12BHN vs 20BHN in the 45-70 Bullet Performance?

[BKS]

Please forgive my lack of knowledge.

I know that a 12BHN boolit is softer than the 20BHN one.

Would the difference in hardness affect accuracy?
Ie- load the 12 and 20 to same velocity, could you expect the same level of accuracy?

Would the 12 be a good deer bullet (390gr WFN PC & GC)

Loaded to the same velocity I assume the harder bullet would penetrate deeper.

Thanks in advance.,

[Larry Gibson]

Would the difference in hardness affect accuracy?
Ie- load the 12 and 20 to same velocity, could you expect the same level of accuracy?

At TD level I velocity there wouldn't be much difference in accuracy if any. At level II higher end velocities the 20 BHN alloy will generally give better accuracy. At level III velocities the 20 BHN will give the best accuracy.

Would the 12 be a good deer bullet (390gr WFN PC & GC)

Yes

[35 Rem]

I shoot bullets that are no more than 10 BHN at 2,000 to a bit over 2,100 ft/sec in all my deer rifles with no problems associated with hardness. My rifles consist of 7.62x39, 30-30, 32 Special and 35 Remington. Not a 45-70 but that doesn't much matter if alloy hardness is the subject. I know the conventional wisdom is that a 45 caliber bullet doesn't need to expand as much as a smaller bore but imo some expansion is always a good thing as long as you still get the penetration required. And when it comes to deer hunting with a 45-70 you know you are going to get enough penetration regardless of what you shoot out of the rifle.

[Tripplebeards]

I waited to reply because I just went through this with another post recently but my hardest hunting alloy is 10.5 bh and that’s at 2100 fps with a HP. I use 7.5 bh under that velocity. The only thing I would use 20 BH for is shooting a charging elephant in the brain because there’s gonna be almost no energy, transfer and expansion on that hard alloy unless it hits something as hard as a brick wall.

So do your question the 20 BH will hold together and penetrate deeper but they’ll also be almost 0 energy transfer unless something hard is hit. It’d be like shooting a full metal jacket or an arrow with a field point through a deer with a broadside heart and lung shot. You’re at least getting in the right direction with 12 BH but imo you still need to go softer for hunting.

[cwlongshot]

To give you scale, Dead soft or Pure lead, is accepted to be about 5 BHN.

A very hard bullet will me 20+ BHN.

ZINC IS ABOUT 43/45 BHN

Copper jackets are about 36 BHN

CW

[Bass Ackward]

Depends. You are launching a projectile into turbulence caused by air at the sound barrier. That requires that air flow be established before the base of the bullet exits the barrel and why it needs to break square. It’s all in the launch. This is why 22s can be launched accurately at higher velocities than 45s. Hollowpoints establish this the fastest, flats take the longest requiring heavier weights. So logically, meplat size, rifling height, bullet balance (deformation) elevation, humidity, and the biggest variable, temperature cause of your lube. Bottom line, you have to ask the gun and the target.

[ChristopherO]

I cast the 420 grain WFN GC lubed .460 boolits for the 45/70 out of range scrap. That is on the soft side. I've shot them out of the Marlin 1895 CB as high as 2,000 fps and the factory supplied Marbles open sighted accuracy was certainly good enough to hunt deer at 100 yards. But the hard plastic buttstock had no forgiveness so I toned it down to 1,600 fps and switched out to a Skinner Alaskan Peep. Accuracy is even better. Possibly because I am not being kicked by an angry mule every time I pulled the trigger.

As mentioned above, I like expansion, even for a WFN projectile. It doesn't make a mess, but it does do its job without hesitation. I've captured these perfectly mushroomed between 4 to 6 water filled gallon jugs at 100 yards consistently. The very hard cast boolits I've used for target practice at lower speeds zip through 9 water filled gallon jugs at 100 yards without stopping. When found in the backstop dirt they look nearly unused, except for the rifling marks. The effect on the first couple of jugs are quite noticeable for the two projectiles, as well. The softer cast is much more spectacular.



