To continue the theme of bullet construction/composition from my post yesterday, I wanted to make a separate post regarding homogenous (solid/monolithic/etc) bullets. I was also asked to share this multiple times.
These types of bullets were originally made to fill a simple role and purpose. That being a lead-free bullet, but still be able to expand. States such as California have banned lead in hunting bullets for claimed environmental reasons. Thus came about the solid copper bullets, out of necessity. Necessity is the mother of all invention, after all. Since their release into the shooting/hunting community, folks have discovered how they retain most, if not all, of their weight and penetrate very deep (typically exiting). To the hunter that desires this kind of performance, that's big news. They've gained a massive amount of following due to this characteristic alone. Herein lies the problem. Yes, these bullets do indeed penetrate deep, and at pretty much any impact velocity, but that's not always a good thing. At a high impact velocity- well above 2200fps- they will expand very well and impart a great deal of hydraulic (permanent and temporary cavity) and hydrostatic shock. That being said, shot placement is critical with this type of bullet, as is impact velocity. You must hit vitals, and you must impact no less than 2200fps in order for the bullet to expand ADEQUATELY and to inflict enough hydrostatic shock to knock down the animal. Hydrostatic shock is what transfers to the central nervous system (CNS) and will cause it to temporarily shut down and the animal will go into a temporary coma. It's similar to a boxer getting knocked out in a fight. You still need to inflict enough wounding for the animal to bleed out before it can recover. If there's not enough hydrostatic shock, but still enough wounding, the animal may run, but will bleed out and die eventually. This is a more common occurrence, as you either need to hit an autonomic plexus, or have enough energy/speed on impact to reach out and hit the CNS to shut it down, and that's not always achievable.
To elaborate a bit regarding hydrostatic and hydraulic shock, as these terms tend to get misused/misrepresented:
Hydrostatic shock refers to the effect when shock waves travel through flesh to nerve centers, disrupting their ability to emit electrical impulses.
Ironically, the terms hydraulic and hydrostatic shock are actually misused a lot by both hunters and professionals - including ballisticians working for bullet making companies.
The reason why animals drop instantly with chest shots that do not directly strike the CNS, is due to hydrostatic shock transfer to the spine which passes through to the brain. Any high velocity cartridge along with a good bullet properly selected for the particular animal size imparts over half its energy within the first few inches of penetration, creating a shock wave. This electrical shock wave travels outwards via the rib cage until it reaches the spine and then continues through to the central nervous system in the brain (CNS). The result is an immediate loss of consciousness as the body shuts down for diagnostics (temporary coma).
Along with the loss of consciousness, the projectile has also created a large wound channel, draining all of the body's blood within several seconds. The rapid blood loss and trauma cause death to the animal before it has the chance to regain consciousness.
This action creates the illusion that the projectile has knocked its victim to the ground, killing it instantly, but if it doesn't actually inflict sufficient trauma and blood loss, the animal will recover and often times get up and run. So, it's ultimately best to have both hydrostatic AND hydraulic shock.
So continuing on, a homogenous bullet requires a great deal hydraulic shock (large wound cavity), and ideally a great amount of hydrostatic shock as well, in order to kill the best. A typical homogenous bullet does not shed weight and reach out like a softer, frangible, or even a bonded cup and core bullet. If impact velocity is too low, both hydraulic and hydrostatic shock will be minimal and the bullet tends to produce minimal expansion, or none at all. If you miss vitals, you'll likely not kill the animal and it will get away. If you do hit vitals, but it still pencils through them, you'll typically cause a slow and inhumane death. The animal may still travel far enough to become unrecoverable in this scenario as well. Homogenous bullets really only excel in magnum cartridges where they can keep speeds high at longer ranges, or in any cartridge at close ranges (inside 200-300 yards). I'm aware a lot of guys here in this forum are using them in magnums at high velocities as well, which is great. They're also a great option for truly dangerous game that have thick hides and require a tough bullet that will penetrate with ease. Yes, there are tons of hunters out there having good luck with these bullets, I will not dispute that at all, but there are many that have had less than ideal experiences as well. I myself have had my own experiences with them and can say first hand that I've not seen any evidence to prove to me that they're anywhere near superior to a traditional well-constructed cup and core bullet that was/is used within its own set of limits. Plus, they typically cost a lot more! I'd only ever continue to use them if I were forced to due to lead-free requirements. That is my own personal opinion though, so please don't read too far into that and think I'm implying anyone that uses them is foolish. I'm not here to cast judgment. When I did use them, I didn't have a single lost animal, but my close examinations of the wounding I saw showed performance that was greater influenced by good shot placement rather than pure bullet performance. I was fortunate enough to place my shots well, but I know I can't always count on that out in the field under harsh conditions.
