GTA
All Springer/NP/PCP Air Gun Discussion General => Hunting Gate => Topic started by: JungleShooter on January 10, 2021, 04:39:35 PM
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💀 Quarry: What kills’em dead – the Mechanics of Killing
This thread is PART (1) of a four-part series (cf. below for links to the other threads).
🔴 What kills is a Permanent HOLE in the quarry – nothing else
We use projectiles (pellets and slugs) to kill quarry. But what exactly kills a shot animal (apart from septicemia)?
We say we want to “dump energy” and getting more “energy transfer” – and we know of course that it’s not the energy in and of itself that destroys and kills – we can fire a bullet into a bucket of water and the water absorbs all of the bullet’s energy – but nothing gets destroyed!So, it’s not more “energy” that we want inside of the animal: It’s more destructive work done by the energy inside of the animal!
• The destructive work of a projectile is slicing and crushing (destroying!) the quarry’s tissue (penetrating trauma). The crushed tissue causes a permanent hole, the permanent wound cavity. And scientifically, medically, what kills is a permanent HOLE in the quarry – nothing else. (cf. sources below*)
• There is also non-destructive work done by some of the energy: The momentary stretching of the neighboring tissue along the permanent HOLE, resulting in a temporary wound cavity. At airgun velocities this temporary wound cavity normally does NOT cause any damage. However, in non-elastic “clay quarry” and “play-dough animals” the temporary wound cavity looks permanent and very impressive (esp. to potential subscribers). But clay and play-dough are non-elastic and thus greatly exaggerate the effects of a projectile – the quarry’s tissue is elastic and the only real damage is the permanent HOLE.
And to at least mention the “hydrostatic shock,” even disputed among high velocity ballisticians: We simply admit that the “hydrostatic shock” is not a factor at the low velocities of our AG.
🔴 For the HOLE to kill – it must be in the right place in the quarry
There are two main ways of how the crushed tissue of the permanent wound cavity leads to death (aside from septicemia/ infections, or starvation due to a destroyed jaw):
(1) The function of body parts immediately necessary for survival is hindered, i.e.:
• Brain and spine (central nervous system CNS) are needed not only for voluntary coordinated use of extremities but also for the involuntary control of essential internal body parts (heart!), i.e., “living”.
• Heart, lungs, and the major arteries/veins are needed to transport oxygen to the brain which is essential for its functioning.
(2) The crushed tissue of various organs and muscle tissue includes arteries/veins that are now open and are bleeding (hemorrhaging). The more blood is lost, the less oxygen arrives at the brain which it needs for its functioning (“living”!). And if the blood is lost rapidly, the quarry can be incapacitated due to the quick decrease in blood pressure.
A HOLE is only deadly if it is in the right place. Therefore, shot placement is first!
🔴 The projectiles that make a Better HOLE in the quarry are –– larger, faster, bulldozer-nose, expanding projectiles
After addressing shot placement(!), we can try to improve the permanent wound cavity as follows:
(1) The wider the diameter of the projectile (pellet or slug) the wider the diameter of the HOLE. And more crushed tissue is better.
➔ Therefore, a larger caliber can be an advantage. Or a projectile that expands upon impact – that’s where the hollow points come in.
(2) The deeper the projectile penetrates the quarry the longer the HOLE. And again, more crushed tissue is better than less.
And:
(3) A HOLE with two blood drains (entrance and exit wound) bleeds better than a hole with only one drain. More blood loss in less time kills quicker. ➔ Therefore, with all other things equal, a higher velocity is better. (Typical AG quarry are so small that too little penetration is rarely a problem.)
(4) The larger the meplat – the flat surface of the projectile – the more tissue will actually be crushed when making the HOLE.
(4a) ➔ Therefore:
• Flat points or wadcutters with their very large meplat and sharp edge crush the most tissue (80-90%+ of the projectile’s diameter).
• Second are unexpanded hollow points, with some having meplats as large as wadcutters, though some others have much smaller meplats (the hollow point cup is part of the meplat).
• Last are domed and pointed projectiles that crush only 65-70% of the tissue [figures adapted from Schaefer, 2014-2018, from PB]. Domed and pointed projectiles have a tendency to push the tissue aside instead of crushing it. They cut through flesh much like a welldriller – with ease the drill goes in deep. Clearly, a bulldozer-nose is better than a welldriller-nose. Domed pellets have a higher BC when passing through air, and have therefore also a higher “tissue BC” (as Bob Sterne [GTA: rsterne] describes this).
(4b) ➔ Additionally, hollow points that expand their overall diameter upon impact will crush more tissue (usually, they also expand their meplat). For example, a .22 cal projectile that expands to .295 increases its impact area by 85%, resulting in 85% more tissue crushed! (in metric measurements: A 5.5mm projectile that expands by only 2mm to 7.5mm causes 85% more crushed tissue.)