Now that I've installed a scope on that rifle 200 yards is easily achievable, if I know the dope well enough in the field. On paper the holes printed well within the vital region shooting off sticks. This year's goal it to document exactly which hash line in the scope is needed for 150, 200, and even beyond, because I know the rifle and the boolits are capable of it. Then I will probably continue to kill deer with it at about 100 yards, as seems to be the norm.

[Bud Hartrampf]

ive killed deer, bear and caribou with 500gr 21BHN bullets, out of the 45-70 and muzzle loaders. if your going to go hard, you need a flatter melplat then if you soft. in heavy buck brush and small trees, harder seems to work better at plowing through it. with that said, softer works for all bullet types better, depending on where you live and what can kill you.

[Bigslug]

Larry's spot on. If you're looking at the hotter levels of speed in the 1886 Win / Marlin 1895 or Ruger No.1 load charts, you're going to be better off with the harder bullet, and you should not expect expansion. Since you're running a GC WFN design, that should be fine.

12 BHN should get you up to around 1400-1500 fps or so nicely. Expansion. . .maybe?

Remember that most of us don't have to get up in the morning to shoo BISON out of our petunia patch because slow-moving, @10 BHN .458" bullets killed them all in the 1870's. We don't need to overthink the penetration topic for deer.

[Sgt H]

For deer my favorite boolit is is the Lyman/Gould 457122 HP cast out of 20/1 about 8bhn. I load these to about 1500fps and they work well on deer. Expand very well, usually the front half (depth of the HP) fragments creating a quick kill and no leading. My long range match boolits I have been using 96/2/2 about 11bhn driven to 1300-1350 and no leading.

[HBAR2989]

I cast 350 grain Ranch dogs out of wheel weights. I don't know how fast they are going with 46 grains of R-7, but they group great at 100 yards out of my 1895 GBL. Everything I've shot hasn't taken more than a dozen steps, most go straight down. I don't worry about expansion personally.

[gumbo333]

If anyone cares, I’m certainly not a student of energy dump or turbulent or whatever. Shot several white tails with my 45/70 Henry. 405 cast either HyTek or PC that I purchase. They all are WFN, and most places sell them pretty hard, 18 - 22 bhn. Velocity just above mouse fart, or slow trap door speed (1000fps or less). They work. Yes the boolit goes thru the deer, sometimes stem to stern, but the deer are usually DRT or just 2 or 3 steps. All have been shot at 75 yards or less. I’ve never recovered a boolit. I guess the energy got dumped somewhere. Where it wasn’t is my shoulder. And they have been extremely accurate with Red Dot, Blue Dot and Unique.

[JonB_in_Glencoe]

I'm not really sure if 390gr or 405gr is big enough for white tail deer.

[TurnipEaterDown]

You decide if you need a soft nose, but I decided it wasn't worth my time:

321976

44 Rem mag test I conducted.
Upper water saturated phone book was hit twice w/ Accurate 43-280G which I designed.
Once (on the right) with this bullet having a soft nose of ~ 90 grains, loaded to 1440 fps at muzzle, with 25 grains W296 and a WLP primer, same load without soft nose on left. Distance ~ 15 yards. Hard cast produced greater surface opening.

Hardcast bullet was 23-27 BHN (as was base of softnose bullet). Alloy either quenched wheel weight w/ antimony added or quenched “HP Alloy” (made of 5 lbs indoor rimfire/airgun range lead, ½ - ¾ lb 60/40 Antimony/tin, and 1 lb high arsenic shot). Penetration distance of both was ~ 12”

Bottom phone book was hit once w/ 310 LEE (with a soft nose of 90 grains) loaded over 21.5 grains Alliant 300MP and a WLP primer. ~ 1250 fps. Distance ~ 15 yards. Penetration distance was ~ 13”

Soft noses were pure lead -- when cast into a bullet and tested on an LBT BHN tester they read as 5.

