HandgunHTR
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- Jan 27, 2022
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.
Questions about the irrelevance of energy (ft-lbs)
- Thread starter Skydog
- Start date
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.
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
WKR
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- Jan 27, 2022
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
WKR
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- Jan 27, 2022
I did. I have edited it. Your avatar pics look the same. Sorry.
No problem!
HandgunHTR
WKR
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- Jan 27, 2022
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
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- Alberta
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
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- Alberta
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
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- Alberta
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
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
WKR
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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? hahaStinky Coyote
WKR
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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
Lil-Rokslider
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DagOtto
Lil-Rokslider
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- Jun 19, 2024
I think that the reason these threads keep coming up and running on and on is exactly because there is NO standardized metric for testing of the terminal ballistic performance of hunting bullets. Without that, we are left to endlessly argue about .223 vs .338, Match versus Copper, Penetration versus Fragmentation, and of course..... ENERGY.
YES, there is a protocol in place for testing of law enforcement / military in gel. But there are almost NO publically available publications showing how various bullets perform in that testing. (According to Form, the Hornady TAP document wasn't even supposed to be in the public domain.) And I would argue that the LE/M protocol leaves out testing the same bullet at high, medium and low impact velocites which is critical for hunters who need to know at what ranges their bullets are likely to perform.
Frankly, I'm frustrated by some folks who keep saying, "the information is out there, you just need to read more online." Nobody on Rokslide or anywhere else has been able to point me to a single document other than the TAP document showing current hunting bullets tested in the manner discussed. I've asked multiple times. There are a few great publications online showing wax tube studies, but not FBI gel, and generally not with current bullet designs.
What some of us are asking is just how hard could it be to tweak the FBI testing protocol slightly to be hunting focused and perform standardized testing that gets published so that all of us can see how various hunting bullets perform compared to others. I've even taken a swing at writing it myself. No need to test bullets through clothes and auto glass,, but maybe test first in bare gel, and second with a layer of leather covered 1/2" OSB in front of the gel block to simulate hide and scapula. And test each bullet with impact velocites of 1700, 2200, 2700 fps. The old metrics of overall penetratioan, wound size and depth to upset are good enough. But it would be even better if we developed a 3d measurement of the wound cavity which should be easy with modern imaging and computers. Then each bullet could have a rating for size of wound channel and total penetration bracketed with max. and min. performance velocities.
We've already got a standardized metric for comparing the performance of bullets for external ballistics in BC. (thank to Brian Litz!) How come nobody has done this for terminal performance which is arguably the most important aspect of what a bullet does? The reason seems to be that it would be somewhat expensive to run this analysis, and nobody thinks that us hunters care enough to pay for the information. And bullet manufacturers seem to love the endless debate on these issues more than we do. Sells more bullets in the end.
I spoke to a ballistic researcher and offered to help find funding for a testing effort like this. He initially got excited by the prospect but then backed off when another researcher he knows claimed he has plans for a similar study. Form has hinted that he knows of something like this that is in the works.
In the mean time, I bought a BB gun (for calibrating gel,) and just need to retire to find the time to do it myself.
YES, there is a protocol in place for testing of law enforcement / military in gel. But there are almost NO publically available publications showing how various bullets perform in that testing. (According to Form, the Hornady TAP document wasn't even supposed to be in the public domain.) And I would argue that the LE/M protocol leaves out testing the same bullet at high, medium and low impact velocites which is critical for hunters who need to know at what ranges their bullets are likely to perform.
Frankly, I'm frustrated by some folks who keep saying, "the information is out there, you just need to read more online." Nobody on Rokslide or anywhere else has been able to point me to a single document other than the TAP document showing current hunting bullets tested in the manner discussed. I've asked multiple times. There are a few great publications online showing wax tube studies, but not FBI gel, and generally not with current bullet designs.