Note that for a substantial HP expansion the impact velocity must be fairly high, usually at least 700 to 800fps.
(4c) ➔ Sometimes a hollow point projectile will not expand beyond its original diameter. Nevertheless, often its hollow point cup does expand – thus enlarging the meplat. This results in more tissue being crushed.
In many cases hollow points fly with a much better BC than either a wadcutter or a pellet with a larger caliber (and with the same weight) – but upon impact they expand and crush as much tissue as the wadcutter or as the larger caliber pellet: that is the best of both worlds…!
(5) Some projectiles fragment inside the quarry. The HP pellets with ballistic tip usually shed the tip, some pellets leave their expanded head behind and only base with the skirt continues forward (e.g., RWS Super-H-Point), and some projectiles simply come to pieces at very high impact velocities. Sometimes these fragments could create their own wound cavities and increase tissue damage, though at the low AG velocities this is less likely.
(6) Exception for the above principles of a better HOLE:
For some quarry and certain shots we need to make the HOLE into a tough skull before the projectile can do damage to the brain.
➔ Therefore, to break through hard bone the best projectile will have a high impact velocity to actually break through (= the threshold velocity). It will be made from harder lead (lead with a high antimony content, e.g. H&N pellets). It will be domed or pointed rather than a projectile with a large meplat (the flat area that wadcutters and many hollow point pellets have). And it will have a higher sectional density (i.e., heavier if the diameter [caliber] remains the same, or – if the caliber can be varied, rather thin and long, than thick and short).
🔺 This thread is PART (1) of a four-part series, here in logical order and with links to each:
● PART (1) Quarry: What kills’em dead – the Mechanics of Killing
[The current thread.]
● PART (2) How Much Hollow Point Expansion Does How Much More Damage?
• A larger projectile makes a larger HOLE.
• So, how much larger is the HOLE if I go from .177 cal to .25 cal? (results in Table 1)
• And how much larger is the HOLE if my hollow point projectile expands 1/10 of an inch? Or 1mm? (results in Table 2)
https://www.gatewaytoairguns.org/GTA/index.php?topic=182421 (https://www.gatewaytoairguns.org/GTA/index.php?topic=182421)
● PART (3) Hollow Point Pellets – Comparison of Specs & Performance
The attached HP Pellet Specs & Performance Chart (.22cal) answers some of the following questions:
• Which HP projectiles expand better to make a Better HOLE in the quarry? –– The faster, softer HP projectiles with larger, deeper HP cups, and expansion aids do!
• What HP pellets are out there? And how do they compare (specs!)?
• How far could I shoot a certain HP pellet and still expect expansion (given the power of my gun)?
• Some HP are really long and might not fit into my magazine…: How long are the long ones really?
https://www.gatewaytoairguns.org/GTA/index.php?topic=182425 (https://www.gatewaytoairguns.org/GTA/index.php?topic=182425)
● PART (4) Hollow Points – Testing How Much They Expand and How Far They Penetrate
Every hollow point projectile (pellet or slug) performs differently, in line with its specs and the conditions. Find a collection of Projectile Expansion and Penetration Test results for both HP pellets and slugs.
(4a) HP Pellet Projectile Expansion and Penetration Tests
https://www.gatewaytoairguns.org/GTA/index.php?topic=182427 (https://www.gatewaytoairguns.org/GTA/index.php?topic=182427)
(4b) HP Slug Projectile Expansion and Penetration Tests
https://www.gatewaytoairguns.org/GTA/index.php?topic=175823 (https://www.gatewaytoairguns.org/GTA/index.php?topic=175823)
I hope this will be helpful to some!