To elaborate further: Almost all solid copper bullets do not shed weight and thus do not decrease their amount of sectional density as they travel through an animal. With those types of bullets, you typically get too much penetration because they retain all their weight and sectional density. They tend to over penetrate. Contrary to popular belief, that's not actually desirable. You only need that if you take bad shots like infamous Texas heart shots, where you're asking the bullet to pass through the entire animal and guts to get to the vital organs, or hunting specific animals that do indeed need a lot of penetration due to their specific anatomy.
Lead core bullets shed weight as they penetrate and expand. The softer/frangible types, like Hornady ELD-M, Sierra TMK, Bergers of the hybrid ogive design, etc work best when you start out with a high sectional density (heavy for caliber version). Because of that, they penetrate as needed from the start and then begin expanding, transferring massive amounts of hydrostatic and then hydraulic shock, then they shed weight as they experience all the resistance from the expansion and sudden impact, they then effectively lose sectional density as a result of shedding weight, so they continue to penetrate rather than experience shallow penetration, and they carry all the wounding into the vitals. They also continue to expand and mushroom as they're shedding weight, unlike some other bullets that shed petals and such and are left with essentially only the shank/base of the bullet that does minimal damage and just tends to pencils through. There are some better than others in this regard though.
Tougher constructed lead bullets (like your typical thick jacketed and/or bonded and even solid copper varieties) need to actually start out with LESS sectional density for best results because they lose less of it as the penetrate (or don't lose any at all). They don't shed as much weight. Most solids don't lose any weight at all and penetrate way too much.
A lot of people don't understand that though- including many ballisticians working for bullet manufacturers, unfortunately. They can't get past basic physics. They think big and heavy means a bigger hole and it will destroy everything it touches. But it's not that simple. How bullets behave once they impact a body is actually complex. It's complex, but it's fairly standard if you understand it and how the construction and composition of the bullet matters on how it will behave. If you do understand that, you can look at a particular bullet and see how it's constructed and the composition of it, how much sectional density it has, and you'll already have a very good idea of what kind of terminal performance you'll get from it and what kind of limits it'll have.
If you could design a solid copper bullet that can shed weight and lose sectional density as it expands, but doesn't shed so much it ends up only leaving the base to pencil through, you'd have something great. If it could shed significant weight but still mushroom, the results would be really good. The problem though is copper is simply too hard of a metal. It doesn't behave like that. Lead is one of the only metals that is stable and will do that, as well as provide the density required for increased internal and external ballistics as well.
You have a lot of the same issues with large caliber and/or simply tougher constructed lead core bullets. They don't shed enough weight to really perform well at lower impact velocities to perform ideally. And a lot of guys don't understand that going lighter with them will actually produce better terminal performance. One issue there though is the loss of BC when going lighter, so you're losing maximum range by that alone, plus the higher minimum impact velocity such a bullet has. This is why I, and many others, recommend heavy for caliber softer constructed bullets like ELD-Ms, TMKs, and Berger Hybrids. You get plenty of BC, plenty of SD, and extremely good terminal ballistics as a result.
