Does "anyone" ever take Sectional Density into consideration!!

[Buttermilk]

I'll interject my 2 cents into this conversation, though I probably should just keep quiet.

In my opinion, SD is only apples to apples when comparing two or more bullets of similar or same construction, shape, etc. Doing it this way allows one to perhaps see which of the bullets might penetrate farther, all other factors being the same or similar.

When comparing SD of bullets that are quite different in design, construction, shape, etc., these other factors or variables of how the bullets is shaped, constructed, etc., will have a greater influence of how a particular bullet performs compared to another bullet than SD of those bullets. Thus, the other factors influence can and may mask the SD's influence, or make less relevant, on bullet performance.

Bottom line, in my opinion, no one single bullet attribute alone can or should be used to determine which bullet is best suited for a particular use. It's my opinion that all of the bullets attributes or characteristics combined should be used collectively to determine proper usage of a bullet.

For some situations, such as long range, a particular attribute, such as BC, might be elevated in importance, compared to all other physical attributes, while at short to moderate ranges, for some applications such as hunting dangerous game, SD might be come real important as well as bullet construction and design criteria.

So, in summary, it's my opinion that all bullet characteristics need to be considered collectively, and not singularly, with some attributes getting priority for certain situations.

 

[cape cove]

I can't see where the SD # can be useful when taking penetration into account. The SD of a Barnes 180 gr TTSX, 30 cal is .271. This is the same SD # for the Berger 180 gr Elite hunter. I guess we all know which bullet will penetrate the deepest.

 

[Buttermilk]

I can't see where the SD # can be useful when taking penetration into account. The SD of a Barnes 180 gr TTSX, 30 cal is .271. This is the same SD # for the Berger 180 gr Elite hunter. I guess we all know which bullet will penetrate the deepest.

This is exactly why you can't take SD alone for selecting bullets. In the example you gave, the 'other' bullet characteristics override the SD influence of the bullet.

 

[RockyMtnMT]

I think the bottom line is that sectional density is irrelevant if you're already using BC to compare bullets. The formula for BC is Mass/(Cross Sectional Diameter * Coefficient of Form). The formula for sectional density is mass/cross sectional area. So you already have a close component of sectional density built into the formula for BC.

Let's look at two bullets from Hornady as an example: https://www.hornady.com/bullets/rifle/#!/

Both are 220 grain, both have the exact same sectional density, .331. Both have proven to be effective on game, yet one has a BC of .65 and the .3. Unless you are using a lever action or need a round nose for some other non-ballistic related reason, why would you ever choose the round nose? @Dog Rocket already showed us the difference in exterior ballistics at 500 yards and @rfurman24 pointed out the difference in wind drift. I do not understand why you would purposely handicap yourself when shooting at a living animal, makes no sense.

I think the answer to your question is bullet performance after impact. In other words the balance is between ballistic performance and terminal performance. It seems like some people are confusing sectional density with retained weight %.

 

[turkn8r1]

I think now it is all making sense to me. Though each thought process prioritizes each factor differently each attribute must be considered to come up with the solution for the person making the decision based on wants, needs or purpose. That being said when the thread was started about sectional density I don't think it was meant as sectional density was the only thing that matters but that it may not be getting enough attention or not being used sometimes to make the decisions. I do see that all factors along with others construction, shape and purpose are all important and for me gives me more input into my decisions which in turn will hopefully help me make better decisions and could possibly make those decisions easier and even better suited for my intended purpose. In my situation and hopefully others will take out some of the hype and get down to the nuts and bolts of it.

 

[Buttermilk]

Even muzzle velocity has to be taken into consideration.

As an example, a 300 Blackout cartridge using a Barnes 110 TAC-TX or a Nosler 125 BT will blow through a deer just fine. Either of those two bullets in a 300 RUM might not do the same, and likely would blow up the bullet on impact with minimal or no penetration.

 

[Alibiiv]

I think now it is all making sense to me. Though each thought process prioritizes each factor differently each attribute must be considered to come up with the solution for the person making the decision based on wants, needs or purpose. That being said when the thread was started about sectional density I don't think it was meant as sectional density was the only thing that matters but that it may not be getting enough attention or not being used sometimes to make the decisions. I do see that all factors along with others construction, shape and purpose are all important and for me gives me more input into my decisions which in turn will hopefully help me make better decisions and could possibly make those decisions easier and even better suited for my intended purpose. In my situation and hopefully others will take out some of the hype and get down to the nuts and bolts of it.