Matthias
*Sources:
Matt. (2019). Terminal ballistics: How bullets wound and kill. Retrieved from the Everyday Marksman website, at
https://www.everydaymarksman.co/marksmanship/terminal-ballistics/ (https://www.everydaymarksman.co/marksmanship/terminal-ballistics/)
Fackler, Martin L. (1988). Effects of small arms on the human body. Research Report. Letterman Army Institute of Research, Division of Military Trauma Research. Retrieved from https://web.archive.org/web/20120218212956/http://ammo.ar15.com/project/Fackler_Articles/effects_of_small_arms.pdf (https://web.archive.org/web/20120218212956/http://ammo.ar15.com/project/Fackler_Articles/effects_of_small_arms.pdf)
Arborelius, Ulf P. (1999-2013). Shooting holes in wounding theories: The mechanics of terminal ballistics. Retrieved from http://www.rathcoombe.net/sci-tech/ballistics/wounding.html (http://www.rathcoombe.net/sci-tech/ballistics/wounding.html)
Newgard, Ken. (1992). The physiological effects of handgun bullets: The mechanisms of wounding and incapacitation. Wound Ballistics Review, 1(3): 12-17. https://drive.google.com/drive/folders/0B_PmkwLd1hmbd3pWYVVJeGlGaFE (https://drive.google.com/drive/folders/0B_PmkwLd1hmbd3pWYVVJeGlGaFE)
Hollerman, J. J., Fackler, M. L., Coldwell, D. M., & Ben-Menachem, Y. (1990). Gunshot wounds: 1. Bullets, ballistics, and mechanisms of injury. American Journal of Roentgenology, 155(4), 685-690. https://www.ajronline.org/doi/abs/10.2214/ajr.155.4.2119095 (https://www.ajronline.org/doi/abs/10.2214/ajr.155.4.2119095)
Schaefer, John C. (2014-2018). Terminal ballistics. Retrieved from http://www.frfrogspad.com/terminal.htm (http://www.frfrogspad.com/terminal.htm)
and http://www.frfrogspad.com/terminal2.htm (http://www.frfrogspad.com/terminal2.htm)
Gateway to Airguns. (Ed.). (2018). Hunter’s terminal ballistics. [Thread]. Retrieved from https://www.gatewaytoairguns.org/GTA/index.php?topic=148277 (https://www.gatewaytoairguns.org/GTA/index.php?topic=148277)
● Some of Bob’s excellent articles on airgun terminal ballistics (some are about slugs but the principles are similar for pellets):Sterne, Bob [rsterne]. (2020, Apr. 15). The effect of caliber on airgun pellet performance. HardAir Magazine. Retrieved from
https://hardairmagazine.com/ham-columns/the-effect-of-caliber-on-airgun-pellet-performance/ (https://hardairmagazine.com/ham-columns/the-effect-of-caliber-on-airgun-pellet-performance/)
Sterne, Bob [rsterne]. (2020, Jun. 22). Bob Sterne discusses hollowpoint slug design. HardAir Magazine. Retrieved from https://hardairmagazine.com/ham-columns/bob-sterne-discusses-hollowpoint-slug-design/ (https://hardairmagazine.com/ham-columns/bob-sterne-discusses-hollowpoint-slug-design/)
Sterne, Bob [rsterne]. (2020, Mar. 17). Airgun pellet penetration – the real story. HardAir Magazine. Retrieved from https://hardairmagazine.com/ham-columns/airgun-pellet-penetration-the-real-story/ (https://hardairmagazine.com/ham-columns/airgun-pellet-penetration-the-real-story/)
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What kills is a Permanent HOLE in the quarry – nothing else
Yes and no. For example, small game hunting with bow and arrow is done with blunt tips in order to produce blunt force trauma.
There's no penetration. In fact, some "blunt tips" for small game hunting have wires that stick out the sides in order to prevent the arrow from penetrating.
I know of a story where a deer survived having an arrow lodge itself longitudinally in the deer. That's a 28 or so inch penetration with no lethality! the next hunter who shot the deer the next year or so later found the arrow in the deer. Penetration alone isn't a guarantee of making a kill.
Also, there's been numerous people to have shot a critter with a gun, with complete pass through "in the kill zone" yet no lethality, only to have the wounded critter run off in pain and slowly die from an infection in the wound. How that deer didn't succumb to infection is amazing.
Its complicated. However, blunt force trauma is what people are referring to when they say "dumping energy". You want your projectile to transfer energy to your target in order to increase the chances of making a kill.
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Its complicated.
Yes, Tim, it IS complicated! 😄
🔶 And from comments here and elsewhere, I'm realizing I should have been a little more explicit, like stating that we're talking about:
▪ typical airgun velocities (not supersonic)
▪ typical airguns (not big bores and 300 grain slugs, as they usually have their separate sub-forum/gate)
▪ killing typical airgun quarry (not deer, not humans). LOL! 👍🏼😄
Thanks to the interactions on the forums, it helps me to keep learning. I appreciate the comments! 👍🏼
🔶 I think, in the OP I mention septicemia (wound infection) as not being considered in the disussion as a way of killing quarry:
It works. And it's not considered appropriate hunting etiquette (to say the least!).
🔶Blunt force trauma:
I did some searching for the types of trauma — and I have not found blunt trauma as the cause of gun shot kills — on the contrary, it is often distinguished from the trauma caused by a gun's projectile. [Blunt trauma is discussed for bullet shots to the human skull bones and for body armor.]
🔶 Dumping energy:
We want the energy to do destructive work in our quarry.