All that said, I fully realize, like I mentioned earlier, that there are indeed places you have to use lead-free bullets. My top recommendation if you're in that situation is the Terminal Shock bullets from Dynamic Research Technologies (DRT). They feature a compressed copper powder core, with a swaged copper jacket. Upon impact, that core begins coming apart and absolutely shreds vital organs. The main downfall to these though is the lack of variety and availability due to them being a relatively small company with not a huge footprint in the market. In fact, last I spoke with the owner, they're struggling to make any of the Terminal Shock varieties due to lack of materials and lack of employees.
My other recommendations would be the T-Rex from Maker, and the Controlled Chaos from Lehigh Defense. These both expand very well due to the extra efforts put into them to weaken the ogives to produce more than average expansion. The LeHighs even shed large petals and do well at reducing sectional density as they penetrate and for their design and composition, do well at producing good wounding. I've still yet to see any results that are significantly better or even as good as a well-constructed cup and core bullet, but if you're limited to lead free, it's better than most.
A lot of other designs have very little done to them to produce adequate expansion and what expansion is produced is typically not in such a way to produce ideal hydraulic shock. Bullets like the Hornady GMX, Nosler E-tip, most Hammer varieties, and even some Barnes have issues with the ogives rolling over the base and not really producing petals that would in turn force tissues and fluids outward nearly as much. I realize I may get chastised for this, but in my experience a lot of the results I've seen with Hammers is them tumbling upon impact. Fort Scott Munitions actually makes solids and has trademarked that term for their bullets. Unfortunately, tumbling can be very unpredictable and inconsistent. I personally prefer a bullet that is predictable, reliable, and consistent. I do know with plenty of impact velocity and good shot placement, Hammers have been proven quite effective, so please don't take me wrong here lol. I've seen a few shots that have evidence of hitting spine too though, and I wouldn't want guys getting the wrong idea or an illusion of good performance from a spine shot. That's really all I want to say on that though. Again, please don't read any further into that. I'm well aware of how many guys have had good results with Hammers specifically here abc I don't want to step on any toes. I was reluctant to even post this due to it.
Below are multiple images showing different examples and a couple examples of lungs with minimal damage due to minimal expansion and hydraulic shock.
These types of bullets were originally made to fill a simple role and purpose. That being a lead-free bullet, but still be able to expand. States such as California have banned lead in hunting bullets for claimed environmental reasons. Thus came about the solid copper bullets, out of necessity. Necessity is the mother of all invention, after all. Since their release into the shooting/hunting community, folks have discovered how they retain most, if not all, of their weight and penetrate very deep (typically exiting). To the hunter that desires this kind of performance, that's big news. They've gained a massive amount of following due to this characteristic alone. Herein lies the problem. Yes, these bullets do indeed penetrate deep, and at pretty much any impact velocity, but that's not always a good thing. At a high impact velocity- well above 2200fps- they will expand very well and impart a great deal of hydraulic (permanent and temporary cavity) and hydrostatic shock. That being said, shot placement is critical with this type of bullet, as is impact velocity. You must hit vitals, and you must impact no less than 2200fps in order for the bullet to expand ADEQUATELY and to inflict enough hydrostatic shock to knock down the animal. Hydrostatic shock is what transfers to the central nervous system (CNS) and will cause it to temporarily shut down and the animal will go into a temporary coma. It's similar to a boxer getting knocked out in a fight. You still need to inflict enough wounding for the animal to bleed out before it can recover. If there's not enough hydrostatic shock, but still enough wounding, the animal may run, but will bleed out and die eventually. This is a more common occurrence, as you either need to hit an autonomic plexus, or have enough energy/speed on impact to reach out and hit the CNS to shut it down, and that's not always achievable.
To elaborate a bit regarding hydrostatic and hydraulic shock, as these terms tend to get misused/misrepresented:
Hydrostatic shock refers to the effect when shock waves travel through flesh to nerve centers, disrupting their ability to emit electrical impulses.
Ironically, the terms hydraulic and hydrostatic shock are actually misused a lot by both hunters and professionals - including ballisticians working for bullet making companies.
