Questions about the irrelevance of energy (ft-lbs)

[HandgunHTR]

What is the significance (if any) of these two wound channels being very similar in shape/size, but the bottom one being darker, more opaque throughout the wound channel?

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You should think real hard about the answer to the first part of your question. When you come up with the answer it will make Form’s comments make a lot more sense to you.

 

[Skydog]

You should think real hard about the answer to the first part of your question. When you come up with the answer it will make Form’s comments make a lot more sense to you.

As to your repeated assertion that we need to come up with a “standard” number to describe terminal ballistics, you continue to try to have energy be part of the formula when it has already been pretty well established that it is not a reliable metric for how a wound channel is formed or how big a wound channel will be. Second, you are making the assumption that “energy transfer” is linear. It is not.

Finally, the metric for determining if a bullet is likely to perform within its design parameters upon impact already exists. It is impact velocity and it is readily available from pretty much all of the major bullet manufacturers. Your multiple long-winded posts advocating for something new is the equivalent of designing the Cyber Truck to replace the F-150.

Did you mean to respond to someone other than me? I have not made any of those assertions, long winded posts, etc...maybe this was meant for Stinky Coyote?

 

[HandgunHTR]

the finished bullet holds answers we don't look at or measure, in direct relation to distance travelled and work transferred, and put in common usable view/language (based on numbers)

As to your repeated assertion that we need to come up with a “standard” number to describe terminal ballistics, you continue to try to have energy be part of the formula when it has already been pretty well established that it is not a reliable metric for how a wound channel is formed or how big a wound channel will be. Second, you are making the assumption that “energy transfer” is linear. It is not.

Finally, the metric for determining if a bullet is likely to perform within its design parameters upon impact already exists. It is impact velocity and it is readily available from pretty much all of the major bullet manufacturers. Your multiple long-winded posts advocating for something new is the equivalent of designing the Cyber Truck to replace the F-150.

 

[HandgunHTR]

Did you mean to respond to someone other than me? I have not made any of those assertions, long winded posts, etc...maybe this was meant for Stinky Coyote?

I did. I have edited it. Your avatar pics look the same. Sorry.

 

[Skydog]

I did. I have edited it. Your avatar pics look the same. Sorry.

No problem!

 

[HandgunHTR]

here's a question, you got a 6.5 grendel 123 gr eldm on one side of you while sitting in camp, a 308 168 gr eldm on the other side of you, both launching same sd bullets at same velocity, big ole g-bear strolls into camp and starts acting up, what rifle are you picking up and why? any objective information there to support your answer?

Whichever one is too the right of me as that is the one I can shoulder faster, being right-handed and all. Nothing else matters to me in this scenario. I don’t give a rat’s furry bottom about the SD of the bullet, or its diameter, and since the bear is already in camp, both will be well above 1800 fps impact velocity.

If I have time to contemplate, I choose the Grendel as I know I can put more rounds on target, quicker with it than with the 308.

 

[Stinky Coyote]

Here's a question: Have you tried to look anything up on your own about this type of data? Do you know about gelatin testing, FBI protocol on the testing, etc?

Here are some links to get started. They are more long winded than your posts, but contain the information you're seeking.

Clear Gel vs Calibrated Organic Ballistic Gel - Good primer of the importance of calibration.

Basics of the FBI Protocol

Hornady Law Enforcement Ammunition & Test Report Application Guide - This is like a ballistic bible for a lot of Hornady ammo. From pistol to rifle to shotgun.

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Okay, Fbi - Hunting, close enough and hunters should use the fbi stuff while we argue hunting stuff. Relax, still great data there to work with. Now lets dumb it down, or boil it down, same thing.

Bullets get assigned numbers to help us solve inflight ballistics. Fps, bc. Supported by inflight ballistics calculators. On terminal ballistics we get only the starting numbers of the bullet that changes as soon as it impacts, we get SD and Ft/lbs, both of which leaves the rest up for subjective interpretation. Nothing to represent the 'rate of change' to either of those starting numbers, and no calculator support.

6arc 106gr
Impact (Bullet Start) - 2647 fps, 1650 ft/lbs, .256 sd, .243" diam.
Final (Bullet Finish) - Penetration 18", .039 sd, .53" diam., 76.8gr
WTR (Work Transfer Rate) - 91.7 ft/lbs/inch or 5.5%
SDRR (Sectional Density Reduction Rate) - 4.7%

6.5cm 147gr
Impact (Bullet Start) - 2646 fps, 2286 ft/lbs, .301 sd, .264" diam.
Final (Bullet Finish) - Penetration 16", .026 sd, .61" diam., 68.4gr
WTR (Work Transfer Rate) - 142.9 ft/lbs/inch or 6.2%
SDRR (Sectional Density Reduction Rate) - 5.7%

308 168gr Option 1
Impact (Bullet Start) - 2542 fps, 2411 ft/lbs, .253 sd, .308" diam.
Final (Bullet Finish) - Penetration 15.25", .024 sd, .78" diam., 101.4gr
WTR (Work Transfer Rate) - 155.5 ft/lbs/inch or 6.4%
SDRR (Sectional Density Reduction Rate) - 5.9%

308 168gr Option 2
Impact (Bullet Start) - 2718 fps, 2557 ft/lbs, .253 sd, .308" diam.
Final (Bullet Finish) - Penetration 13.25", .022 sd, .9" diam., 125.5gr
WTR (Work Transfer Rate) - 193 ft/lbs/inch or 7.5%
SDRR (Sectional Density Reduction Rate) - 6.9%

Fun right? Similar bullet construction family so the 'rates' are somewhat close to each other, totally different impact velocities (would need to standardize that if making all comparable apples to apples).