To illustrate: Do you like FAST cars? I do. And I can dump a lot of energy into the engine of my car — by pushing the accelerator down and having loads of energy in form of gasoline injected into my cylinders. The engine runs FAST, it's almost redlining. WOW!
But is that what I want...?
I want all that energy to get some useful WORK done, not just spin the engine in neutral! So, when I put the engine in gear, NOW all that energy is actually working and producing something useful (140mph on the German autobahn).
➔ In the same way: A projectile can spent a lot of energy inside a quarry making a large temporary cavity — which in most cases will simply snap back as most tissue is elastic. This is non-destructive work (= redlining in neutral).
The useful work I want the energy of my projectile to do is slice and crush tissue — destructive work. This kind of work will produce the permanent wound cavity (the HOLE) I was talking about (= redlining when in gear on the autobahn). 😄
Well, it's getting dark and my quarry is hiding away in the roost. But hey, today two of them ended up with a permanent cavity and consequently will be missing in the roost. Not a bad day, for me at least. 🤣
Matthias
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Matthias,
Thank you for assembling a large volume of information on an important topic. I am new to the forum so this information is largely new to me. I've hunted with powder burners for decades, however, so I am not new to guns and hunting, just air gun hunting.
I agree with what you are saying but I think you are over emphasizing expansion. Typical airgun quarry is relatively small. If we hit the heart or lungs of a squirrel, for instance, with a 22 caliber pellet, we will stop it from functioning, expansion or no expansion. A deer, on the other hand, is much bigger and a 22 caliber hole in it's heart or lungs will not cause death as quickly and it is even possible the animal will recover. So for the deer we need expansion but I do not think it is critical for most small animals we hunt with airguns.
On the other hand, while I think penetration is very important, more important than expansion, we only need enough penetration to reach something vital but I'd rather have an exit hole too (and it seems you agree). If we have much more than that, we waste energy in our projectile that would be better spent making a larger diameter hole. If I shoot a non expanding bullet from my 30-06, for instance, the penetration in ballistic gel would be measured in feet. I think it would be more than 4. Deer are not that large. So expanding bullets are appropriate. But when I shoot a squirrel with my Prod if I did it in the original tune of less than 13 fpe, it did not go through the squirrel - no exit hole - even with domed pellets. Now that I've tuned it up to 17 fpe I seem to be getting pass through and the squirrels do not run away if I miss the head and hit the body. Small sample but I think I am seeing the benefit of pass through.
So I would say expansion is only helpful if we would otherwise waste significant energy going well through the animal. It would seem to be necessary for prompt killing only with body shots and then possibly only with the smallest .177 caliber pellets. It is not a bad thing but if we were to design projectiles that expand at low velocity then we would not get much penetration and we would just make nasty surface wounds on animals. Not good.
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Jim, 😊
thanks for your detailed comments and your comparison of AG and PB quarry.
🔶I can see how the series seemed to overemphasize expansion.... I mostly wrote it about hollow points... — and their point IS expansion...! 😄
So, yeah, the priority over expansion is good shot placement. Of course.
But once we checked that one off, we could consider expansion....
🔶You're probably right when you say that bigger quarry — with bigger vitals — have to have bigger HOLES to kill them quickly. And therefore, expanding projectiles are more important for PB quarry than they are for AG quarry. 👍🏼
And just like you say, if I understood you correctly, expansion continues to be important for AG quarry if we are talking about body shots (I'm thinking for example, rats half hidden behind a wall).
🔶 I think I was assuming for this discussion on AG hunting that we are talking about airguns with significant power. However, some comments elsewhere mentioned using low powered pistols for hunting (or shots at very long ranges).
➔ And then PENETRATION actually might become an issue!
Just like you mentioned, all we need is get through to and through the vitals. (And it's a bonus if we get an exit hole for more bleeding.)
➔ Something I haven't found any testing on is on the conditions that the feathers of a pigeon will redirect or repell a pellet sufficiently to avoid deep penetration, e.g.: What impact velocity, head shape, caliber, and kinetic energy is necessary for a kill?
Fascinating! 😄
Matthias
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Matthias,
A lot of people will appreciate your information gathered up. I think most airgun hunting that I have seen and done boil down to two things, the first being the most important. Shot placement, and having enough energy.
I hunt mainly squirrels and rabbits. I know their anatomy enough to know where my shot placement should be from pretty much any angle I see them from. I mostly shoot a rifle that has enough accuracy and energy to kill them at 50 yards (My second rifle I reduce the range considerably). In reality, I could feel pretty confident of a kill at sixty, but a lot of things could also go wrong at that distance so most of my kills are limited to forty yards or less.
I shoot with diabolo pellets because in my experience those are the most accurate through my rifle and the least affected by air currents. The damage those pellets have done is almost overkill so I don't see a need for hollow point or anything that would detract from accuracy.
