Bullet weights?

[mokin]

You guys did an amazing amount of research into a relatively simple question. I didn't read each post but the amount of knowledge demonstrated here is why I like to come here for answers. Anywho....

To get to the original question, based on my personal experience knocking down poppers, I noticed 124 grain bullets are effective at distances where 115 grain bounce off. When you hear the bullet ring the steal three times and the match official says you hit it, move on without knocking it down rather than popping it once and seeing it fall, that 9 grains makes a big difference.

 

[QED]

When it comes to "marginal" handguns you really don't know when a seemingly slight difference can make all the difference. Yes, even just 8% increase in the mass of a bullet can be significant.

 

[QED]

According to several tests, including Lucky Gunner, the 147 gr. HST performed well w/in spec. (12"-18")

It is also subsonic and noticeably easier to shoot out of a micro pistol, and the 124 gr. and 147 gr. are similar in that platform.

​

GR

From one "DocGKR" who tests in Fackler's gel (although most of the time he doesn't give "calibration" information and his gel is less viscous than standard/590 fps/3.35") -- he managed to get this gel fairly close to standard for a test with 147 grain HST:

velocity = 1037 fps, recovered diameter= 0.64", penetration = 11.9". Anytime 147 gr. HST ( around 1000 fps) expands more than 0.62" average recovered diameter (not particularly infrequent) penetration is about 12" or less - in Fackler's bare gel.

 

[481]

From one "DocGKR" who tests in Fackler's gel (although most of the time he doesn't give "calibration" information and his gel is less viscous than standard/590 fps/3.35") -- he managed to get this gel fairly close to standard for a test with 147 grain HST:

velocity = 1037 fps, recovered diameter= 0.64", penetration = 11.9". Anytime 147 gr. HST ( around 1000 fps) expands more than 0.62" average recovered diameter (not particularly infrequent) penetration is about 12" or less - in Fackler's bare gel.

Gelatin validated by a BB fired into it at 590 fps with a penetration depth of 3.35'' is right in the middle of the range of acceptable penetration 3.35 ± 0.1575", so the gelatin that Roberts' is using is not less viscous than standard.

The MacPherson and Schwartz bullet penetration models provide respective maximum penetration depths of 11.84 and 11.69 inches (which includes adding +2 inches for the JHPs' expansion process) confirming that Roberts' test data is just fine.

 

[QED]

Gelatin validated by a BB fired into it at 590 fps with a penetration depth of 3.35'' is right in the middle of the range of acceptable penetration 3.35 ± 0.1575", so the gelatin that Roberts' is using is not less viscous than standard.

Obviously, as I clearly stated, Roberts got it right in his gel preparation for the particular HST test I referenced.

The MacPherson and Schwartz bullet penetration models provide respective maximum penetration depths of 11.84 and 11.69 inches (which includes adding +2 inches for the JHPs' expansion process) confirming that Roberts' test data is just fine.

Obviously, as clearly stated, since Roberts prepared the gel with correct viscosity that time, his penetration for given expansion of that HST test was also correct.
Although MacPherson, with a masters from M.I.T., and a rocket scientist, knew what he was talking about when discussing terminal ballistics, that's not the case with Schwartz, whose academic background is a b.s. in psychology -- and who apparently believes that sonic velocity and bulk modulus, aside from determining density, are independently relevant in bullet penetration (unless he recently managed to learn otherwise).

 

[Zendude]

Hollow point bullet performance can be very sensitive to velocity. Some hollow points perform badly if the velocity is too high or too low. The weight of the bullet in this situation is intended to achieve the ideal velocity with the standard pressure of the cartridge and a certain range of barrel length.

 

[QED]

Hollow point bullet performance can be very sensitive to velocity. Some hollow points perform badly if the velocity is too high or too low. The weight of the bullet in this situation is intended to achieve the ideal velocity with the standard pressure of the cartridge and a certain range of barrel length.

Federal also offers/offered 147 grain HST in +P at nominal mv ~ 1050.

 

[481]

Obviously, as I clearly stated, Roberts got it right in his gel preparation for the particular HST test I referenced.