Now, who's got a similar data set for mono's? Because then we get to see much bigger differences in 'rates'. Taking it further go down to varmint bullets with itty bitty starting sd's and see much higher 'rates'....go further again the other way to DG solids and you see the rates drop below mono's.

But a guy starts to see patterns of rates vs depth of penetrations in a comparable way.

Will it tell you exactly what the wound will look like? No, its non linear and somewhat front loaded with frangible bullets and some insurance on the tail end to get to certain depth. But as you toughen up the bullets that wound does become less front loaded with smaller front load and lengthens the overall load.

What we lack, for hunting, is the ability to speak in simple numbers and percentages between all our options. I hope that I'm explaining my interpretation of trying to objectify this, in a useful to hunters, way.

Bullet families will land in 'inches of penetration windows we may desire' at velocities we may desire(cartridge choice to drive the fps we're after).

We will start to see patterns of ft/lbs per inch we know drt's game animal classes at most ranges to coincide with the inches of penetration for those game animal classes. From the minimal end of spectrum to higher end of spectrum or insurance levels for personal comfort. In numbers for a change...not emotions or subjective observations, experiences and comments.

We have 13.25" to 18" options listed above, 4 different velocities, and 91.7 ft/lbs/inch to 193 ft/lbs/inch range in this data set.

Now how to get a standard they can all be run? Average between 2500 and 1500 fps impacts perhaps for SDRR/WTR rates? To see them all against each other?

Maybe a future calculator we would be able to choose a bullet and choose the inches of penetration we want and it will spit out the fps it will take to achieve that and the corresponding work per inch? Ie; in long range hunting maybe we want to compare projectiles based on inches and ft/lbs per inch at our extended distances vs relying on the old '1600 or 1800 fps' info? Would we want to fine tune our choices terminally as much as we do inflight and compare wallop better at hunters distances?

See? you still with me? haha

Special thanks to the fbi for putting this data set together, it's a start, still lots of equation left for the hunters variables though. We typically don't need to understand the point blank potential as illustrated with those impact velocities but combined rates averaged over two different common fps impact velocities would tell us that if that bullet driven way too fast the up close shots will be lots shallower with bigger grenade and might ensure we choose enough sd to cover us for that. Ie; if you ran this example with bullets starting at more typical older sd's of around .2 then these examples would fall well short of the 13.25" of the shortest one here for that construction and game intended and be better suited to coyotes or wolves. Then again, you get the varmint stuff with sd's in the .1's and really see how shallow things go at various speeds.

Anyway, I'm trying to put my brain on paper for y'all and come up with a better way to skin this cat for hunters to discuss terminal ballistics with more objective data to work with.

My gift to you, you're facking welcome!

 

[Stinky Coyote]

Whichever one is too the right of me as that is the one I can shoulder faster, being right-handed and all. Nothing else matters to me in this scenario. I don’t give a rat’s furry bottom about the SD of the bullet, or its diameter, and since the bear is already in camp, both will be well above 1800 fps impact velocity.

If I have time to contemplate, I choose the Grendel as I know I can put more rounds on target, quicker with it than with the 308.

lol, I felt that way until ole g-bear strolled into camp right before dark, then I felt a totally different way and rationalized myself up a few more ft/lbs per inch

 

[Stinky Coyote]

As to your repeated assertion that we need to come up with a “standard” number to describe terminal ballistics, you continue to try to have energy be part of the formula when it has already been pretty well established that it is not a reliable metric for how a wound channel is formed or how big a wound channel will be. Second, you are making the assumption that “energy transfer” is linear. It is not.

Finally, the metric for determining if a bullet is likely to perform within its design parameters upon impact already exists. It is impact velocity and it is readily available from pretty much all of the major bullet manufacturers. Your multiple long-winded posts advocating for something new is the equivalent of designing the Cyber Truck to replace the F-150.

standard number(s), supported by calculators (like inflight ballistics), we only get the starting sd and starting workload, from there it's a subjective crapshoot and imagination, or, random non-standard data sets of some of the available bullets giving part of the possible information at a singular impact velocity, agree, it's not linear transfer, but in shades of death, penetration potential being part of it, the work lands within that threshold and we speak in inches...if you'd like take it further...go for it, and maybe once we get the first versions of this going it could be taken further and understand certain bullet families will front load the work in the first 75% of the travel and others spread it out pretty evenly in the 95% of the travel...etc. etc. but we need to start somewhere beyond crawling around in diapers

 

[WTFJohn]

Okay, Fbi - Hunting, close enough and hunters should use the fbi stuff while we argue hunting stuff. Relax, still great data there to work with. Now lets dumb it down, or boil it down, same thing.