Pictures of the bullets after recovery:

321977

Left, hard cast 280 gr. Note plastic deformation of nose showing non brittle nature of this "too hard" alloy when shot into this media. Nose was of greater diameter after impact than body.
Middle Soft Nose 280. Note nose of soft lead sheared away. Leading edge of hard body again deformed in plastic manner.
Right, 310 LEE with soft nose sheared away. GC still attached, surface coated w/ lead alloy (no longer "coppery" on surface).

[Tripplebeards]

Here’s a Lyman Devastor hollow point casted out of 15.4 BH alloy. Shot into water at 1850 fps out my 77/44. Looks perfect …right? Well I quickly learned learned after shooting group of 3 deer with the load within 15 seconds that the hard alloy doesn’t expand on thin skinned deer. Boolit diameter holes in and out of each one. To get expansion on deer like this text book mushroom the alloy needs to be close to pure lead I’ve found out. I learned several years ago that it’s fun to try and catch boolits in various mediums to see what the expansion looks like but there is nothing that comes close to testing alloys vs an actual deer I’ve found out. I have photos of 50-50 10.5 BH alloy and 7.5 40/1 to one that both flatten to almost a penny. They make nice big mushrooms and expand in deer.

https://i.imgur.com/zDmQvvj.jpg

[nidrab]

Here’s a Lyman Devastor hollow point casted out of 15.4 BH alloy. Shot into water at 1850 fps out my 77/44. Looks perfect …right? Well I quickly learned learned after shooting group of 3 deer with the load within 15 seconds that the hard alloy doesn’t expand on thin skinned deer. Boolit diameter holes in and out of each one. To get expansion on deer like this text book mushroom like this the alloy needs to be close to pure lead I’ve found out. I learned several years ago that it fun to try and catch boolits to see what the expansion looks like but there is nothing that compares to shooting into an actual deer I’ve found out.

https://i.imgur.com/zDmQvvj.jpg

Thank you for sharing the picture and your experience for us noobies!

[Tripplebeards]

I’m only one guy with one opinion. Imo you’ll get many other member opinions that say hard non expanding cast is the holly grail. Imo there’s no right or wrong way but you just have to figure it out for yourself. Me…I like super soft alloys so it expands and dump energy so I don’t have to look far for my deer if it even goes anywhere. The expanded bullet should make a good size hole when it exits so in theory you should have a decent blood trail to follow . The derive shot with hard, Cast I never get blood trails or super sparse like one drop every 6 feet…not a fan of that. After I switched to cast hollow points I haven’t even had to track a deer to date…knock on wood. They’ve all dropped in their track so far. My guess is the 15.4 bh alloy I used above would have to shoot a water buffalo between the eyes if I wanted to get a textbook mushroom like that out of it.

[TurnipEaterDown]

Bullets that expand to diameters much larger than unexpanded size, and foreshorten greatly while doing so, have a tendency to loose stability in the path through a target and loose straight line penetration. While perhaps not terribly worrisome on deer, I have seen an over expanded & foreshortened bullet turn 90 degrees in a 250 lb boar, and run along the spine to the back of the head after being shot broadside.

I shot a WT deer in the rear ham once w/ a 475 dia 320 gr WFN launched at 1600 fps, and I could close my fist and rotate it around in the wound cavity - there was nearly no resistance as there was a hole ~ 3 inches in the center of the ham. Tried to give the deer away after skinning, but the other two guys weren't takers...

I have only had a lack of blood trail on a couple deer, and it was when using jacketed.

Not expanding does not mean a bore diameter hole in the target, if done correctly.

[Bad Ass Wallace]

The large boolits were recovered from wild hogs, they are cast 1:40 and run 10BNH.

https://i.imgur.com/cArT9w1l.jpg

[TurnipEaterDown]

Common projectiles are either fin stabilized or stabilized by rotation.
Once a projectile leaves the muzzle of a gun the rotational energy it possesses can only decay, it can not increase (decay is slow in atmosphere, not so much in some other media).
The formula for rotational kinetic energy is KEr = 1/2 I w^2, where I = moment of inertia, and w is a bastardized Omega which represents angular velocity.
Moment of Inertia for a solid cylinder is expressed as I = 1/2 M r^2 (M= mass, r=cylinder radius).