The birds I have shot with the same combination basically turn into a puff of feathers and I also reduce my range to make sure I am hitting the center of the vitals.
I can't really hunt much larger quarry where I live with an airgun and since this is an airgun forum that's what makes sense to me here.
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I would agree that expansion is a better idea when we are talking about the smaller end of airgun targets where penetration is not an issue. Rats, small birds, etc.. It is also seemingly harder to place a pellet in these small targets so more damage should lead to quick kills even with non optimum placement. But as you have documented, expansion occurs only at relatively high velocity, typically 800 fps or above. I got a little expansion in wet phone books, however, with metal mags at under 700 fps. But the same caliber that may most need some expansion, the .177, also may be the most likely to supply the necessary velocity to cause it to occur. But the size of this quarry also means that even a non-expanding projectile makes a hole that is pretty significant relative to the size of the quarry. I haven't done it yet but I've been thinking of calculating the size of the hole versus the surface area of the quarry for several weapons. I think it is another factor that may help explain response of the quarry.
It's a sample of one but I shot a squirrel with my 1377 at about 500 fps using a Gamo redfire. I hit the shoulder and broke that side front leg in several places. But it did not go past this into the body cavity. So the squirrel dies slowly and the 1377 got retired from squirrel hunting. Fpe was only about 5. I am pretty confident that my Prod would have gone through the shoulder and hit vitals with the same shot placement, even with the factory tune of about 13 fpe. From wet paper tests I am sure that the redfire did not expand at the low 1377 velocity. But if I shot a rat with it, I would expect it to kill the rat and probably go through it.
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My 1377 is for chipmunk patrol. It has served that job well since 1986. 10 pumps, 515fps with CPHP 7.9s. I have only shot it and oiled it.
The typical chippy shot for me is ambush at 15 or less feet, very effective. I wouldn’t hesitate on a squirrel at that range, but that’s not it’s job.
Poke a hole in the right place is key, and the Wadcutter has been the best tool for me through the years.
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The HP may or may not detract from the accuracy. 2 weeks ago I shot groups with Barracuda hunter hollow points 10.49 grain vs Barracuda Match and the groups were essentially the same. I've had better groups with the Barracuda 9.57 hunter extreme than with the Barracuda domed. I'm not saying that you'd get the same results, but its possible. I've shot 2 red squirrels with domes, in the head. They were incapacitated but still breathing. I've only had one wadcutter that ever failed on a head shot, where it glanced off the top of the skull at an angle, same thing, incapacitated but still breathing. I think the trick is to have something that expands enough to increase the damage but still have just enough energy to exit. So once again we're back to matching the pellet to the quarry. And Stuckrat, I agree that wadcutters work well (for m6 situation and need for less penetration), I've taken out dozens of squirrels with them, unfortunately they're not accurate in my gun. That's why I'm searching for a HP that will work. I'm glad Matthias has gathered all this information and put it in 1 place.
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Many people have more experience than I do but I will share what I have. I've killed squirrels in my back yard with three different tunes of my Prod. The original ~13fpe tune, my initial retune of about 14 fpe, and my current tune of about 17 fpe. I was using either domed pellets or Crosman hollow points which do not expand at Prod velocity. I was disappointed when a body shot squirrel ran over to the other side of my neighbors yard with the original 13 fpe tune. I had earlier nocked one dead right there (DTH) with a head shot. That started me going to higher tunes. I killed a couple with the 14 fpe tune. I hung one of those by it's tail on my "kill tree" and shot it in the side from 20 yards with H&N FTT pellets (13.66 grain) and H&N Baracudas (21 grain). Both stopped with their head on the other side of the squirrel but the skirt still stuck in the skin. That led to an increased diameter transfer port and the current 17 fpe tune. With the bigger transfer port I can get to almost 20 fpe but shot count is really low. I get at least 20 shots over 700 fps with the current tune.
I have not repeated my squirrel penetration test at my current tune but the two squirrels I've killed with it reacted differently than the 4 killed with the lower power tunes. The first moved his head a little or I missed the head and he got hit in the chest facing me. He moved only a few feet and got on the kill tree pointed down. The next shot hit him in the head but under the eye coming out the chin. That stopped him but he was still breathing so he got one more. The next one rolled into a hole in the trunk at the base of the kill tree so I am not sure exactly where he was hit. He started to go up the tree but came back down and seemed to be looking for a place to die. He was on the tree vertical pointed down. I aimed at his head but the gun was shooting a little left when I checked it later so I think I hit him in the neck.
