What caused the Rokslide shift to smallest caliber and cartridges?

[TaperPin]

It just dawned on me that back when I hunted with a 14” TC Contender pistola, it would have been really nice to have the know how about fragmenting bullets. Pistol hunters must have their own go-to forums?

 

[WeiserBucks]

It just dawned on me that back when I hunted with a 14” TC Contender pistola, it would have been really nice to have the know how about fragmenting bullets. Pistol hunters must have their own go-to forums?

There's a specialty pistol sub forum over on LRH but it doesn't get much traffic.

 

[Marbles]

You obviously know stuff. I am sincerely interested if you can give me more info or links to studies. It’s not always obvious how to find stuff. My google-fu is not that good.

I am also having trouble finding relevance in a lot of your info, for instance, i don’t deal with shooting through sheet of glass.

I can help where he cannot (concluded by him already not answering my questions) and I reframed from posting this reply last night and this morning to give him time to answer yours.

I have trouble finding results as well, so I'm no help there and was hoping the "professional" could assist. His links are largely irrelevant because they relate to bullets that are not what are being used (SMK, FMJ, green tip, Etc). I am not a profession in this capacity, the below is my understanding, I welcome corrections, particularly if data is presented with it.

Regarding the relevance of gel.

Glass (laminated automotive safety glass specifically) is a great stand in for bone. In the FBI protocol it is set on a compound angle, the gel block is 18 inches behind it, so it also test deflection characteristics to an extent.

Bone blind is not a real concept.

Calibrated 10% organic ballistics gel is a good stand-in for tissue, not perfect, but good.

Sand bags are a good stand in for a stomach full of grass (i.e. you cannot reliably shoot through it with most things shoulder fired), which is why there is no tactical standard for sandbag penetration, even though they are frequently used as barriers in combat.

A bullet that does poorly in gel, will likely do poorly in tissue. I would not select a bullet that only penetrated 10 inches or less on game larger than a small deer. I would prefer a round with 14 inches of penetration.

The larger the permanent cavity (I just have to trust others interpretation of what this is), the more tissue damage one can expect.

 

[BjornF16]

I can help where he cannot (concluded by him already not answering my questions) and I reframed from posting this reply last night and this morning to give him time to answer yours.

I have trouble finding results as well, so I'm no help there and was hoping the "professional" could assist. His links are largely irrelevant because they relate to bullets that are not what are being used (SMK, FMJ, green tip, Etc). I am not a profession in this capacity, the below is my understanding, I welcome corrections, particularly if data is presented with it.

Regarding the relevance of gel.

Glass (laminated automotive safety glass specifically) is a great stand in for bone. In the FBI protocol it is set on a compound angle, the gel block is 18 inches behind it, so it also test deflection characteristics to an extent.

Bone blind is not a real concept.

Calibrated 10% organic ballistics gel is a good stand-in for tissue, not perfect, but good.

Sand bags are a good stand in for a stomach full of grass (i.e. you cannot reliably shoot through it with most things shoulder fired), which is why there is no tactical standard for sandbag penetration, even though they are frequently used as barriers in combat.

A bullet that does poorly in gel, will likely do poorly in tissue. I would not select a bullet that only penetrated 10 inches or less on game larger than a small deer. I would prefer a round with 14 inches of penetration.

The larger the permanent cavity (I just have to trust others interpretation of what this is), the more tissue damage one can expect.

Marbles,

Since he is not answering, maybe you can answer this for him:

Is the ballistic gel and auto glass a better indicator than actual field results to include bone impacts?

The FBI ballistic gel testing protocols were meant to test and predict in the absence of actual field results…but if we have actual field results (on game), shouldn’t that have more weight than lab results?

 

[Marbles]

Marbles,

Since he is not answering, maybe you can answer this for him:

Well, I can answer for myself (and myself only).

Is the ballistic gel and auto glass a better indicator than actual field results to include bone impacts?

No. The caveat being a large enough sample with honest reporting. A perfect gel test cannot overcome poor actual field results. On the other hand, it would take very high quality field data to make me believe that a bullet that failed in gel gives good results in the field. When the two agree, then I'm more inclined to believe the results.

The FBI ballistic gel testing protocols were meant to test and predict in the absence of actual field results…but if we have actual field results (on game), shouldn’t that have more weight than lab results?