As the projectile expands at the nose Only (to a size greater that the body, like an umbrella), the cylindrical moment of inertia equation isn't applicable, but if the projectile expands so far as to be reasonably modeled as a short fat cylinder, it can be easily seen from the cylindrical formulas that the rotational speed will drop precipitously.
While a shorter cylinder does not require as high of a spin rate to be stable in flight as a long cylinder (Greenhill twist rate formula displays this), some spin is still required. Right conditions, the projectile destabilizes. No question. It is after all simple Physics.
I have personally seen this using a 310 Woodleigh weldcore from a 14 twist 35 Whelen Imp on a Bison. This bullet is not considered adequately stabilized in a 16 twist. It "is" in a 14 at 2250 fps muzzle, so I used it. The bullet expanded to about 0.8", and --- Was found Backward in wound track when recovered. It turned around because it was unstable in the medium it was traversing. This is not conjecture, Art Alphin goes into this in depth in the A Square manual "Any Shot You Want", and goes on to state why bullets that expand dramatically, while retaining weight, and steel jacketed "solids" like those from Hornady, fail to penetrate in a straight line routinely.

Is a deer a Buffalo or Bison? No.
Is a dead animal, dead? Yes.
But this may not reliably happen as I noted from my own personal experience w/ just one Boar of several.

I would rather have a bullet that Always penetrated line of sight. I want what I "see" to be what is impacted, as I "see" the path of the bullet through the animal physiology no matter how the animal is presented.

The pictures I showed displayed a hard cast "non mushrooming" cast lead alloy bullet creating a larger simulated wound cavity in saturated paper than an expanding bullet which would have (at some point) supported a "mushroomed" nose.
Does this Always happen? No, I would say it is Unlikely. It does depend on amount and resistance of media traversed. Degree of nose upset, etc.
Will a bullet shot into wet paper stack look exactly like one shot into a game animal? No, but that is not really what is important to take away from that little test.

What is important from that test is to note that the Surface diameter of the simulated cavity is Greater for the hard cast which kept a wide sharp nose, than the same bullet which had a nose that deformed or "mushroomed". The nose will start deforming directly upon impact (or infintismally before impact due to a sudden escalation of air pressure at the nose due to the air column between the nose and resistant target having to move rapidly sideways to 'get out of the way' -- more so than in flight, in flight the bullet can "stack" air on its nose, upon reaching the resistant target surface, it can not).
The harder, and Sharper, nose created a bigger initial cavity profile (which by the way continued through the cavity).

Fluids dynamics also tells us that Cavitation is Enhanced at sharp edges, whereas a rounded edge promotes less disturbance and less cavitation.
Properly designed, a bullet Can create cavitation of the body elements surrounding the wound track.


So, does a bullet that pancakes with rounded edges kill? Yes, often.
Does it Reliably penetrate in s straight line? No, physics dictates that it will not.

Fluid dynamics will also show that the rounded edges do not affect the surrounding tissue the same way, and this ought to be evident to anyone who has shot a game animal with a RN & sharp edged SWC of the same weigh and initial speed out of something marginal like a 45 ACP. The SWC "works better" on game.
This is why there were also tools sold years ago to put a flat meplat on 22 RF ammunition used for small game hunting.

Would I rather have line of sight penetration always? Yes.
Does physics and cavitation phenomena support the results I have seen? Yes.

As it was told to me when I started a career in testing 3 decades ago: 1000 successes prove nothing. One failure proves everything. This in itself is "taken" from math theory. Getting the right answer proves nothing. Proving the method is what is valuable.

Again, if someone likes and uses soft cast bullets that expand dramatically in a rounded shape, by all means, do so. I know that it doesn't have to be done this way, and there are some obvious benefits to not having a hugely expanded bullet with rounded edges.