My tentative conclusions are that while 12 fpe will definitely kill a squirrel you pretty much have to hit it in the head to be able to recover it. If you hit it in the body, the squirrel will die but can move far enough to hide and not be recovered. I think something north of 15 fpe is better so a miss placed shot will still likely anchor the squirrel - do enough damage it doesn't run off. If you have 20 fpe or more, you might want pellet expansion so it makes a bigger hole and therefore does more damage. But will less than 20 fpe, I think a domed pellet is a better idea. That will give you enough penetration to shoot through the squirrel sideways and close to the length of the squirrel length wise. That will also do a lot of damage.
I will also say that mis placed shots are not always bad shooting. The "squirrel hunting channel" has an interesting piece about how quickly squirrels move. They can move their head in less than 1/10th the time it takes us to squeeze the trigger and the pellet get there. When they move, our pellet does not arrive where we aimed. So I think it is only reasonable to try and have enough fpe to kill the squirrel quickly even if the shot is not exactly as planned. I have not shot at a squirrel yet with my new 25 caliber Avenger. I am confident it has enough fpe but I haven't found a pellet it likes so I am not confident on shot placement. That is the first thing we need to work on.
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My tentative conclusions are that while 12 fpe will definitely kill a squirrel you pretty much have to hit it in the head to be able to recover it.
well, thats the key point right there .. ive body shot squirrels ~8 times with a .22lr and theyve run off dragging their guts over the fence .. the prod has plenty for squirrels in accuracy and power for head shots, just pick your shots .. a body shot isnt a good idea on squirrel without a 12gauge ...
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I've shot plenty of squirrels with a .22 AG, most were headshots, But I have taken a body shot or 2. With a Meisterkugeln wadcutter 14 grains, it penetrated all the way through. So I'm kind of baffled as to why a Baracuda 21 grain domed pellet did not penetrate completely.
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I think you will be able to see the heads of a copper plated H&N FTT and a Baracuda protruding from the off side of this dead squirrel after I shot it hanging by it's tail at 20 yards. I got more penetration in wet phone books with the Baracuda but I couldn't tell exactly how much because it went through the whole pile - about 4 inches of wet paper. FTT was at least half an inch less. I don't know, shouldn't have been any large bones where I shot it but the Baracuda might have hit a rib and the FTT did not.
I missed a chance to try the current 17 fpe tune on another dead squirrel but plan to repeat it. I also plan to repeat the wet paper test as soon as I build up enough of a stack of paper. I also want to try my 25 caliber Avenger. I'm sure it will have more penetration, question is how much.
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Yes I see the head sticking out. It's strange that your results and mine have been so different. But when I was using H&N match wadcutters (13.73 gr) and 14 grain Meisterkugeln wadcutters, the H&N would usually not penetrate completely on a headshot and the Meisterkugeln always did, and it was finishing shot where I learned the Meister's would go all the way through. So unexpected things do happen. Wonder if it has anything to do with the hardness of the lead (maybe the RWS are harder). I try to limit my penetration due to the area I am shooting so it's something I've payed a lot of attention to.
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I repeated the penetration on a dead squirrel test today. There is a picture on the hunting page. I shot it with Crosman domed, H&N FTT copper plated, H&N Barracuda and metal mags. I could only find three exit holes so I think one of the H&N pellets did not go through. Maybe it was the FTT and maybe the pellet that did not go through hit a rib. Or maybe they all went through and I just didn't find the exit hole. If it hit a rib and went off at an angle that is very possible. The main thing I wanted to know is if my retune of my Prod resulted in pass through. I was pleased to find that at least most of the time it does. I found the metal mag hanging by the fur on the off side. It was completely through the skin, however. It had expanded a little and the metal tip was missing. The hole in the skin on the off side didn't look much different from the other two, however.
If I was mainly worried about not having pass through, I would test some hades and poly mags and choose between them and the metal mag based upon accuracy. I am not so worried about pass through, there is a couple hundred yards of lake in the direction where I could have pass through. So at the limited velocity of any pass through it will just go in the lake. I am more worried about them running off so I want to be sure of enough penetration so I will probably stick with the Crosman domed.
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Great writeup.
I wanna comment on blunt force trama.
I had a successful summer grouse hunting with 33.99 beasts in a 22 prod before and after valve work.
I had a rainbow trajectory but every grouse I hit went down. (I always go for head on grouse)
Every grouse hit before valve mods would have a bloody head but no penetration.
When I finally shot it out of a chrono I was only shooting 350 FPS!
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When I finally shot it out of a chrono I was only shooting 350 FPS!
Jeremy,
350fps with a 34 grainer shows up in my ballistic calculator as only 9FPE.
That's all the muzzle energy your P-Rod produces? 🤔
Or was 350fps the impact velocity?