Obviously, as clearly stated, since Roberts prepared the gel with correct viscosity that time, his penetration for given expansion of that HST test was also correct.
Although MacPherson, with a masters from M.I.T., and a rocket scientist, knew what he was talking about when discussing terminal ballistics, that's not the case with Schwartz, whose academic background is a b.s. in psychology -- and who apparently believes that sonic velocity and bulk modulus, aside from determining density, are independently relevant in bullet penetration (unless he recently managed to learn otherwise).

My post above, #79, never mentioned anything about sonic velocity and bulk modulus, so I am not sure why the continued heart burn exists. Both MacPherson's and Schwartz's bullet penetration equations are accurate and confirm Roberts' data as being correct. Your disapproval or approval of anyone's qualifications in this regard is nothing more than an appeal to authority; such common logical fallacies prove nothing.

Simply because someone has credentials in one discipline—that you may or may not like—does not render them incapable of competence in another.

 

[QED]

My post above, #79, never mentioned anything about sonic velocity and bulk modulus, so I am not sure why the continued heart burn exists. Both MacPherson's and Schwartz's bullet penetration equations are accurate and confirm Roberts' data as being correct. Your disapproval or approval of anyone's qualifications in this regard is nothing more than an appeal to authority; such common logical fallacies prove nothing.

Roberts data for the referenced test was correct and I stated so -- based on MacPherson's penetration equation with constants experimentally obtained from standard 10% ordnance gel. Schwartz's results are of no interest to me, since he, unlike MacPherson, has only a b.s. in psychology and, hardly surprisingly, a demonstrated lack of understanding of mechanics of bullet penetration (bulk modulus and sonic velocity are not independent variables in penetration equation). Since Schwartz's "Quantitative Ammunition" is your declared favorite "gun book" it seems that you picked up that erroneous notion from your favorite book.

Simply because someone has credentials in one discipline—that you may or may not like—does not render them incapable of competence in another.

It doesn't matter what degree someone has or none at all if what they write is not erroneous.

 

[481]

Roberts data for the referenced test was correct and I stated so -- based on MacPherson's penetration equation with constants experimentally obtained from standard 10% ordnance gel. Schwartz's results are of no interest to me, since he, unlike MacPherson, has only a b.s. in psychology and, hardly surprisingly, a demonstrated lack of understanding of mechanics of bullet penetration (bulk modulus and sonic velocity are not independent variables in penetration equation). Since Schwartz's "Quantitative Ammunition" is your declared favorite "gun book" it seems that you picked up that erroneous notion from your favorite book.

It doesn't matter what degree someone has or none at all if what they write is not erroneous.

Misleading claims—that Schwartz's bullet penetration equation has independent variables for bulk modulus and sonic velocity in its composition when it doesn't—do not make for a very convincing argument. Anyone can look at either MacPherson's and Schwartz's bullet penetration equations and see that neither of their equations have such terms in their composition. Not sure why you feel the need to mislead here, but it seems to be a recurrent theme in many of your posts with other members and topics, too.

 

[QED]

Misleading claims—that Schwartz's equation has independent variables for bulk modulus and sonic velocity in its composition when it doesn't—do not make for a very convincing argument. Anyone can look at either MacPherson's and Schwartz's bullet penetration equations and see that neither of their equations have such terms in their composition. Not sure why you feel the need to mislead here, but it seems to be a recurrent theme in many of your posts with other members and topics, too.

If you insist that you did not get your previously expressed erroneous notion that bulk modulus and sonic velocity are independent variables (apart from being variables in equation for density) in penetration equation, from your "favorite gun book" by Schwarz -- fine. However, I''l take MacPherson's results for penetration and expansion instead of Schwartz's simply because I have confirmed to my satisfaction that MacPherson's model provides accurate results -- generally different from Schwartz's results. In addition, the fact that MacPherson obtained M.S. in mechanical engineering from M.I.T. and worked as a rocket scientist for NASA compared to Schwartz, whose degree is b.s. in psychology, makes MacPherson's work more credible.

So, if MacPherson's work predicts some particular bullet penetration for a given expanded diameter -- it is deemed entirely irrelevant what Schwartz predicts.

 

[481]

If you insist that you did not get your previously expressed erroneous notion that bulk modulus and sonic velocity are independent variables (apart from being variables in equation for density) in penetration equation, from your "favorite gun book" by Schwarz -- fine.

