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BNH Rating vs CUP and Vel.

Discussion in 'Handloading and Reloading' started by D.B. Cooper, Mar 14, 2019.

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  1. D.B. Cooper

    D.B. Cooper Member

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    I'm looking at loading data for Clays for revolver cartridges (38 spl/357 mag and 44 spl/44mag) for rifle and revolver. I like Clays in my 44 Spl., and I'm getting better results with metering now. Hodgdon publishes data for Clays in all of the above cartridges, so I'm thinking about buying it 8 lb cans now.

    I would like to be able to load both target and defensive loads for both revolver and rifle using the same powder and projectile. The projectiles I'm currently using are cast lead 12 BHN. Missouri Bullet company says they are for 44-40 or modern 44 special velocities. I assume they mean somewhere around 800-900 fps.

    Question 1: What happens if I drive them up to around 1200 fps and about 33k CUP? (top end for both 44 magnum and 357 magnum)

    Question 2: Is there a better hardness rating for my specified purpose? Should go to a harder alloy for the higher velocities?
     
  2. fxvr5

    fxvr5 Member

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  3. D.B. Cooper

    D.B. Cooper Member

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    SMH. How in the world did I miss that? I obviously didn't do my homework. Thanks.

    The only problem with that is they use PSI for their calculation, but all of my data is in CUP, and there seems to be no way to convert CUP to PSI.
     
    Last edited: Mar 14, 2019
  4. D.B. Cooper

    D.B. Cooper Member

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    Sooo... my data is in CUP, however, I can take the formula in that link PSI/1279.8=BHN, flip it to PSI=1279.8(BHN) and get an idea of what the max PSI for that BHN would be. (15k psi for a BHN of 12.) Looking at max SAAMI chamber pressures, 15k is in the realm of 44 spl and 38 spl only.

    Given the other info in that link, about gas cutting and leading, etc., I would need a BHN in the upper 20s for the magnum loads. Which I find odd, because Mo. Bullet's hardest/heaviest 44 magnum WFN (so...hunting bullet) is only BHN 18.
     
  5. Walkalong

    Walkalong Moderator

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    Nope, just a good fit and throats suitable for the bore. We have discussed it a lot here.
     
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  6. Bfh_auto

    Bfh_auto Member

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    The only way you will know for sure is by working up the velocity until you get some leading, then backing down.
    I've run their 125rnfp with 357 data without leading. You might get away with it in 44.
     
  7. ReloaderFred

    ReloaderFred Member

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    A cast lead alloy bullet over about 20 Bhn would be brittle and would shatter upon impact with a hard substance, such as steel or concrete, and wouldn't deform at all in soft targets. That's why almost every commercial bullet caster sticks with a Bhn of around 18 as their hardest bullet. Of course, there are a few exceptions, but they're not commonly used for what we do.

    I've found a Bhn of 12 to be almost ideal for most of my handgun casting, with the hardest I cast at Bhn of 15. If I need anything to be pushed harder, like in full boat magnum rounds, then I use a gas checked bullet.

    Hope this helps.

    Fred
     
  8. Random 8

    Random 8 Member

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    I have run BHN 12 bullets to near top speed in .41 Mag and .357. You WILL get leading, but you will also get deformation on soft targets. For a personal defense situation, I'd think with the 6 shots you'd get off, leading would be a non-issue. A soft wadcutter running hot is a proven defensive load at close range. If bears are on your menu however, I'd consider penetration to be a trump card and go hard and heavy with a large metplat.

    You could also look into the Hornady lead hollowpoints. I've found their .357 158 to expand very well at .38 Spl speeds, and extremely well at .357light over a full charge of HS-6.
     
  9. LRDGCO

    LRDGCO Member

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    No cast handgun bullet need be harder than BHN 15 and, generally, no harder than BHN 12. In fact, overly hard commercial cast bullets ill matched to lube are more of a problem than softer bullets. BHN 12, with proper bullet fit, will be fine for 1200 fps. But, please don't take my word for it. This is an excellent read on the subject by an acknowledged expert (brought to our attention in a separate post yesterday by member bds. Thanks!):

    http://www.lasc.us/Fryxell_Book_Chapter_7_Leading.htm
     
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  10. WrongHanded
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    WrongHanded Contributing Member

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    Perhaps try the BHN 12 projectiles you have at your intended loading with the revolver, and see if you get leading. If so, you can be glad you tried them in your revolver first, because I've found scrubbing lead out of a rifle barrel much more tiresome. If they work okay in the revolver, try the rifle.

    However, I use cast lead with a BHN of 17 or 18 at magnum velocities, and have no experience doing the same with lower BHN.
     