The reason why animals drop instantly with chest shots that do not directly strike the CNS, is due to hydrostatic shock transfer to the spine which passes through to the brain. Any high velocity cartridge along with a good bullet properly selected for the particular animal size imparts over half its energy within the first few inches of penetration, creating a shock wave. This electrical shock wave travels outwards via the rib cage until it reaches the spine and then continues through to the central nervous system in the brain (CNS). The result is an immediate loss of consciousness as the body shuts down for diagnostics (temporary coma).
Along with the loss of consciousness, the projectile has also created a large wound channel, draining all of the body's blood within several seconds. The rapid blood loss and trauma cause death to the animal before it has the chance to regain consciousness.
This action creates the illusion that the projectile has knocked its victim to the ground, killing it instantly, but if it doesn't actually inflict sufficient trauma and blood loss, the animal will recover and often times get up and run. So, it's ultimately best to have both hydrostatic AND hydraulic shock.
So continuing on, a homogenous bullet requires a great deal hydraulic shock (large wound cavity), and ideally a great amount of hydrostatic shock as well, in order to kill the best. A typical homogenous bullet does not shed weight and reach out like a softer, frangible, or even a bonded cup and core bullet. If impact velocity is too low, both hydraulic and hydrostatic shock will be minimal and the bullet tends to produce minimal expansion, or none at all. If you miss vitals, you'll likely not kill the animal and it will get away. If you do hit vitals, but it still pencils through them, you'll typically cause a slow and inhumane death. The animal may still travel far enough to become unrecoverable in this scenario as well. Homogenous bullets really only excel in magnum cartridges where they can keep speeds high at longer ranges, or in any cartridge at close ranges (inside 200-300 yards). I'm aware a lot of guys here in this forum are using them in magnums at high velocities as well, which is great. They're also a great option for truly dangerous game that have thick hides and require a tough bullet that will penetrate with ease. Yes, there are tons of hunters out there having good luck with these bullets, I will not dispute that at all, but there are many that have had less than ideal experiences as well. I myself have had my own experiences with them and can say first hand that I've not seen any evidence to prove to me that they're anywhere near superior to a traditional well-constructed cup and core bullet that was/is used within its own set of limits. Plus, they typically cost a lot more! I'd only ever continue to use them if I were forced to due to lead-free requirements. That is my own personal opinion though, so please don't read too far into that and think I'm implying anyone that uses them is foolish. I'm not here to cast judgment. When I did use them, I didn't have a single lost animal, but my close examinations of the wounding I saw showed performance that was greater influenced by good shot placement rather than pure bullet performance. I was fortunate enough to place my shots well, but I know I can't always count on that out in the field under harsh conditions.
To elaborate further: Almost all solid copper bullets do not shed weight and thus do not decrease their amount of sectional density as they travel through an animal. With those types of bullets, you typically get too much penetration because they retain all their weight and sectional density. They tend to over penetrate. Contrary to popular belief, that's not actually desirable. You only need that if you take bad shots like infamous Texas heart shots, where you're asking the bullet to pass through the entire animal and guts to get to the vital organs, or hunting specific animals that do indeed need a lot of penetration due to their specific anatomy.
Lead core bullets shed weight as they penetrate and expand. The softer/frangible types, like Hornady ELD-M, Sierra TMK, Bergers of the hybrid ogive design, etc work best when you start out with a high sectional density (heavy for caliber version). Because of that, they penetrate as needed from the start and then begin expanding, transferring massive amounts of hydrostatic and then hydraulic shock, then they shed weight as they experience all the resistance from the expansion and sudden impact, they then effectively lose sectional density as a result of shedding weight, so they continue to penetrate rather than experience shallow penetration, and they carry all the wounding into the vitals. They also continue to expand and mushroom as they're shedding weight, unlike some other bullets that shed petals and such and are left with essentially only the shank/base of the bullet that does minimal damage and just tends to pencils through. There are some better than others in this regard though.