What some of us are asking is just how hard could it be to tweak the FBI testing protocol slightly to be hunting focused and perform standardized testing that gets published so that all of us can see how various hunting bullets perform compared to others. I've even taken a swing at writing it myself. No need to test bullets through clothes and auto glass,, but maybe test first in bare gel, and second with a layer of leather covered 1/2" OSB in front of the gel block to simulate hide and scapula. And test each bullet with impact velocites of 1700, 2200, 2700 fps. The old metrics of overall penetratioan, wound size and depth to upset are good enough. But it would be even better if we developed a 3d measurement of the wound cavity which should be easy with modern imaging and computers. Then each bullet could have a rating for size of wound channel and total penetration bracketed with max. and min. performance velocities.
We've already got a standardized metric for comparing the performance of bullets for external ballistics in BC. (thank to Brian Litz!) How come nobody has done this for terminal performance which is arguably the most important aspect of what a bullet does? The reason seems to be that it would be somewhat expensive to run this analysis, and nobody thinks that us hunters care enough to pay for the information. And bullet manufacturers seem to love the endless debate on these issues more than we do. Sells more bullets in the end.
I spoke to a ballistic researcher and offered to help find funding for a testing effort like this. He initially got excited by the prospect but then backed off when another researcher he knows claimed he has plans for a similar study. Form has hinted that he knows of something like this that is in the works.
In the mean time, I bought a BB gun (for calibrating gel,) and just need to retire to find the time to do it myself.
Fixed it for you.
But seriously, folks, stop feeding the troll.
I'm getting flashbacks to few years ago, before certain members were banned, where we had to scroll past screeds of garbage. Things were much cleaner for a while, there ...
Stinky Coyote
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I stand with DagOtto! 
It's been painful to watch the discussions over the years and everyone use their own subjective vision and random numbers if lucky from experience to help explain why they like what they like and same for everyone else and guys who have only tried one formula telling you it worked for dad and his dad so it's the best etc. THERE HAS GOT to be a better way. We have the grey matter to figure out bullet swim math from 2" to 48" through a constant medium and standard (useful impact velocities), as it relates to HUNTING! And has to be done with all hunting bullets so it is actually useful information and we can see why varmint choices are what they are and why deer class choices are what they are and so on....right on up to DG in Africa.
Some guys seize up if you challenge the big dogs authority over here and a lot of other guys seize up if you throw too much info at em especially if its mathy info with numbers etc. They always show up in these threads. Rather than bow out and realize they are possibly witnessing the birth of modern terminal ballistics they just seize up and add nothing and try to minimize what's being said because it's just too much for their points to handle lol.
I mean look at the one guy....'how do I ignore these type of threads?'....uh, control of your right index finger would be pretty easy bud. If this sh1t hurts your brain....don't read it. Amazing some of the responses you see when you get really into it, data wise or contrary to the local studs too. Just stop...don't type anything that isn't value add, go to a more comfortable thread. LMFAO
It's been painful to watch the discussions over the years and everyone use their own subjective vision and random numbers if lucky from experience to help explain why they like what they like and same for everyone else and guys who have only tried one formula telling you it worked for dad and his dad so it's the best etc. THERE HAS GOT to be a better way. We have the grey matter to figure out bullet swim math from 2" to 48" through a constant medium and standard (useful impact velocities), as it relates to HUNTING! And has to be done with all hunting bullets so it is actually useful information and we can see why varmint choices are what they are and why deer class choices are what they are and so on....right on up to DG in Africa.
Some guys seize up if you challenge the big dogs authority over here and a lot of other guys seize up if you throw too much info at em especially if its mathy info with numbers etc. They always show up in these threads. Rather than bow out and realize they are possibly witnessing the birth of modern terminal ballistics they just seize up and add nothing and try to minimize what's being said because it's just too much for their points to handle lol.
I mean look at the one guy....'how do I ignore these type of threads?'....uh, control of your right index finger would be pretty easy bud. If this sh1t hurts your brain....don't read it. Amazing some of the responses you see when you get really into it, data wise or contrary to the local studs too. Just stop...don't type anything that isn't value add, go to a more comfortable thread. LMFAO
Stinky Coyote
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If you think I'm trolling on this subject you're wrong. If you seize up for whatever reason, going to the default 'troll' comment is submission. I see your submission and carry on, lots of threads I won't engage in as I'm not at a level to do so. You guys give lip...I give lip too, water off a ducks back for me, better be for you too. Don't write off the message due to the messenger for your discomforts. No reason we can't have fun with the lip along the way. If we're gonna break through the wall of objectifying terminal ballistics for hunting there's gonna be some bloody noses.