Since I've never stated that bulk modulus and sonic velocity are independent variables in either of the bullet penetration equations, your statement is just another ''straw man'' argument that you've pulled from thin air.

However, I''l take MacPherson's results for penetration and expansion instead of Schwartz's simply because I have confirmed to my satisfaction that MacPherson's model provides accurate results -- generally different from Schwartz's results.

Another inaccurate claim. You'll need to do more than just make misleading pronouncements without basis.

So, if MacPherson's work predicts some particular bullet penetration for a given expanded diameter -- it is deemed entirely irrelevant what Schwartz predicts.

Your history of misleading and inaccurate statements here in this thread—and elsewhere on THR—lends little credence to that which you deem relevant or irrelevant. It is hard to tell if you are arguing for the sake of arguing or if you understand that both of modified Poncelet forms (MacPherson and Schwartz) are equal in their accuracy. Regardless of subject, the existence of one model does not automatically negate by its existence the validity of another. To claim so is nonsense.

I'd love to discuss this objectively with you, but whatever is causing your heart-burn means that is unlikely to occur.

 

[QED]

According to several tests, including Lucky Gunner, the 147 gr. HST performed well w/in spec. (12"-18")

It is also subsonic and noticeably easier to shoot out of a micro pistol, and the 124 gr. and 147 gr. are similar in that platform.

​

GR

I looked at the STB tests and indeed they confirm, as I mentioned previously, that 124 grain HST generally penetrates more than 147 grain HST in bare gel, while, of course, expanding less. As also mentioned previously, 147 grain HST (~ 1000 fps) generally does not penetrate more than about 12" in bare 10% standard ordnance gel if its average expanded diameter exceeds about 0.62". A significant percentage of time, as also shown in a test by "DocGKR", 147 grain HST does expand more than 0.62" and thus does not penetrate more than 12" in 10% standard gel (590 fps/3.35").

 

[Garandimal]

Yes, significantly -- meaning ~ 25% or greater (some tissues 100% or more) retarding force (look at the numbers I posted).



Habit, convenience, difference between necessary and necessary-and-sufficient, weighing factors to take into account that gel is not tissue (mechanically speaking).

Of Course!


The velocity or energy lost in protocols barriers is generally less than energy lost due to greater effective diameter of the bullet penetrating bare gel -- that's why penetration is generally less in bare gel (unless the bullet significantly fragments by some barrier, of course).



No. There is no specific requirement for expansion, only penetration (hence 9mm is acceptable.)



The silvertip in "Miami" went into tissue with no clothing barrier; beside, nowadays JHPs are more robustly expanding so a layer or two of clothing is mostly irrelevant.

​

GR

 

[QED]

​

GR

Yes, I saw his "version" of the Miami shootout: lesson being if your tactics are mostly inadequate, your ammunition better not be -- you might not get a chance to make a second shot that could count and thus end the fight and walk away.

 

[Garandimal]

Yes, I saw his "version" of the Miami shootout: lesson being if your tactics are mostly inadequate, your ammunition better not be -- you might not get a chance to make a second shot that could count and thus end the fight and walk away.

His "version," which sounds pretty well documented, has the bullet going through Three(3) layers of clothing.

What is your story and documentation for "went into tissue with no clothing barrier?"

​

GR

 

[QED]

His "version," which sounds pretty well documented, has the bullet going through Three(3) layers of clothing.

What is your story and documentation for "went into tissue with no clothing barrier?"

​

GR

I was referring to Mr. M.P., who was impacted with the "round that changed the FBI" just above his elbow; it was undoubtedly a fairly mild day in Pinecrest when it all went down -- so he most likely did not wear long-sleeved clothing.

 

[Garandimal]

I was referring to Mr. M.P., who was impacted with the "round that changed the FBI" just above his elbow; it was undoubtedly a fairly mild day in Pinecrest when it all went down -- so he most likely did not wear long-sleeved clothing.

So you are guessing.

​

GR

 

[QED]

So you are guessing.

​

GR

Assuming based on probability; I certainly wasn't there. On April 11s, in then Pinecrest, very southern Florida, typically day time temperatures have been in '70s and '80s. Pictures of people seen at the scene on April 11, 1986, shows them wearing short sleeves, none are seen wearing heavy clothing. For more conclusive evidence that you seem to be interested in, you may want to search for a post-gunfight photo of Mr. M.P. and verify that he did not wear long sleeved clothing.