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  11. drband

    drband Member

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    I’ve run full power .44magnum H110 loads with MBC 240gr coated lead SWCs. The 18BHN were good, but the 12BHN were better!

    Neither produced leading in my SBH.

    YMMV
     
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  12. MaxP

    MaxP Member

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    That would depend entirely on usage.
     
  13. D.B. Cooper

    D.B. Cooper Member

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    I was thinking it would come to that. I always try to learn the easy-from the experience of others.

    That said, I noticed some leading just in the breach end of my revolver last week. First time ever. I don't know if it's from my normal loads or from the slightly faster loads I was experiments with last week. (I added 0.2 grns of Clays.)
     
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  14. D.B. Cooper

    D.B. Cooper Member

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    The most telling thing to come out of that link:

    "...fast powders for light target loads (e.g. Bullseye, W231, HP-38, AA #2), medium burners for standard pressure loads (like Unique, Universal Clays, AA #5), medium slow powders for +P loads (powders like HS-7, Blue Dot, AA #7) and slow powders for full-house magnum loads (like W296, H110, 2400 and AA #9). Match the powder to the pressure curve. The use of fast powders for higher than normal pressures with plain-based bullets can cause bad leading, due to the very rapid pressure rise time early in the P-T curve leading to high pressure faster than the bullet alloy can obturate in response to the pressure, and as a result severe gas cutting can result. "
     
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  15. LRDGCO

    LRDGCO Member

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    You are, of course, welcome to your opinion. Despite it contradicting experience, metallurgy, and physics...
     
  16. MaxP

    MaxP Member

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    My opinion is born of experience handgun hunting and when you are facing animals that weigh more than 1,000 pounds, where penetration is at a premium, and your bullet needs to maintain its nose profile to track straight, deep and to produce the largest wound channel possible, I prefer a harder bullet - based of course on experience, metallurgy and physics with a heavy dose of terminal ballistics mixed in. But of course if you are running low velocities it’s not as important. Having said that, I have pretty much written off cast bullets for animals that significantly outweigh me as I have seen way too many failures with cast bullets of every ilk. Make mine a monolithic solid, that won’t deform on bone.
     
    Last edited: Mar 14, 2019
  17. Tradmark

    Tradmark Member

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    I would just shoot a copper solid. That is too much mental masturbation before even getting to loading or shooting. The simple physics of it all and my experience of it all is they will all freaking deform if hard bone is hit.
     
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  18. ArchAngelCD

    ArchAngelCD Member

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    You may be setting yourself up for problems. Clays is a very fast powder and will produce higher pressures at lower velocities than with a slower powder. You won't want that especially for the defensive loads you mentioned in the OP.

    Using a medium speed powder like AA#5 will allow you to generate the velocities necessary to reliability expand a SD bullet yet keep the pressures lower to prevent leading. A good fit along with powerlessness will keep your barrel nice and clean. I would move off Clays especially since its been known to spike pressures when approaching the top of the pressure range.
    .38 Special SD ammo: AA#5, HS-6, True Blue, BE-86, Power Pistol, W244 and the like.
     
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  19. CraigC
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    CraigC Member

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    That's an interesting absolute statement and patently false. If all you're doing is punching paper or shooting deer, then 12-15 is fine. However, as game weight and/or velocity increases, you need a harder, tougher bullet. Even then, cast bullets have their limitations.
     
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  20. D.B. Cooper

    D.B. Cooper Member

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    Just out of curiosity, Craig, what projectiles are you using to handgun hunt those big critters with?
     
  21. LRDGCO

    LRDGCO Member

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    Yes Craig, for the 3 people in the world that want to shoot a cow with with a cast bullet from a hand gun, perhaps harder than BHN 15 might be useful. The rest of the world would generally tend to use a bullet more suited to the task...
     
  22. WrongHanded
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    WrongHanded Contributing Member

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    Or maybe for woods defense where there are moose and bear.
     
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  23. LRDGCO

    LRDGCO Member

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    Neither of which require anything harder than BHN 12. The Buffalo herds were slaughtered with bullets no harder than BHN 8, at the most.
     
  24. MEHavey

    MEHavey Member

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  25. MaxP

    MaxP Member

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    Shooting cows? Can I ask if you hunt? If so, with what and what game do you mainly hunt? Trying to understand your perspective.

    Clearly if you are only shooting deer and limiting your velocity, softer bullets won’t be a hindrance. When moving up to larger animals, where your bullet just might encounter heavy support bones, harder is better.
     
    Last edited: Mar 15, 2019
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