And...from what I've seen on the interweb, this is probably the best forum to push the boundaries on this topic.
And...from what I've seen on the interweb, this is probably the best forum to push the boundaries on this topic.
Stinky Coyote
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And now that we've moved on from that, is anyone else simmering on that fbi data set? And my interpretation of it? I know I am, there's questions there! I see some very interesting things. And if I do that means others will also, and if say hornady or another leader in these shooting things gets into it like this they will see things also and develop and test products to improve on the anomalies or weird things seen in the numbers to give us even better products. THIS IS THE GOAL. That's why I am interested in this. I don't care about some hurt feelers or having some fun along the way. Kick the can down the road a bit on this and see how it will benefit ALL OF US.
Like maybe they'd see certain calibers (frontal areas), or even ogive profiles, need certain jacket thickness to give same performance at same impact velocities as the other calibers and ogive profiles? That's something I'm already thinking about from this data set and view points. Anyhow...kick the can down the road. Lots of possibilities would arise to develop even better performing products for hunters and make consistent across the calibers for each family (reduce anomalies) etc.
Ie; the 109 vs 108 gr eldm thread(s)? Why does the 108 seem to have more consistent Killy factor? What needs to happen to the 109 to keep it from the odd penciling? Is it the jacket thickness due to the ogive profile that needs to change? Think of the possibilities where this could go. We learn by trial and error on animals still. We could and should change that.
Like maybe they'd see certain calibers (frontal areas), or even ogive profiles, need certain jacket thickness to give same performance at same impact velocities as the other calibers and ogive profiles? That's something I'm already thinking about from this data set and view points. Anyhow...kick the can down the road. Lots of possibilities would arise to develop even better performing products for hunters and make consistent across the calibers for each family (reduce anomalies) etc.
Ie; the 109 vs 108 gr eldm thread(s)? Why does the 108 seem to have more consistent Killy factor? What needs to happen to the 109 to keep it from the odd penciling? Is it the jacket thickness due to the ogive profile that needs to change? Think of the possibilities where this could go. We learn by trial and error on animals still. We could and should change that.
For the record, I don't think you're a troll. I think you're genuine and good-faith. I think there are moments where you get a little "Terrance Howard on Joe Rogan"-ey with the stuff that feels like "here are the theoretical concepts I've come up with to explain why all the experienced people in this field are wrong and my ideas will completely revolutionize this field of study" (hopefully that reference makes sense).
I think a big part of the challenge I see with what you're trying to do here, is that different projectiles use their energy in different ways.
I've recovered 12 gauge shotgun slugs that looked more or less like a silver dollar. That slug used some energy to deform into a pancake shape, and the rest got absorbed as it moved through like a big parachute. Very little tissue cut by that big smooth hunk of lead. Quite a bit pushed out of the way as it passes by.
At the far other end, a broad head cuts a bunch of tissue and blood vessels with almost no energy transferred to the animal.
A heavily fragmenting match bullet turns into a bunch of little sharp shards of metal, which, like the broadhead cut (but not as cleanly obviously) the tissue that is under tension in the temporary stretch cavity. A mono deforms kind of like (but not to the same extent as) that hunk of lead out of a shotgun and uses a lot of energy pushing tissue out of the way that does not really contribute to permanent tissue damage.
A metric that tries to condense that into some universal energy transfer rate term is going to need so many asterisks next to the number that it's going to be less clear than the actual wound channel dimensions from the specific bullet.
If you were dead set on some kind of numerical standard metric, I think something like cubic inches of permanent wound channel in calibrated organic gel, in the first 16" (or 18 or 20, depending on how much value you want to assign to deep penetration) would be a better angle to take (no pun intended).
But I would still rather see the actual wound channel from the actual bullet.
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