Tougher constructed lead bullets (like your typical thick jacketed and/or bonded and even solid copper varieties) need to actually start out with LESS sectional density for best results because they lose less of it as the penetrate (or don't lose any at all). They don't shed as much weight. Most solids don't lose any weight at all and penetrate way too much.
A lot of people don't understand that though- including many ballisticians working for bullet manufacturers, unfortunately. They can't get past basic physics. They think big and heavy means a bigger hole and it will destroy everything it touches. But it's not that simple. How bullets behave once they impact a body is actually complex. It's complex, but it's fairly standard if you understand it and how the construction and composition of the bullet matters on how it will behave. If you do understand that, you can look at a particular bullet and see how it's constructed and the composition of it, how much sectional density it has, and you'll already have a very good idea of what kind of terminal performance you'll get from it and what kind of limits it'll have.
If you could design a solid copper bullet that can shed weight and lose sectional density as it expands, but doesn't shed so much it ends up only leaving the base to pencil through, you'd have something great. If it could shed significant weight but still mushroom, the results would be really good. The problem though is copper is simply too hard of a metal. It doesn't behave like that. Lead is one of the only metals that is stable and will do that, as well as provide the density required for increased internal and external ballistics as well.
You have a lot of the same issues with large caliber and/or simply tougher constructed lead core bullets. They don't shed enough weight to really perform well at lower impact velocities to perform ideally. And a lot of guys don't understand that going lighter with them will actually produce better terminal performance. One issue there though is the loss of BC when going lighter, so you're losing maximum range by that alone, plus the higher minimum impact velocity such a bullet has. This is why I, and many others, recommend heavy for caliber softer constructed bullets like ELD-Ms, TMKs, and Berger Hybrids. You get plenty of BC, plenty of SD, and extremely good terminal ballistics as a result.
All that said, I fully realize, like I mentioned earlier, that there are indeed places you have to use lead-free bullets. My top recommendation if you're in that situation is the Terminal Shock bullets from Dynamic Research Technologies (DRT). They feature a compressed copper powder core, with a swaged copper jacket. Upon impact, that core begins coming apart and absolutely shreds vital organs. The main downfall to these though is the lack of variety and availability due to them being a relatively small company with not a huge footprint in the market. In fact, last I spoke with the owner, they're struggling to make any of the Terminal Shock varieties due to lack of materials and lack of employees.
My other recommendations would be the T-Rex from Maker, and the Controlled Chaos from Lehigh Defense. These both expand very well due to the extra efforts put into them to weaken the ogives to produce more than average expansion. The LeHighs even shed large petals and do well at reducing sectional density as they penetrate and for their design and composition, do well at producing good wounding. I've still yet to see any results that are significantly better or even as good as a well-constructed cup and core bullet, but if you're limited to lead free, it's better than most.
A lot of other designs have very little done to them to produce adequate expansion and what expansion is produced is typically not in such a way to produce ideal hydraulic shock. Bullets like the Hornady GMX, Nosler E-tip, most Hammer varieties, and even some Barnes have issues with the ogives rolling over the base and not really producing petals that would in turn force tissues and fluids outward nearly as much. I realize I may get chastised for this, but in my experience a lot of the results I've seen with Hammers is them tumbling upon impact. Fort Scott Munitions actually makes solids and has trademarked that term for their bullets. Unfortunately, tumbling can be very unpredictable and inconsistent. I personally prefer a bullet that is predictable, reliable, and consistent. I do know with plenty of impact velocity and good shot placement, Hammers have been proven quite effective, so please don't take me wrong here lol. I've seen a few shots that have evidence of hitting spine too though, and I wouldn't want guys getting the wrong idea or an illusion of good performance from a spine shot. That's really all I want to say on that though. Again, please don't read any further into that. I'm well aware of how many guys have had good results with Hammers specifically here abc I don't want to step on any toes. I was reluctant to even post this due to it.
Below are multiple images showing different examples and a couple examples of lungs with minimal damage due to minimal expansion and hydraulic shock.