Larger diameter bullets allow more room for error?

Obviously larger bullet diameter is a beneficial factor all things being equal and that is what this (long) thread has been about. However, ethical killing at varying distances is not keyboard physics and is very complex. The variables the shooter can control such as Velocity, Sectional Density, Diameter, Bullet Constructions, Energy and Velocity all give and take from one another and in my opinion need to be tailored for the best COMPROMISE.

Velocity is very important. Too little and the bullet won't expand. Too much and the bullet can explode mid-flight let alone on contact and not penetrate.

Sectional Density is important for penetration. Too much emphasis on penetration may give up too much on tissue damage.

Bullet construction is extremely important. I do not believe there exists a 1 bullet for all applications so it is important to use a bullet for the range and velocity applicable. I personally think it is important to have a short range high velocity bullet and a long range low velocity bullet for cover all bases.

Ballistic Coefficient is very important for retaining velocity and energy at further distances but at the sacrifice of bullet performance and tissue damage.

Larger diameter bullets impart a higher percentage of their energy better than smaller bullets if all other things are equal - no questions at all about this. This is clear when comparing a 6.5 flat faced cylinder to a 7.62mm flat faced cylindrical projectile in a vacuum. A 7.62 is roughly 17.5% larger diameter than a 6.5mm and has roughly 36% more surface area. This is WILL hit harder and transfer more energy at the same velocity. The question really is, since things are not equal, how unequal do these parameters need to be to be equal in performance?

Removed the vacuum and the 7.62 will have a lower BC for the same weight so its effective range will be shorter. Point the cylinders for higher BC and the energy transfer lowers. Add expanding nose technology and the energy transfer goes up. Etc, etc, etc.

Pick any 2 bullets of the same design and construction with the same BC and the larger diameter will be more destructive. NO debate.

BUT... how fast do we need the 6mm to go to equal the 7mm? How fast does the 7mm need to go to equal the 30 cal to off set the advantage of bullet diameter? How much SD is enough? How much energy for species is enough for different bullet diameters? These are very hard questions to answer without advanced degrees in physics and only relate to the projectile. Other factors include the high/low blood pressure of the animal and it's individual fight/flight toughness that just are not predictable.

For the rest of us non-rocket scientists it is perhaps a good idea to use as much gun as you can shoot well while attempting to pick the best compromise between recoil, energy, appropriate minimum velocity for maximum expansion, appropriate max velocity to avoid bullet separation, high enough SD to exit in the worst case scenario, and the best BC in a bullet type to make sure the bullet reaches the target properly. Then hunt within the capabilities of the rifle system and shooter's skills. I think most of us already know this, so the debate is purely for our entertainment, but for those new to longer ranges this all may be very foreign and information might be helpful.

Newer shooters should look for the best performing bullet in a given caliber as the same design may not perform well across all calibers. Choose a cartridge that will provide as much energy and velocity as recommended at your max distance. And then practice, practice, practice! As so many have said, shot placement is THE MOST IMPORTANT factor, yet shooting practice is the factor least invested in by most hunters.
 
What about this...wouldn't a larger diameter bullet disrupt more tissue than a small one of the same genetic makeup if the impact velocity was the same? Or wouldn't that same larger bullet have more momentum to penetrate and make a larger (deeper) wound channel? I'm not talking about a 150 grain 6mm and 150 grain .308, I mean same form and such.
Just keeping the conversation going.
Yes, you are 100% correct regarding the momentum increase, but this does not factor in that bullets expand and slow down in relation to how much expansion takes place. Momentum doesn't kill just as much as energy doesn't.
Yes, a larger diameter bullet does damage more tissue, but it does not necessarily penetrate deeper due to momentum. A .338" 275gr Semi Spitzer out penetrates a .375" 300gr PP in my bullet boxes every single time, as does a .416" 410gr RN bullet.
I'll explain why here, but bullet LENGTH is KING when it comes to penetration.
In bullet expansion testing, their is a thing called the 'parachute effect'. As expansion gets larger, this parachute effect slows the bullet faster. Also, after testing DG bullets from 338, 375, 416, 425, 458, 505, 510 and 585, the larger the diameter of expanding bullets, the less the total penetration is. This is exactly what the parachute effect does, it slows the bullet faster the bigger it is. Now, this does not apply to solid bullets obviously.
Here is another example of energy meaning very little, most DG cartridges were based around 5,000lbs/ft at the muzzle. This is a great number to use, but there are cartridges like the 338WM that only have 4,000lbs/ft at the muzzle that OUT PENETRATE cartridges like the 375H&H, so lbs/ft doesn't trump every time.

Cheers.
 
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Gotcha, but I'm curious. How much more does the 275 grain .338 bullet penetrate over the 300 grain .375? Do you think it matters that they are not the same make bullet or that the .338 in that weight has a Sectional Density of about 12% more? Do the two have the same impact velocity, or do you think that matters?
No being facetious, just trying to have a conversation with a knowledgeable individual to maybe learn something.
 
I feel everyone has touched major concepts on this but the information is so scrambled no one is making sense of anything. I mean, just to answer the op question, a larger cross section in bullet diameter is going to damage more tissue, because it has a larger cross section. For you guys getting off topic and throw expanding rounds into play, as long as the bullet design works, a fully expanded projectile will leave a bigger hole after the first inch or so because, again, there's a larger cross section.

The issue you run into is that a larger cross section will have more resistance in a medium (tissue) (people) (deer) (grandma) as it passes through all the things it needs too. This can be chalked into the 9mm v .45 acp defensive ammo. But before that, let's get into the other stuff.

