Larger diameter bullets allow more room for error?

[Mach 1]

Every so often this get rehashed and it turns out the same. A. Shot placement is very important and B. Match the cartridge to the animal in which your hunting.

 

[FURMAN]

No. Momentum is what I posted. You are trying to bring bc into the discussion which leads to why I never shoot light for caliber bullets.

 

[FIGJAM]

No. Momentum is what I posted. You are trying to bring bc into the discussion which leads to why I never shoot light for caliber bullets.

Ah, got it.

 

[Mach 1]

The interesting thing about the energy calculation is that it doesn't care what the diameter of the object is - just what it weighs and how fast it is going. I am inclined to believe that energy might be more of a compensating factor for error rather than bullet diameter.

Wouldn't the momentum of a .284 150gr bullet be greater than the momentum of a 150gr 308 bullet? Is sectional density related to momentum and how well a bullets retains its momentum?

Sorry, I am a finance major, not a physics major

You are correct but why shoot a 150 grain bullet in a 30 caliber magnum? My wife took a large cow elk last year with a 308 Winchester loaded with 150 smk s. She weighed about 120 at that time so rifle weight was more important than carrying a heavier larger cal gun. Having said that she said she would never take a 308 Winchester again.

 

[FIGJAM]

Every so often this get rehashed and it turns out the same. A. Shot placement is very important and B. Match the cartridge to the animal in which your hunting.

But how many times do guys say there is no replacement for displacement and larger diameter bullets allow for a larger margin of error.

I am just wondering how true those statements are? The more I read everybodies feedback I am still inclined to believe that energy is more important than bullet diameter. I get momentum too, but that seems to be related to energy in a way, at least they should both come to a similar conclusion - that also doesn't take into consideration bullet diameter.

 

[FIGJAM]

You are correct but why shoot a 150 grain bullet in a 30 caliber magnum? My wife took a large cow elk last year with a 308 Winchester loaded with 150 smk s. She weighed about 120 at that time so rifle weight was more important than carrying a heavier larger cal gun. Having said that she said she would never take a 308 Winchester again.

I was just trying to understand momentum - i get the calculation now.

 

[FIGJAM]

Every so often this get rehashed and it turns out the same. A. Shot placement is very important and B. Match the cartridge to the animal in which your hunting.

But what does B mean and how do you do it? I agree with both A and B, but I have been basing B on the energy produced at the max range I might shoot. So if I think that it takes 1500ft lbs of energy to kill an elk and my max range is 1000 yards, i have always believed that I can take any cartridge that produces those numbers and be successful - I have never cared about bullet diameter.

 

[FIGJAM]

I fully believe your logic is mostly sound however bullet construction(as you said) and momentum play a roll. I will repeat, however, momentum has nothing to do with construction. Momentum is mass x velocity. Energy is mass x velocity squared. See how momentum can still be higher at slower speeds. Penetration, as I already stated, does have to do with bullet construction as well as momentum. If you have tons of energy but the bullet comes apart that momentum will quickly be lost. In the end all of this has to be balanced but generally speaking a heavier bullet will create larger wound channels given the same type bullet construction.

So I am reading this again - wouldn't 2 different calibers with equal energy at a given range also have equal momentum? They would have to right? Essentially energy is momentum squared.

 

[Mach 1]

But what does B mean and how do you do it? I agree with both A and B, but I have been basing B on the energy produced at the max range I might shoot. So if I think that it takes 1500ft lbs of energy to kill an elk and my max range is 1000 yards, i have always believed that I can take any cartridge that produces those numbers and be successful - I have never cared about bullet diameter.

Well that's the catch, I'm honest enough to admit that depending the quality of animal I'm willing to push past my practical yardage limits. Admittedly not the most ethical but honest, having said that I love a high bc 338 caliber round. The less the ever changing wind affects me and I always appreciate the extra foot pounds of energy.

 

[Canhunter35]

I thought there might be some wisdom in leaving specific cartridges out of it to avoid the I shoot it therefore it is the best type of discussion.

I definitely think velocity should be part of the discussion. In my heart I have always always based my cartridge choice on energy at the longest range i might take a shot. There was another thread where i ran the energy from a 200 gr 308 bullet at 2850 FPS was 2200 ft lbs at 500 yards and a 264 140 gr bullet at 3300 fps was also 2200 ft lbs. at 500 yards. I see those numbers and think they are equally good for the job on a deer or an elk given the same bullet, for sake of argument lets just say a nosler accubond.

My logic might be flawed, that is why I asked this question. If a larger diameter bullet creates an exponentially larger wound channel with that 2200 ft lbs of energy, then this margin of error that everybody keeps talking about could be legit. If we are talking the difference in wound channel is only .044 with 2200 fr lbs of energy I am thinking the margin of error is immaterial.

Bullet construction, even individual bullets within a line a bullets plays a huge factor in what you're asking.
But usually the more foreign material you launch into an animal the better, a larger bore bullet has the ability to flake pieces of copper off, causing a large wound while retaining a solid chunk that maintains its momentum. Energy and sd do a poor job a translating a bullets effectiveness vs other bullets. Take a 168eldm, it's impressively violent on deer sized game from a 308. a 178 eldx from a 308, only 10 grains more but it tends to punch through, being effective but underwhelming in its performance vs the lighter bullet because of bullet construction, despite having more energy and higher sectional density

 

[FURMAN]

Energy is NOT momentum squared. Re read the formulas.

 

[BigGrizz]

So I am reading this again - wouldn't 2 different calibers with equal energy at a given range also have equal momentum? They would have to right? Essentially energy is momentum squared.

Not necessarily. If you push a smaller projectile faster it can match the energy level. You need the mass of larger rounds to generate momentum. In relation, high SD bullets in smaller calibers accomplish the goal/desire of having more momentum. However, you'll be giving up the surface area and potential surface area for more energy transfer. Simplified, energy = mass*speed.

Like I said, there is some give and take in that, but if we put the convo in terms of bigger 30s and 338s then smaller calibers are fighting an uphill battle at a certain point.

I hope I got that across well enough. I feel like lately we have been really jumping the shark on the web regarding what can be done with smaller projectiles, and the question of "Do we really need something larger?".

 

[FIGJAM]

Energy is NOT momentum squared. Re read the formulas.

I was just reading about it online - helps to see the formulas written out.

 

[Deputy819]

By your reasoning you maybe just should have took the first shot with your 22 pistol, but of course that dosent make sense from an accuracy stand point nor an energy/wound channel stand point. There is a place for the larger calibers

What "reasoning"? It was merely a story that happened to mirror the statement/opinion of another member. If you're refering to the cartridge I used in that story as larger caliber it's "place" was right there. I didnt execute the shot as cleanly as I wanted and the larger diameter bullet did not make up for that error.