Descrepensies in BHN with bullet casters

[poules'deau]

Hello Verel,

Need your help.....

I recently got one of your lead hardness testers and it has been an eyeopener for sure.  Almost none of the cast bullets I've checked come out to what the casters claim.

In particular, I have been trying to buy Keith style 44/45 with a max of 10-12 BHN.  I have bought some advertised at 10-12 BHN but there not even close at 15-16 on the scale.  When questioned, they tell you the mix of linotite, solder, wheelweights  and lead they use etc but this means nothing to me.  

Am I asking for something that can't be done?  What is it with getting the correct hardness?  And how much practical difference does 3-4 BHN make?

Thanks
Jim

[Veral]

  You are correct in saying that most commercial cast bullets don't deliver the advertised hardness.  This because the manufactures don't have a hardness tester, don't understand the variables which dictate what hardness will be with any given alloy, and simply take the lead suppliers statement about hardness as fact.
  For revolver use hardness is important in regulation of bullet upset and deformation inside the gun. If bullets are undersize for a particular gun, they MUST be soft enough to upset a part of the bullet base and seal off blowby gasses to prevent leading.  But accuracy cannot be tops if bullets are undersize, as only the base upsets, and the undersize nose area portion can lean off center and out of balance.             If bullets fit the cylinder snugly, blowby cannot wipe lube from the groves, even if the bullet doesn't expand under chamber pressures.
  Therefore.  Soft bullets are only needed if they are undersize, and, softness should be matched to the load of interest.  i.e. Soft enough to upset and get the mandatory seal, yet not so soft that they swell out into the forcing cone enough to deform the bullet, (hurts accuracy) cause lead spitting, and even cracked forcing cones.
  About 12 bhn will be obtained with air cooled WW alloy, and is very suitable for low velocity revolver loads, of 1000 fps and less with decent lubes. Water quenching will bring hardness up to about 20 and improve accuracy dramatically if bullets are fitted to the gun properly, and allow full magnum velocities with far superior accuracy and leading control.

[azvaquero]

Hi Veral --

Just a question relating to this topic.  I have had terrible leading problems shooting the 45 Colt (I have 5 of them).  I have checked throats, some are .452, .453, and .454.  I have sizing dies for each of these sizes.  I have tried all sizes in all guns (i.e., in my .452 throats, I have tried .452, .453, and even .454, and so forth).  The only thing that finally stopped leading was when I went up to 10 grains of Unique.  9.5 grains leaded just a bit, but below that it was significant.  The bullets are around 13-14 BHN per your hardness tester (air cooled WW).  They seem to need to slug up.  Leading is not only in the barrels but in the throats and leades as well.  Pressure, not size, seems to be dictating whether leading will occur or not.

I have had similar experience in my other guns.  In 44 mag, shooting 15-16 BHN bullets, I get leading at low pressures, but none at higher pressures (such as 18-19 grans 2400 behind a 240 grain bullet).  Throats are .433, and I shoot .433 bullets as they drop from the mould. 

Can you explain this? 

[Veral]

  Since you have tried oversize bullets and still get leading, I know that blowby in the cylinder throats isn't stripping lube from your bullets, so there is only one other problem area that I can think of.  Lube breakdown, which doesn't seem right in light of the fact that leading stops with higher pressures.  Yet, in the 20 years since I developed the LBT lubricant formula, not one person that I can recall has complained of the problems you are having, while hundreds of customers have bought it for stop the problems you're having..  Many who don't cast have stopped it by smearing only a film of LBT Blue soft OVER the existing commercial lube, by wiping it on with a finger.

[azvaquero]

Veral --

I read your post, and have a little more information:

I am getting heavy leading in the throats themselves, and even in the leade (stepdown) area between chamber and throat where I wouldn't think the bullet would even touch.  The barrel leads, but much less than the throats.  Therefore, it appears to me that there IS blowby occuring.  By the way, everything is smooth as the gun I fire the most has been firelapped. 

Blowby seems especially likely as, as you point out, leading decreases altogether as pressures are increased.  I have a whole lot of lube I am trying to use up which is from Ballisticast.  This is on the hard side, but is still softer than what I was using before (Magma).  If you still think that lubrication is the issue, could it be that the lube is so hard that it does no good at lower pressures and therefore I get no lubrication in the throats?  Or do you think something else is at fault?  If so, what would cause the leading in the leades between the chambers and throats?  Thanks.

[Veral]

  I'm more sure than ever that lube is your problem.
  From all I can learn, most so called cast bullet lubes are just wax's formulated primarily to apply easily and stay on the bullets, not to give the ultimate in leading protection and accuracy, or chamber pressure reduction.
  Back in 1981, when $30,000 was my life savings, I spent it all on cast bullet lube development, and the formula I came up with works better than anything else I've tried, in handling the above problems, as well as application ease and staying on the bullets.  In fact the only customers who report something better are a few cast bullet benchrest rifle shooters who have special formulas tuned specifically for their purpose.  (I believe the same results is obtainable by using LBT lube and adjusting the amount used, filling more or less lube grooves as required for the ambient temperature and velocity of interest.)
  My advise is to try some LBT lube.  If you find it far superior, and still want to use up the large quantity of wax that you have on hand, melt them together 50-50 or even less LBT, and try the performance.  LBT lube is good enough that only a thin film of blue soft can be smeared over junk lubes and cure most handgun leading ills.  If you try the mixing trick, start with just a small amount, a few grains fo each weighed out in a powder scale, to see how little LBT you can get by with and use the most of what you have.  Get the Blue soft for this purpose.  There my be lubes out there which LBT won't mix with, but I don't know of any.  You'll learn without a great loss if you only melt down a little of each.
  By the way.  I thought I would get rich with my lube formula, but believe it took at least 10 years to get the invested money back!  There were many new lubes coming out at around that time, and almost all have gone under.  For most lube makers, it's a necessary part of their cast bullet business, with little profit.  Customer ignorance and, or, confusion over what's available allow continued sales.  One gets sick of experimenting, REAL FAST! 

  Please read the question Throat, nose and front band relationships for more information .