Yes, but the caveat about honest reporting remains and there is not a quality control mechanism. So, we must make a decision on if we believe them. Because they line up with gel tests, I am more inclined to believe them and think the data is good. I cannot provide proof of that to someone else however.

Now, the catch is that others cannot introduce adequate evidence to make me question me conclusions about the field results being valid. If the 77 gr TMK failed in gel, though would have a much better beachhead from which to make me doubt.

 

[id_jon]

There have been plenty of gel tests of the 77gr TMK, and the results of those gel tests show you exactly what you would expect to see if you've seen its results on game, and vise verse, so the whole tangent has been a bit odd in my opinion.

 

[DJL2]

@Marbles , @BjornF16 ,

Worth what you paid and maybe a bit more:
Ballistics gel is a comparative medium only without correlation. It is a reasonable approximation of some types of tissue. However, you fellas have hunted enough to know that a homogenous gel is not going to be an equally good stand in for muscle, lung, liver, and heart. That goes double for lungs and the thoracic cavity as a whole because there's a fair amount of empty space (lower than tissue levels of resistance) in there.

One of the challenges with the FBI/LE test protocol is the barrier placement. I haven't seen too many game animals with an exoskeleton, let alone an exoskeleton with standoff. Most of them have the bones on the inside. There's just not getting around the fact that shooting through concealment to engage a target on the far side of a car door, a window, drywall, etc. is a much different scenario. A bullet that comes apart on the intermediate barrier will not (may?) have the mass and integrity remaining when it reaches the target to perform as required. That's before considering the nature of the barriers themselves and whether they are a suitable representation of bone. The engineer in me says that without someone proving to the contrary, steel, safety glass, plywood, and wall board aren't good approximations of anything but the intermediate tactical barriers they are intended to represent.

Related specifically to the Doc GKR study presented, you will note with no small irony that 115 grain OTM bullets represented the best performing 6.8 SPC bullets in the test. That presentation is an endorsement of match bullets in small (or intermediate if you prefer) calibers and highlights the importance of short neck length and fragmentation as wounding mechanisms. Nathan Foster notes that from a wounding perspective, the heavy tipped match bullets in .223 Rem largely obviate the need for its intermediate caliber competitors (my caveat: if you don't need barrier blind performance... and hunters don't).

 

[Marbles]

@Marbles , @BjornF16 ,

Worth what you paid and maybe a bit more:
Ballistics gel is a comparative medium only without correlation. It is a reasonable approximation of some types of tissue. However, you fellas have hunted enough to know that a homogenous gel is not going to be an equally good stand in for muscle, lung, liver, and heart. That goes double for lungs and the thoracic cavity as a whole because there's a fair amount of empty space (lower than tissue levels of resistance) in there.

One of the challenges with the FBI/LE test protocol is the barrier placement. I haven't seen too many game animals with an exoskeleton, let alone an exoskeleton with standoff. Most of them have the bones on the inside. There's just not getting around the fact that shooting through concealment to engage a target on the far side of a car door, a window, drywall, etc. is a much different scenario. A bullet that comes apart on the intermediate barrier will not (may?) have the mass and integrity remaining when it reaches the target to perform as required. That's before considering the nature of the barriers themselves and whether they are a suitable representation of bone. The engineer in me says that without someone proving to the contrary, steel, safety glass, plywood, and wall board aren't good approximations of anything but the intermediate tactical barriers they are intended to represent.

Related specifically to the Doc GKR study presented, you will note with no small irony that 115 grain OTM bullets represented the best performing 6.8 SPC bullets in the test. That presentation is an endorsement of match bullets in small (or intermediate if you prefer) calibers and highlights the importance of short neck length and fragmentation as wounding mechanisms. Nathan Foster notes that from a wounding perspective, the heavy tipped match bullets in .223 Rem largely obviate the need for its intermediate caliber competitors (my caveat: if you don't need barrier blind performance... and hunters don't).

I mostly agree. Concepts get simplified to avoid writing pages, I would say it should be obvious the two do not compare 1:1, however the idea that little can be inferred from the tests because of that strikes me as erroneous.