This is exactly the reason for making this thread!! I was not thinking/stating that sectional density was the catch all of ballistics and considerations for a particular bullet. What the thread was about is that I read all about muzzle velocity, muzzle energy and ballistic coefficients, however I do not read too much about sectional density, thus "does anyone ever look at sectional density when considering a particular cartridge/bullet combination" thread was posted. Mostly all the posts are about muzzle velocity compared with ballistic coefficient. I hunt and I am as concerned about ballistic coefficient and equally concerned about how much penetration I am going to get with a particular weight bullet when considering what bullet I would like to hunt with to get the job done.

 

[bigngreen]

It seems there are a lot of guys wanting the simple answer, an equation that they can plug in their data and get an answer to terminal performance. With so many choices these days and so many strong opinions it can be hard to sort out and the reality is you have to make a decision for yourself based on opening up animals you put bullet in.
You can't get the best information for your hunting with clean hands and not getting arm pit deep in animals.
Each bullet construction performs differently and can be put into a representative group. I ran Barnes like it was a religion, you would be dead to me if you didn't run them but then I was having to put them in a possition that was not their strength and the results made me look, switched to Accubonds again I put them in a possition where they weren't their stongest and I moved on.
How heavy for cal Berger type bullets work I found to be ideal for ME and the shots I take, the issues I had with Monos and Bonded bullets were a thing if the past and everytime I pulled the trigger it was just death and I got the terminal performance that allows me to achieve the quick, one shot clean kill I insist on having. If I started having troubles with a Berger I'd switch in a heart beat because it's about delivering the most lethal package I can with precision inside the condition and range I'm taking an animal.

It's a real struggle to even accurately describes what were looking at, was it SD, was it retained weight or momentum, was energy or BC a factor, how all this works with construction and how do they all work together. I think most of use know what we want when we see it and then try to figure out how to translate that into something we can quantify. Not sure it's possible!

 

[Alibiiv]

It seems there are a lot of guys wanting the simple answer, an equation that they can plug in their data and get an answer to terminal performance. With so many choices these days and so many strong opinions it can be hard to sort out and the reality is you have to make a decision for yourself based on opening up animals you put bullet in.
You can't get the best information for your hunting with clean hands and not getting arm pit deep in animals.
Each bullet construction performs differently and can be put into a representative group. I ran Barnes like it was a religion, you would be dead to me if you didn't run them but then I was having to put them in a possition that was not their strength and the results made me look, switched to Accubonds again I put them in a possition where they weren't their stongest and I moved on.
How heavy for cal Berger type bullets work I found to be ideal for ME and the shots I take, the issues I had with Monos and Bonded bullets were a thing if the past and everytime I pulled the trigger it was just death and I got the terminal performance that allows me to achieve the quick, one shot clean kill I insist on having. If I started having troubles with a Berger I'd switch in a heart beat because it's about delivering the most lethal package I can with precision inside the condition and range I'm taking an animal.

It's a real struggle to even accurately describes what were looking at, was it SD, was it retained weight or momentum, was energy or BC a factor, how all this works with construction and how do they all work together. I think most of use know what we want when we see it and then try to figure out how to translate that into something we can quantify. Not sure it's possible!

I totally agree with everything that you have written here in this post, and for me this thread has answered the question for me. I believe that it is not a given because one particular bullet has a high BC. I do believe that even though a high BC is a part of the equation, it is not the entire entity/equation when bullet selection is decided upon. Based upon the numerous responses with this thread (79) it is apparent to me that there are/were a number of hunters/shooters who have had questions about SD equally as well. Most of the shooting that I do are hunting shots, under 100 yards, but....it does not mean that an opportunity to take a longer shot does not exist. I shoot Barnes TSX 225 grain, 35 caliber out of the 35 Whelen. Whatever was hit with the Barnes, the penetration and exit wounds are beyond expectation. Yet if I am shooting at 300 yards, the Barnes bullets just don't shoot well at all. I have two Whelens and the like the Sierra 225 Gamekings SPBT bullets the best for shooting tight groups at 300 yards. Both point-of-impacts are the same with both bullets, however for close shooting I prefer the Barnes 225s to get the job done. And yes before reading this forum, 300 yards was a poke for me! I'm building a .280 Ackley Improved (wildcat), and......I'm sure that there are many who read this forum who will say that the .280 AI is more than adequate to take a bear down, however I (and most outfitters) will tell you that they prefer the Whelen over the .280 any day. For me the .280 AI is a particular tool for a particular job, and....I like using the right tool for the job. When the build is complete and I get to shoot it, I am sure that there will be more threads posted if I cannot find a thread that will answer my particular question. Right now I am researching threads in hopes of finding a good scope for my build, from the various threads that I have read there's a lot of opinions on this topic too. But that's another thread for later.