Matthias
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When I finally shot it out of a chrono I was only shooting 350 FPS!
Jeremy,
350fps with a 34 grainer shows up in my ballistic calculator as only 9FPE.
That's all the muzzle energy your P-Rod produces? 🤔
Or was 350fps the impact velocity?
Matthias
Yes. That was before any valve mods or hammer adjustment. The only change from stock prod was a mrod barrel at that time.
I managed to eventually get my prod up to 950 but was only getting 4-5 good shots before dropping too low.
I also put a .172 barrel on it and was able to get .24 gr slugs up to 910
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Here's a video of a roughly 14 fpe Prod taking a chipper between 20 and 25 yards. The Daisy hollow point did not pass through and you can see the effect of the impact. I'm sorry the sound is out of sync with the video. The impact can be heard before the pellet hits in the video.
https://youtu.be/sGck2TqPPIs
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K=MV squared. It’s that simple. I love your post Mathias. You have clearly put a lot of thought and research into this. There are so many variables at work here it is hard to isolate the important ones. Pellet design and expansion, weight, caliber, velocity, range, shot placement, and toughness of the target.
I’m working with even lower velocities and energy levels than you are with your PCPs. I hunt mostly squirrels. The guns I hunt with most often make between 13 and 15 fpe. At that power level CNS shots are the rule. I have had poor luck shooting squirrels in the torso with 13-15 fpe guns. The .22 pellets I’m using do not expand at those velocities and they produce negligible shock. I’ve got to hit a vital organ to kill a squirrel quickly.
IMO you can’t have too much power. I applaud getting the job done without a pass through but in my experience most of my instantly lethal shots have been pass throughs.
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Interesting to see my comments from early 2021 in this thread. Since I wrote this I figured out my 25 Avenger likes FX 25.4s, bought a P35 in 25 and determined it likes H&N FTTs, and most recently acquired a P35 in 22 and 177. The Avenger has killed 2 squirrels for me and the P35 in 25 has killed 18. The P35 in 177 has killed 2 so far. I've also killed at least half a dozen more with my original PCP, my Prod.
I've recovered the last 11 squirrels I've shot with the little Prod since tuning it up to 17-18 fpe. About half were body shots.
I've recovered all the 18 squirrels I've shot with my P35 in 25 calibler. 8 were body shots. The pellet failed to exit on only 3 of those squirrels. One was a shoulder to shoulder shot and it dropped right were it was hit. Two were lengthwise shots through the body and those squirrels ran 12-15 feet. All the pellets from those 3 were found under the hide.
My Avenger has killed two, both with body shots. Neither squirrel moved far after the hit but one got a second pellet. The pellets all exited.
I've only had the P35 in 177 about a month but have killed two squirrels with it. One was a head shot and it crumpled up and dropped. The other was hit in the shoulder. It moved a couple feet on the limb it was on and fell. It's legs were flailing as it fell and I think if my dog hadn't been there it would have run. She finished it off. This gun is tuned to about 19 fpe and penetrates further than my Prod in wet magazines.
I don't think my additional experience causes me to regret any of my previous statements. I want more data on 177 performance but I remain a little concerned about the size of the holes if makes for body shots. I also want some data from my P35 in 22. It is tuned to shoot H&N Barracuda Match at about 835 fps. It out penetrates my P35 in 25 so I should get even more pass throughs. I expect to see more running after body shots with the 22 and even more with the 177 but we'll see. An expanding pellet should help the 22 and 17 if I find one they like.
But all my PCPs kill squirrels fine when I put the pellet in the right place. I use brain shots when I feel comfortable I can place it properly. If I am a bit shaky, I switch to the larger "vitals" target (or pass on the shot). I shot the top of the skull off a dove, however, and it needed a followup. Head shots are not an immediate kill unless you hit the brain or spine. I had a shot with the P35 in 25 crush the skull on a 8 ounce squirrel (a small one) once, hoever, despite my shot hitting about at the point of the jaw - ahead of the brain I think. Squirrel dropped immediately. I see the margin from the larger calibers as nice to have for both brain and body shots but most important for body shots.
I'm still not a fan of expanding air gun projectiles for the hunting I do but I might get there on the 177. I will only switch if I find one that is accurate, however. Wider hole is not a good trade for worse shot placement. I might also just stop taking body shots with my 177.
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Wider hole is not a good trade for worse shot placement.
The long and the short of it. ;)
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All I can comment on is my own experience with squirrels.
The combination of .177 Meisterkugeln, 600 fps at the muzzle, within 25 yards, in the vitals, has led to dozens of DRT kills. No escapes, no death dances, just drop on the spot. Occasionally they will take the hit and either freeze or run for a couple of seconds but they don't get away. I always find the pellet stuck in the skin on the opposite side. It might pass through if I nail one in the head. Rib or shoulder bones don't seem to matter.
