
2. Now measure your cylinder throats. The throats should be slightly larger than the bore in an ideal situation.
3. You want bullets that can be pushed through the cylinder throats with light pressure.

I could not have stated this any better!

Does that formula work for a special case like a pistol caliber in a rifle?

Bullet hardness applies the same, be it handgun or rifle. Follow the formula.

I am a fan of wadcutter bullets. There are times when I like to push them to high velocities. For 357 magnum I have played with high velocity. One load that I have used comes from the Alliant 2004 manual. Powder is Unique, 148 grain wadcutter. 5.8 gr., 1,344 fps to 6.4 gr., 1,465 fps, 33,800 PSI. I just loaded some wheel weight lead, age-hardened. Should be 12-14 BHN, powder coated. Several years ago I tried this with commercial lead, lubed bullets with light leading. Only problem now is waiting for the Kung flu problems to pass to where I can be comfortable to return to the range.

 

[whughett]

Lyman’s #2 Alloy BHN 11 92%lead6%Antimony2%Tin

Linotype. BHN 22.
84%lead12%Antimony4%Tin.

Looking thru Lyman’s 3rd edition Pistol and Revolver Handbook all loads listed using cast bullets are Lyman’s #2 Alloy except 38 Special, 357 Magnum and 44 Magnum which are listed as cast bullets using Linotype.

Of interest to some perhaps but as noted before all the lead I use today is an unknown alloy. Hardness unknown. Only factor that may indicate lead content is how close to the actual bullet weight the mold will throw. Light would mean a harder bullet. (less lead). Heavier, more lead, softer bullet. Molds are calculated to throw bullet weights using the specific alloy they were designs for.

Crap I’m giving myself a headache. If it shoots use it, if not remelt with lead from another source.

 

[Catpop]

I like .002 -.003 over bore size and brn 7-11 for my 357 and 44 mag.
I’ve pushed them to 1300 conventual lube with no problems
Jmho
Good luck

 

[243winxb]

Depends on how the BHN is reached.

Basic Rules for Hardening Lead-
For every 1% additional tin, Brinell hardness increases 0.3.
For every 1% additional antimony, Brinell hardness increases 0.9.
For a simple equation,
Brinell = 8.60 (Antimonial Lead) + ( 0.29 * Tin ) + ( 0.92 * Antimony )

https://www.rotometals.com/bullet-casting-alloys/

Lyman -

While antimony is used to harden the bullet, the mixture of tin is critical, for while antimony mixes with lead in its molten state, it will not remain mixed when it solidifies. If tin were not added, we would have pure antimony crystals surrounded by pure lead. A bullet of this type , while it feels hard , would certainly lead the bore and eliminate all potential for accuracy.. In a lead-tin-antimony mixture, the antimony crystals will be present just the same, but they will be imbedded in a lead-tin mixutre. As the bullet cools the tin will form around the antimony-lead keeping your bullets from leading the bore.

 

[Walkalong]

https://www.thehighroad.org/index.p...-powder-load-vs-leading.806469/#post-10299681

 

[DukeConnor]

I try to cast all my handgun bullets around 11-12 BHN. I powder coat and have not had any leading problems.

I am not loading fire breathers.

 

[whughett]

I’d still like to know how all the folks discussing lead hardness even know what that hardness is beyond the specs for a purchased bullet or lead. Many folks cast bullets from scrounged lead. Alloy unknown with out some pretty sophisticated and expensive equipment.
It’s all guess work otherwise.

 

[kcofohio]

I’d still like to know how all the folks discussing lead hardness even know what that hardness is beyond the specs for a purchased bullet or lead. Many folks cast bullets from scrounged lead. Alloy unknown with out some pretty sophisticated and expensive equipment.
It’s all guess work otherwise.

Over at castboolits.com, there is a thread or 2 that covers using sets of pencils that help a person know their lead hardness. It's quite an interesting read.

 

[Texas10mm]

The pencil test is quite accurate.

 

[kmw1954]

I’d still like to know how all the folks discussing lead hardness even know what that hardness is beyond the specs for a purchased bullet or lead. Many folks cast bullets from scrounged lead. Alloy unknown with out some pretty sophisticated and expensive equipment.
It’s all guess work otherwise.

I too load from the weird science/voodoo method.

Most of what I am using as a base metal is recycled indoor range scrap of unknown content. After I render it down I have been testing using the cheap "pencil hardness" test as described on Cast Boolits. This has been forming muffin pucks that are about a BHN of right around 8. Stuff is pretty soft. I then found some print type on ebay, also of unknown content that was listed as linotype but I believe is harder and is probably monotype and may even be Foundry type. as I have melted some into small ingots and I can't scratch this stuff with even the hardest pencil. But after it cools and hardens it has a flakey/crystal look to it. It is not shiny so I don't know if that is from the antimony not reaching full temp.

Anyways I have been taking the range scrap and adding 10% of this type alloy to it and it is reaching about 10 BHN and the bullets dropped are significantly lighter in weight.

 

[kcofohio]

The pencil test is quite accurate.

Once things start opening up, I plan on stopping at Staples to be me a set, the Staedtler brand.
Right now I can only assume that my lead is around 11 or 12 Bhn. 95-3-2

 

[whughett]

I too load from the weird science/voodoo method.

Most of what I am using as a base metal is recycled indoor range scrap of unknown content. After I render it down I have been testing using the cheap "pencil hardness" test as described on Cast Boolits. This has been forming muffin pucks that are about a BHN of right around 8. Stuff is pretty soft. I then found some print type on ebay, also of unknown content that was listed as linotype but I believe is harder and is probably monotype and may even be Foundry type. as I have melted some into small ingots and I can't scratch this stuff with even the hardest pencil. But after it cools and hardens it has a flakey/crystal look to it. It is not shiny so I don't know if that is from the antimony not reaching full temp.

Anyways I have been taking the range scrap and adding 10% of this type alloy to it and it is reaching about 10 BHN and the bullets dropped are significantly lighter in weight.

Thanks for that. Live and learn.

 

[forrest r]

Lyman’s #2 Alloy BHN 11 92%lead6%Antimony2%Tin

Linotype. BHN 22.
84%lead12%Antimony4%Tin.

Looking thru Lyman’s 3rd edition Pistol and Revolver Handbook all loads listed using cast bullets are Lyman’s #2 Alloy except 38 Special, 357 Magnum and 44 Magnum which are listed as cast bullets using Linotype.

Of interest to some perhaps but as noted before all the lead I use today is an unknown alloy. Hardness unknown. Only factor that may indicate lead content is how close to the actual bullet weight the mold will throw. Light would mean a harder bullet. (less lead). Heavier, more lead, softer bullet. Molds are calculated to throw bullet weights using the specific alloy they were designs for.

Crap I’m giving myself a headache. If it shoots use it, if not remelt with lead from another source.

On what pages are the lyman #2 and use linotype for 38spl/357/44mag????

I know on page #97 (3rd edition) clearly states 95/5/5.
Lyman's 4th clearly states 95/5/5 on page #23

On both pages of the lyman books it state's (lyman #2)

 

[whughett]

Are you quoting the same book.

Admin I’ll delete if this violates any copyrights.
Edit:
Oops forgot the photo.