I am looking in to the BHN scales. I am not a cast guy first and formost, but want to be. Don't want to start molding my own, but buy. Anyway, whats the deal with it? Laser cast said they measure 25BHN. From what I gather, thats very hard.
I assume a bullet 21BHN will not outpenetrate a 25BHN bullet if all things equal. But, where's the limit? I mean I see brittleness is a factor. I guess what I am asking is will accuracy decrease with a super hard cast? Or only some cases? Is there benefit to real soft cast in the 14BHN range?
Bigcountry - the hardness of a cast bullet, from what I have seen over the past 30 years, is quanitified more from the perspective of internal matters than terminal ballistics. Harder bullets can be driven faster without leading, but have less ability to "upset" into the lands/grooves at lower pressures. Kind of a balancing act. You generally want a softer bullet for .38 Special target loads - but not for .454 Casul. I don't recall ever hearing of a hardcast bullet breaking apart on game from being too brittle, though. Hope that helps. Roskoe.
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A man has got to know his limitations . . . . .
I see this question as one VERY hard to answer for EVERY case.
Here's the problem. For example, what works in a 30 cal doesn't work the same in say a 44 cal!!!
I've cast thousands and thousands of bullets, and i've found it "easier" to settle on a general hardness that i have found to work well, and then ajust "to the bullets" that drop from the mould by working loads up for those bullets just like i do handloading with jacketed bullets!!!
How hard is my alloy for casting bullets??? Well, i like the bullets from the mould to be "just soft enough" so that i can put a scratch in them with my thumb nail!!!!
I mix all of my scrap lead in a big cast iron dutch oven and alloy it to my likeing, then i cast it all into "ingots" that i remelt later in my 20 pound lead pot. When "that" lot of ingots is used up, i make up a new batch. This means i have a dutch ovens worth of bullets of all the same alloy. This has been working for me for many many years now.
Thanks guys. I don't think I want to try my hand at casting myself. Just curious on what bullets to buy for my application. I have a 1895 Marlin 45-70 and figured I would try some 350gr or 405gr cast. For the 405gr cast I want of course great accuracy (microgroove barrel) and great penetration. Trying to figure what to buy.
Just a warning - I did not get very good accuracy out of my 1895 Marlin with cast bullets. I understand the micro-groove barrel is designed to be used primarily with jacketed bullets. Maybe if you slow them down a bunch . . . . . I think I would look at some economical jacketed bullets first.
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A man has got to know his limitations . . . . .
As DM said, there is no hard and fast rule to lead hardness.
Ask 10 bullet casters the same question, you'll get 10 different answers.
If a bullet is too hard, it will lead a barrel if not driven fast enough because it won't obturate and hot gasses willl pass by it.
A soft bullet ie, straight w/w BHN ~15 can be driven up to 2000 fps without leading if it sized correctly and the lube is right, others will say that you need to shoot lead with a BHN >30 to shoot at these velocities, but the softer bullets work for me in a 30 bore just fine. On the other hand, I find my 1911 likes a harder bullet, so I drop my hot .452 bullets in a bucket of water to harden them to the point where I have no leading problems.
As someone else said, try slowing them down in your marlin. You don't really need to push a 400 gr bullet very fast to make it an effective game killer.
A bullet with a BHN of 25 probably isn't going to expand much if at all on game. Maybe not a big deal with a .458" bullet, but it is a big deal with anything 35 cal and under. They guys that use cast bullets for hunting want the softest bullets as possible, with w/ws being at the hard end of the spectrum.
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Most commercial cast bullets are TOO hard, in my opinion and experience. Hard for the sake of hard is not a good way to go. Appropriate hardness is much better.
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Just a warning - I did not get very good accuracy out of my 1895 Marlin with cast bullets. I understand the micro-groove barrel is designed to be used primarily with jacketed bullets. Maybe if you slow them down a bunch . . . . . I think I would look at some economical jacketed bullets first.
Microgroove barrels will handle cast bullets just fine...just need to meet some certain conditions.
1. Bullet should be .001 or .002 over groove diameter...your .45/70 shooting .457 cast should do fine with cast bullets at .458 or .459.
2. Should be gas checked
3. Should be appropriately hard. IME, about WW with enough tin to allow good fill out.
Gas checked cast bullets would work fine I'm sure . . . . they are pretty much jacketed bullets with a short jacket. For me, however, for the additional effort and expense to put a gas check on a regular cast bullet - I would just get some inexpensive jacketed bullets in bulk. Midway had a sale awhile back on the 405 Remingtons that made big bore plinking a fairly reasonable pastime. Roskoe
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A man has got to know his limitations . . . . .
Cast hardness rules?