Ballistics gel (when it is 10% organic gel that is calibrated and handled properly) correlates to how a bullet performs in actual bodies, which is why it is used. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6208714/

I think a bullet that grands on laminated safety glass is more likely to be significantly hampered or stopped by bone. One that can pass through laminated safety glass, hold together, then penetrate gel is likely to penetrate bone and do damage on the other side.

Gel also provides a consistent medium to compare bullets. That comparison alone is helpful.

As a side note, unless significant pathology is present, there is nothing empty about the chest cavity (I'm assuming you know this and just worded poorly, but as some people still believe there is empty space, I wanted to point it out). Lung tissue may provide less resistance than some other tissues, but even the resistance of tissues such as muscle and skin will vary from one individual to another, as will bone density. There is no guarantied result.

There have been plenty of gel tests of the 77gr TMK, and the results of those gel tests show you exactly what you would expect to see if you've seen its results on game, and vise verse, so the whole tangent has been a bit odd in my opinion.

I agree.

Things that do well in one, tend to do well in the other. Which is why dismissing either out of hand is not sound reasoning.

 

[Castle Rock]

Quack, Quack
This is the time to show us the light, give us the real deal

What happened to the assault duck, he seems to have gone missing?

 

[DJL2]

I don’t disagree, but I do caveat with: calibrated, 10% ballistic gelatin (and the FBI protocol) correlates well with human physiology. Our fellow mammals are similar in construction, but they differ in a variety of ways too. I haven’t come across data that would provide me the confidence to describe game species minimum performance akin to the 12” standard in humans.

That doesn’t mean the testing isn’t worthwhile, but it does need to be considered alongside the ever growing body of field data. In a sense, I view gel shots as “as good as it gets” - the best that can be expected. Safety glass standard aside, a bullet that doesn’t perform well/consistently in properly calibrated gelatin isn’t really worthy of consideration.

Perhaps a better way to describe “the box” is that it’s compressible. Substantially less dense on the whole than muscle, with some content based variation. Perhaps a distinction without difference in most cases. The neck length test/demo that Doc GKR has in that PPT is an interesting application/consideration in context, I think.

 

[eamyrick]

I can help where he cannot (concluded by him already not answering my questions) and I reframed from posting this reply last night and this morning to give him time to answer yours.

I have trouble finding results as well, so I'm no help there and was hoping the "professional" could assist. His links are largely irrelevant because they relate to bullets that are not what are being used (SMK, FMJ, green tip, Etc). I am not a profession in this capacity, the below is my understanding, I welcome corrections, particularly if data is presented with it.

Regarding the relevance of gel.

Glass (laminated automotive safety glass specifically) is a great stand in for bone. In the FBI protocol it is set on a compound angle, the gel block is 18 inches behind it, so it also test deflection characteristics to an extent.

Bone blind is not a real concept.

Calibrated 10% organic ballistics gel is a good stand-in for tissue, not perfect, but good.

Sand bags are a good stand in for a stomach full of grass (i.e. you cannot reliably shoot through it with most things shoulder fired), which is why there is no tactical standard for sandbag penetration, even though they are frequently used as barriers in combat.

A bullet that does poorly in gel, will likely do poorly in tissue. I would not select a bullet that only penetrated 10 inches or less on game larger than a small deer. I would prefer a round with 14 inches of penetration.

The larger the permanent cavity (I just have to trust others interpretation of what this is), the more tissue damage one can expect.

This is the way I see the matter. I’m no expert but have been involved with many of these test, attended numerous autopsy’s and a lot more less formal evaluations of bullet performance in tissue. I think Form has thrown out the numbers and some how it gets lost but all things equal if the bullet hits the same spot, with equal speed, the larger, similarly designed projectile performs better. Due to wind and my own personal standards, I’m not shooting in the field beyond where I feel highly confident in a first round hit where I was aiming. In this case, I’ll choose the slightly larger caliber because in my small sample size over my hunting career they have performed. I get lost somewhat on the wind performance of 223 at distance compared to a higher BC, faster bullet, but I need all the help I can get.

Lastly, I know this is the internet and tone gets lost in the sauce, but I think the way this information gets presented turns folks off.

 

[BjornF16]

Ultimately, my point was that ballistics gel is a simulator and actual field results should be compared with the simulator to see where the simulator needs to be "improved".