So we've discover resistance in larger cross sections, but that doesn't really tell us anything in practicality. That's because we are missing a cartridges efficiency and a bullets weight, and design. I want to put aside the design issues because i am biased with that as most people are. A heavier bullet will have more momentum then a lighter bullet in the same FPS range, often time a much heavier bullet will have more momentum then a faster lighter bullet whereas a lighter super fast bullet will give tissue shock. It has a particular look to it, it's usually the stuff on a deer you cut away.
You hydrostatic shock is compression of organs and blood from energy transfer from USUALLY a expanding bullet. The heavier AND faster the more KE and thus the more hydrostatic shock you will get and the more likely you will shut down the CNS on a first round impact.
No reason to get into SD and BCs. While they help, it's "help" is really only helping maintain a projectiles proficiency during its external travel.

The next consideration is the medium it's self. Those of you that shot deer, humans, elk and lastly wild hogs....did you use a anything less than a .26 cal? I mention this because in thicker muscle and higher density in bone, that momentum really does make a difference. Bullet performance can vary depending on design, but the fact is you'll need to offset to a extremely fast cartridge using a lighter bullet to get out of what you get with a 2700 FPS 230 gr will give you in terms of penetration. This is in example, those numbers are orbitrary, so be calm.

So as for a margin of error, I'll use the example of center broadside shooting a deer. Right of the lungs but left of the guts, and having an immediate drop. Your only shot of achieving this is to create enough hydrostatic shock to disrupt CNS functions to create immediate death. As said before, some thing heavy and fast. However as far as the actual hole created from a larger diameter, the odds increased less than 20% in cutting alone. I mean it would just be the luck of the bullets impact vs which anatomy in makes contact with. The luck could be measured by a lighter bullet caliber in inches subtracted by a larger diameter bullet in inches difference in inches equals your margin of error plus shot placement to anatomy.

None of which can be intelligently or predictably be accounted for based off diameter alone.
 
Gotcha, but I'm curious. How much more does the 275 grain .338 bullet penetrate over the 300 grain .375? Do you think it matters that they are not the same make bullet or that the .338 in that weight has a Sectional Density of about 12% more? Do the two have the same impact velocity, or do you think that matters?
No being facetious, just trying to have a conversation with a knowledgeable individual to maybe learn something.
One simple fact is that the HIGHER the velocity is, the faster the bullet expands and therefore the more risk of fragmentation. A slow heavy bullet will penetrate FURTHER because it is expanding slower.
In my example of the 275gr 338 out penetrating a 300gr 375 pill, is conclusive because the velocity was very similar, 2768fps for the 275gr and 2804fps for the 300gr. Both shot at bullet boxes 110yrds(100mtrs) away. Penetration was as follows, the 275gr bullet penetrated 18 1/2" while the 300gr penetrated 14 1/4".
My bullet boxes are 18" square by 60" long. They have steel rods in the top that are at different spacing apart, and then have wet newspaper at different levels of moisture, softened hide/fur at the front and another box in the middle or front for bones/gel depending on test. This box can be placed in any position in the box as all I have to do is slide the racks forward or aft of where I place the box.
I actually copied Jack Lott's bullet box construction I read in a shooting rag from the early 80's, no photos accompanied the article so I had to work off a description only.
Anyway, the Hot Cor and the Woodleigh only differ in jacket material and nose profile. As I also tested the Sierra GK in 300gr and it also penetrated less than the 275gr Speer.
Interesting fact, bullets in the same weight often penetrate to vastly different depths, and some do not go straight, EVER.

Cheers.
 
If the 26 Nosler can't reach 3300 fps without blowing out primer pockets I am probably losing a little interest in the cartridge.

My wildcat 6.5RUMLN hits 3,419 feet per second with 140 Accubonds from a 28" Lilja barrel. The case is a .300 RUM necked to 6.5mm with the shoulder pushed back to match a .338RUM. That gives it a .100" longer neck.
 
After reading the thread for the 257 Sherminator with the 131 Blackjack bullet it appears we have a new elk king on the horizon. Lazer flat trajectory, cuts through wind like hot knife through butter and lastly 1300 ft/lbs of energy at 1000 yards!!! That thing is kicking some serious ***! Gonna have to build one now! Throw all the 300's and 338's in the back of the safe, you don't need them anymore. Slow stir of the old **** pot.
 
My wildcat 6.5RUMLN hits 3,419 feet per second with 140 Accubonds from a 28" Lilja barrel. The case is a .300 RUM necked to 6.5mm with the shoulder pushed back to match a .338RUM. That gives it a .100" longer neck.
How do you keep those Accubonds from not exploding on an elk's shoulders? It was posted yesterday that they explode on fur and can't penetrate to even reach a lung at 250 yards despite being a bonded bullet.
 
..........Some more-what do we do with the energy that is used in transforming the bullet?

One day I wanted to see how much energy it takes to deform a let tip .308 bullet. I set it on the garage floor with the tip oriented vertically. A very hard smash with a hammer and the bullet hit at least two and maybe three walls fast! before coming to rest. Apparently the hammer didn't hit it squarely because there was the slightest scrape on the lead tip. It sure opened my eyes to the energy of a firearm.
 
How do you keep those Accubonds from not exploding on an elk's shoulders? It was posted yesterday that they explode on fur and can't penetrate to even reach a lung at 250 yards despite being a bonded bullet.

Used it only once. I was doing one for me so I rebarreled my son-in-law's. He was the one to use it on a pronghorn about 175 yards distance. Good hit in the lung/heart area so no need for a follow up.

Mine was a 26" Christiansen carbon wrapped. His is accurate. Mine was not, so I disassembled it and sold the parts.
 
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