Bullets get assigned numbers to help us solve inflight ballistics. Fps, bc. Supported by inflight ballistics calculators. On terminal ballistics we get only the starting numbers of the bullet that changes as soon as it impacts, we get SD and Ft/lbs, both of which leaves the rest up for subjective interpretation. Nothing to represent the 'rate of change' to either of those starting numbers, and no calculator support.

6arc 106gr
Impact (Bullet Start) - 2647 fps, 1650 ft/lbs, .256 sd, .243" diam.
Final (Bullet Finish) - Penetration 18", .039 sd, .53" diam., 76.8gr
WTR (Work Transfer Rate) - 91.7 ft/lbs/inch or 5.5%
SDRR (Sectional Density Reduction Rate) - 4.7%

6.5cm 147gr
Impact (Bullet Start) - 2646 fps, 2286 ft/lbs, .301 sd, .264" diam.
Final (Bullet Finish) - Penetration 16", .026 sd, .61" diam., 68.4gr
WTR (Work Transfer Rate) - 142.9 ft/lbs/inch or 6.2%
SDRR (Sectional Density Reduction Rate) - 5.7%

308 168gr Option 1
Impact (Bullet Start) - 2542 fps, 2411 ft/lbs, .253 sd, .308" diam.
Final (Bullet Finish) - Penetration 15.25", .024 sd, .78" diam., 101.4gr
WTR (Work Transfer Rate) - 155.5 ft/lbs/inch or 6.4%
SDRR (Sectional Density Reduction Rate) - 5.9%

308 168gr Option 2
Impact (Bullet Start) - 2718 fps, 2557 ft/lbs, .253 sd, .308" diam.
Final (Bullet Finish) - Penetration 13.25", .022 sd, .9" diam., 125.5gr
WTR (Work Transfer Rate) - 193 ft/lbs/inch or 7.5%
SDRR (Sectional Density Reduction Rate) - 6.9%

Except the 6mm bullet had the overall best performance, so your essay is, as previously stated by others, subjective conjecture driven by an inability to understand the data at hand. You clearly did not read much (or any) of the links provided which would explain why the FBI protocol is the one to follow based off everything you have posted.

Good luck moving forward, I don't think you're posting in good faith on the topic so I'm exiting.

 

[Stinky Coyote]

Except the 6mm bullet had the overall best performance, so your essay is, as previously stated by others, subjective conjecture driven by an inability to understand the data at hand. You clearly did not read much (or any) of the links provided which would explain why the FBI protocol is the one to follow based off everything you have posted.

Good luck moving forward, I don't think you're posting in good faith on the topic so I'm exiting.

assume what you like, discussions are about working it out, still in good faith, but also still a smartass

so what parameters make that 6mm option the winner in your interpretation? be specific about each one please, because we will all potentially see not just the fbi data set given but even how I interpreted it....differently for choosing a 'winner'....what we're goals intended for this 'winner'?

I haven't even looked at it in terms of choosing a winner, I love eldm performance so they are all looking good to me, gotta layer in some recoil tolerance, some distances I want performance and more. I may wish the insurance of knowing at least 100 grains will be found at the tail end for insurance comfort? I may not be after anything but deer size game for given choice, give me the shorter penetrating higher energy transferring options please. Did you choose the winner based on 18" and lightest recoil?

Did you see Form's Bambi? Does that not look like 240+ ft/lbs per inch to you? Cull goals might be slightly different than eat to the hole goals. But I think we've established energy is relevant. Can the 6mm 108 can replicate that? Think the rear ham of a deer would look the same using the fbi four samples posted? My money is on the 13.25" 308 dropping 193 ft/lbs per inch if trying to replicate Form's cull example and I know the 108 will do some damage, I have my own grendel 123 example on a moose femur at 125 yards that impressed me plenty so shades of dead are all there, how much damage do you want to add is the question. Also, this is pretty similar comparison, all rapid expansion bullets from basically the same family at typical and similar muzzle velocities...they are all going to do similar and when knife comes out might be hard to tell which did which, especially on broadside deer where plenty of the work has likely left the animal aside from maybe the 13.25" 308 example...that could be quite noticeable difference to the other 3 examples. So they are all winners.

what do they look like at 1800 fps impact now? same winner? would be nice to have a calculator to see right? haha

 

[bmart2622]

This thread needs to die like a bull elk shot in the lungs with anything but a Barnes bullet

 

[Stinky Coyote]

anyone notice that 6.5cm 147gr example? weird, highest sd of the group by long shot, not impacting out of the fps range given, only 2nd longest penetration, but man it sure dropped some work!, came out lighter than the little 6mm pill, very interesting, that's prolly most appealing one in there to me if looking at expected drt performance but so is the first 308 option and splitting c-hairs with the 147 option, bit more work over same distance for a bit more recoil, the 2nd 308 option I already know is out of recoil range I would look at

 

[rookieforever33]

This thread needs to die like a bull elk shot in the lungs with anything but a barnes bullet

A bull elk shot with a 14 grain rubber band at 200fps would be dead by now.