I'm sure the FBI does their forensics to evaluate modern day incidents to compare expected bullet performance with actual field performance.

I shake my head when the field performance (as evidenced by a decent necropsy) is discounted for gel tests. They both have their place, but field performance Trumps.

 

[Formidilosus]

In regards to properly calibrated organic ballistic gelatin testing:

1). Gel works and does have a strong correlation with most mammals of all sizes- deer/elf/bear/moose. This does not mean 12” penetration in gel means only 12” penetration in all shots in tissue.

2). Barrier performance with regard to the FBI protocol and animals- bare gel is useful for “least” upset likely. The heavy clothing test shows mostly likely standard chest or muscle impacts and is probably the most useful, as well can tend to show bullet clogging refusing upset. Auto glass is by far the most stressful thing a bullet can go through- I.E., if a bullet makes it through the auto glass barrier and still penetrates 12” plus, no bone in an animal will stop it.

3). Penetration depth with regards to varying resistance in actual tissue/animals/bones/etc isn’t nearly the issue that one would think. Properly calibrated 10% ballistic gel is a very good average representation of bullet performance across tissue types. In other words- it works.

 

[Formidilosus]

I shake my head when the field performance (as evidenced by a decent necropsy) is discounted for gel tests. They both have their place, but field performance Trumps.

The issue, is that good wound profiles in gel does translate to good wound profiles in tissue. I.E., 77gr TMK does excellently in gel, and does excellent in live tissue. Where people get lost versus reality is things such as “weight retention” and mistaking “weight retention” with actual wound differences in tissue. It has no real value as you are already measuring penetration depth.

 

[S.Clancy]

So, no one should need their CCI 250 or equivalent primers anymore right? I guess I will take them off your hands if I must....

 

[RockChukkar]

When I was first exploring using smaller cartridges I was told by someone who truly "has been there, done that"

"anyone who doubts the effectiveness of .22 centerfires on game simply hasnt done it yet"

I often wish there was a way to take some of the naysayers out and have them watch me shoot a deer, with them not knowing I used a 22-250, .223, swift so on, and then have them guess what I used. I think they would be in disbelief.

Yep.. P.O. Ackley even said the 220 swift was the greatest killer of game animals in North America. Hydrostatic shock is a thing and I’m a believer. Wish there was a larger selection of lighter 50gr+- projectiles that were sufficient for large animals. But I will say the NBT’s work great on white tails.

 

[Shō[t]gun]

1). Gel works and does have a strong correlation with most mammals of all sizes- deer/elf/bear/moose. This does not mean 12” penetration in gel means only 12” penetration in all shots in tissue.

 

[Dirtbag]

Yep.. P.O. Ackley even said the 220 swift was the greatest killer of game animals in North America. Hydrostatic shock is a thing and I’m a believer. Wish there was a larger selection of lighter 50gr+- projectiles that were sufficient for large animals. But I will say the NBT’s work great on white tails.

I'm excited to try the NBT's even though the Hornady 55 SP and Sierra Matchkings have been great.

 

[Macintosh]

In regards to properly calibrated organic ballistic gelatin testing:

1). Gel works and does have a strong correlation with most mammals of all sizes- deer/elf/bear/moose.

Dang, man, why do you hate Christmas? I'm counting on them elves to be in tip-top shape in less than a month!

 

[Macintosh]

re ballistic gel. I know nothing about it per se, but any "test" mandates controlling variables. If variables are not controlled your "test" is invalid (or certainly a LOT less valid) for comparison purposes, becasue you cant say whether the result was due to performance of the subject, or if it was more determined by an uncontrolled variable, and to what degree. Real life has variables that make it harder to draw conclusions from or use for comparison purposes. But the test has to actually represent (or be correlated to) reality in order to draw conclusions from it. Also, tests in general are often representing reality based on one technology and the mechanisms by which it works--if a new technology comes along that accomplishes the same thing via a different mechanism, there is nothing that says the old test will still be predictive of THAT performance in reality--so while it sounds like ballistics gel is a pretty good representation of "reality", I like the comment above that tests always need to be compared to reality, and any time there is a significant divergance from what the test predicts you DO have to ask yourself if the test is actually capable of predicting reality. in this case it sounds like the reality and the test match pretty closely. So what's to question?