If Mr. M.P. actually did wear something long-sleeved it wasn't much since it did not much help that 115 grain silvertip penetrate more than 8" into his tissues; it over expanded and under penetrated anyway.

 

[94045]

If you were designing a new firearm would you prefer to consult with a random individual with a Doctorate in Mechanical Engineering or John Moses Browning?

I know plenty of idiots with a formal education and.plenty of creditable individuals without one. A degree simply means you had the opportunity to learn the subject. If I had a dollar for every wrong answer I've received from someone with a degree in a subject I would be a rich man.

 

[94045]

Assuming based on probability; I certainly wasn't there. On April 11s, in then Pinecrest, very southern Florida, typically day time temperatures have been in '70s and '80s. Pictures of people seen at the scene on April 11, 1986, shows them wearing short sleeves, none are seen wearing heavy clothing. For more conclusive evidence that you seem to be interested in, you may want to search for a post-gunfight photo of Mr. M.P. and verify that he did not wear long sleeved clothing.

If Mr. M.P. actually did wear something long-sleeved it wasn't much since it did not much help that 115 grain silvertip penetrate more than 8" into his tissues; it over expanded and under penetrated anyway.

My understanding is the Silvertip performed exactly as designed. It met the requirements the FBI had at the time. It was designed to minimize over penetration and possible collateral damage. Not be capable of penetrating an arm and achieving full penetration in a cross body shot. After the fact they decided penetration was more important than possible collateral damage. My understanding now (Related from a DEA Agent) is that Federal Agents's are told to expect every round to exit.

 

[QED]

My understanding is the Silvertip performed exactly as designed. It met the requirements the FBI had at the time. It was designed to minimize over penetration and possible collateral damage.

It was designed based on flawed notion of what causes handgun incapacitation; thus, the FBI learned the hard way the reality of handgun bullet wounding.

Not be capable of penetrating an arm and achieving full penetration in a cross body shot. After the fact they decided penetration was more important than possible collateral damage. My understanding now (Related from a DEA Agent) is that Federal Agents's are told to expect every round to exit.

Arm does get "in the way" in significant percentage of armed conflicts and that must be realistically taken into account, hence 12" minimum soft-tissue penetration requirement (for effective self-defense). Overpenetration, as well as reliance on Fackler's gel for accurate tissue simulation, is seriously challenged by a number of facts, including that a significant percentage of time (~50%) 9mm FMJ shot in a torso doesn't exit (~30" penetration in Fackler's 10% ordnance gel).

 

[94045]

It was designed based on flawed notion of what causes handgun incapacitation; thus, the FBI learned the hard way the reality of handgun bullet wounding.



Arm does get "in the way" in significant percentage of armed conflicts and that must be realistically taken into account, hence 12" minimum soft-tissue penetration requirement (for effective self-defense). Overpenetration, as well as reliance on Fackler's gel for accurate tissue simulation, is seriously challenged by a number of facts, including that a significant percentage of time (~50%) 9mm FMJ shot in a torso doesn't exit (~30" penetration in Fackler's 10% ordnance gel).

I don't disagree with your assertion. Just stating what was related to me. In reality expecting every shot to exit would seem to be sound doctrine even if it seldom occurred.

 

[QED]

If you were designing a new firearm would you prefer to consult with a random individual with a Doctorate in Mechanical Engineering or John Moses Browning?

I know plenty of idiots with a formal education and.plenty of creditable individuals without one. A degree simply means you had the opportunity to learn the subject. If I had a dollar for every wrong answer I've received from someone with a degree in a subject I would be a rich man.

When it comes to bullet penetration analysis, I definitely have a strong bias toward taking seriously a guy with a M.S. in mechanical engineering from M.I.T. (top engineering university in U.S.) who worked as a rocket scientist -- as opposed to a random guy with a b.s. in psychology who goes around various gun forums peddling his "favorite gun book" and nonsense such as that bulk modulus and sonic velocity are independent relevant factors in bullet penetration -- apart from density.

 

[QED]

I don't disagree with your assertion. Just stating what was related to me. In reality expecting every shot to exit would seem to be sound doctrine even if it seldom occurred.

I agree with Fackler on this: lack of penetration could get you killed.