What harm is in high Bhn numbers?

[jacpot]

This may be a very elementary question to some of you, but what is the biggest concern with the Bhn hardness of cast rounds?

I've been reading a lot about it, see it mentioned a lot on this site, and even fooled around with a home-made tester. But I'm still not clear on the detriment of having "too hard" of a bullet.
This past weekend I loaded up a few rounds of some .452 that were my very first bullets cast. very hard to the fingernail, and barely scratched with a leather awl.
I fired them from my 1892 Rossi and all seemed well. they Chrono'd at ~920fps with 5gr of Bullseye, very tight & consistent pattern at 25 yards.

One of the rounds I fired must have glanced off a tree behind the target and went skyward as I heard a "Sweeerzzzz" sound coming from the sky and landed a couple dozen yards away. If I hadn't heard that round hit the ground I wouldn't have given it much thought, But I pulled out my metal detector and found the round and was surprise to find it was nearly perfect except for very slight rifling lines.

Shocked that this ricochet had not deformed the bullet at all makes me concerned there could be other issues that this "Newbie" doesn't understand about reloading and should be aware of. So how hard is too hard?

Any advice or comments welcome.

Thanks - Jacpot
:coffee:

[HORNET]

Depending on what you're trying to achieve, there might not be any problem with boolits that are as hard as you can get.
There are a couple of downsides though.
1.) Along with extreme hardness frequently comes a loss of ductility. I have seen reports on here from people that have used boolits so hard that they cracked during crimping or even gascheck application. A little too much of a good thing.
2.) If there are some dimensional and/or alignment issues, sometimes a softer boolit can obturate and provide better accuracy than a harder boolit. This is frequently reported with light loads in rifles and with moderate loads in handguns.
3.) For hunting use, many people on here seem to feel that some expansion is a good thing. Very hard boolits probably won't expand at all and may just act like full jacketed. Bullshop's Rule says that, for expansion, the impact velocity should be above 100 X the BHN of the boolit (until you get to about 1800 fps or so).
There are probably a lot of other issues that others will mention, but that's a start.

[462]

jacot,

Too hard is usually an invitation to leading.

Are your boolits gas checked?

Did you check the barrel for leading?

How many are "a few rounds"? Sometimes, the effects of leading won't become apparent until you've fired 25 or more rounds. Shoot 50 rounds per session and see what happens to the size of the groups and what the barrel looks like.

[jacpot]

jacot,

Too hard is usually an invitation to leading.

Are your boolits gas checked?

Did you check the barrel for leading?

How many are "a few rounds"? Sometimes, the effects of leading won't become apparent until you've fired 25 or more rounds. Shoot 50 rounds per session and see what happens to the size of the groups and what the barrel looks like.

That day I shot 60~70 rnds from a rifle I got for Xmas (only had it a few days)
No gas check (Lee 452-255 RNFP mold)
the Chrony (another Xmas present) for all those rounds was between 881 to 948fps which I thought was pretty consistent for my first lot of hand-cast and reloads (remember, I'm a newbie to this)
Afterwards, I looked down the bore before cleaning and there was very few "particles" per se.
group size? hard to say for the first 10~15 rnds as I was trying to sight it in, but after that I was holding a 1.5"~2" group (iron sights @ 25yrds) but still shooting 2.5" high.

Leading? I'm not sure what I'm looking for if it was there? what's an indicator of leading?

Thanks

[docone31]

I mix a small percentage of zinc in my melt to toughen them up.
I have found, that you have to stir it. I have had that cracking that was mentioned.
With my loads, and pan lubeing, I have not gotten any leading. I would not reccomend Tumble lubing, or light loads.

[454PB]

I disagree on the obturation theories. If the boolit is cast large enough, it doesn't need to obturate if the firearm's dimensions are correct. Obviously. a revolver with .451" throats and a .453" bore is going to lead without (and maybe even with) obturation.

Extremely hard boolits will shatter on hard objects, but I've never seen one do that in meat.

[376Steyr]

Obturation = "to stop up;close". This refers to the bullet deforming under pressure to seal the barrel as the bullet travels down the bore. An undersize, excessively hard bullet (ie high bhn) will not completely seal the bore, allowing some hot gas to leak around the bullet, and may also fail to get a good grip on the rifling. This can result in poor accuracy and "leading". Leading is the excessive depositing of lead in the bore. Think rubber skid marks on a paved road. Juggling Bhn, bullet diameter, bore size, throat size (in revolvers) and lube type is all part of the fun of this hobby. Welcome to the club!

P.S. And if your loads are safe and accurate enough now, don't let the technical stuff spoil the fun of shooting!

[runfiverun]

first off as a proponent of soft alloys here goes.
you do not need to bump up a boolit you just need one large enough to fill your bore.
shooting a levergun is much like shooting an autoloader.
you only need a boolit to do a couple of things one is chamber the other is engage the rifling properly.
a hard boolit accomplishes this easily enough if the size is large enough.
the most negative things i can think about hard are.
they cost more.
they have more antimony in them which is abrasive.
i don't hunt with a hard boolit nor shoot them any harder then necessary but if it's what you have use it.

[Marlin Hunter]

For wheel weights, I don't think you can get the boolt too hard. But with other lead alloy, you might be wasting money for the extra antimony and tin that you don't need. I have read of boolits that fragment on impact if they are very hard. That wouldn't be good for hunting. otherwise I don't have much experience with different harness of boolits. I have found that in a 45 ACP, making a boolit harder is not the cure for barrel leading. I have not experimented further.

[jacpot]

Thanks for the advice.
So I take it not much harm in a really hard bullet except that it won't expand enough for hunting.
I was more concerned with higher pressures and so on but it sounds like as long as it makes it out the barrel and keep the powder charge light it should be okay.

[runfiverun]

run them on up take your loads up.
when you get a 50 yd zeero your sights will react better to changes.
one click up for a 100 yd zero from a 50 yd zero will be about right then just leave it at the 100 yd zero and learn the drop for further shooting.
then if you take the load up more you have a down adjustment for your flatter shooting load.
the rossi will take a full load and your boolit will respond better also.

[sheepdog]

I mix a small percentage of zinc in my melt to toughen them up.

Please, for the sake of those that recycle your scrap, do not do this. no one want zinc in their pot if they arent expecting it. If you need to toughen them up add chilled shot. Adding zinc into the mix will only snowball the amount out there already.

[docone31]

Some of my loads are pure zinc.
They actually work real well.

[runfiverun]

zinc is not a killer to lead alloys,it actually has some benefit to it.
there is more to alloys than tin/antimony.
zinc is available in the form of ww's might as well get used to using it, as thats about all we'll see in the future.

[docone31]

I use zinc. It just has some quirks.
Zinc needs heat. It takes heat to cast. More heat, more degredation of molds, pots, etc.
There was an article in the '70s that worked on zinc castings and had rather good results.
Zinc is lighter, and harder. Presents different operating criterion.
I do not know how Black Powder and Zinc get along. But I do know how my rifles and zinc get along.
I also do not hunt. I am a target shooter. A recreational one at that.
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