FTT or AADF in .177 from another gun with all the other parameters kept constant leads to the same results.
I don't know why it works but it does, very well.
I think sometimes we hunters (not calling out anyone in this discussion, more what I have seen on youtube) forget that our quarry are living creatures that feel pain and fear rather than just fur-covered spinner targets. If we brag about anything it should be how close we got to the target rather than how long of a shot we connected on. That, however, is difficult to portray on video.
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Brendan,
Thanks for sharing your much broader experience with a 177. I'm a bit wary because of the vigor that seemed to be in the one I body shot but I am still waiting to get a chance to get some more data. I will use my 177 more on squirrels and will use shots to the vitals when that seems to be the best shot I have. I will need to loose a few before I give up that shot and based upon your experience it may not happen.
Dropping quickly will not be as big an issue when I hunt the game lands in SC this fall. As long as they do not get away it won't matter if they run a bit. But in my backyard I like them to drop very quickly because my lot is only 75 feet wide and I don't want them expiring in my neighbors yards. That environment is more where I worry about the 177. My 25 caliber P35 did a great job of dropping them last year. Only two of 18 ran and they didn't get far.
Jim
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Mathias.
"And to at least mention the “hydrostatic shock,” even disputed among high velocity ballisticians: We simply admit that the “hydrostatic shock” is not a factor at the low velocities of our AG".
Great article Mathias,
I can vouch for the above info ref "Hydrostatic Shock", I got a cull job thru the F/G office in Calif (65) era, removing deer that were destroying a grape vine yard, (every deer taken) was taken care of and given to the local senior citizen chapter, so nothing went to waste etc. I got very good at truck skinning a deer........... ;)
My choice of rifle was a 17-222 Rem, PB, a 15gr bullet @ 4000fps, every critter shot (100+) was shot in the eye, at ranges from 25yds thru 50yds, I am hear to tell you, every deer acted like it was electrocuted, legs instantly locked stiff and collapse on the spot without any movement.
Upon examining the results of the hydrostatic shock, was quite an experience and eye opener, with the end results Hard to believe.
Several of the heads were split open to see the results, NO Bone was hit,
just the eye ball, very fine dust type particles (from the 15gr bullet) were found thru out the eye socket.
The hydrostatic shock turned anything it came in contact with to Jellied liquid, the brain was reduced to a very runny scrambled egg's consistency, blood veins were ruptured etc.
It was very hard to understand that a very lite fast bullet could cause that much damage.
I know, we don't have anything close to that with our air guns,
but it sure would be nice to have.
Find and read the report about the Grand Canyon's feral Burro removal,
using 22-250 and 220 Swift calibers with lite weight bullets at over 4000fps etc.
"Gazop, Lites out".
FIRR, I believe that Outdoor Life magazine posted the article.
Thank you,
Don
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Don,
loved your story — what an amazing destruction!! Cool that you got to see hydrostatic shock first hand in your quarry.
Man, 15 grain bullets for powder burners?!? ??? — In Peru where I shoot access to powder burners is very restricted, so I'm pretty ignorant about PB bullets — I had no idea they made such light projectiles for PB!
Matthias
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At that time there was VERY few bullet makers that made bullets for the 17 cal,
I still have several boxes of Sisk 15gr bullets.
Now a days Hornady makes the 17 VMav plastic tipped bullet that are 17 gr's,
and if you pull out the center plastic tips you end up with a 15grs.
A starling centered with one of those 15Vmax makes a perfect round dark circle of feathers, when shot from my 17 XST Weasel case @3650fps, 16"bbl.
I had better stop before the ax falls on me for talking PB lingo.............Lol ;)
Thanks,
Don
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Don's experience is interesting but not at all pertinent to air guns and not really recommended or typical for PBs. I have no doubt in the hands of an expert and at close range a very high velocity and very light weight bullet PROPERLY PLACED can be deadly. I don't think he said it but I am guessing that they were also trying to drop deer without running, may have been an urban area. In many states even a 22 caliber PB is not legal for deer. The issue is with non-ideal shot placement. Like hitting the shoulder. A rapidly expanding light weight bullet may produce a very nasty surface wound which will cause the deer to suffer, possibly for a long time. For most of us, we want to know we have enough penetration to get to the vitals even if we hit a good sized bone.
The latter point is why I test projectiles in MDF and wet paper before using them on game. I want to know I have enough penetration. I have a good calibration on what is enough for a squirrel and one rabbit data point but have to guess on other game. So I listen to others experience and try to make sure I have some margin. Enough penetration for a very well placed brain shot may easily not be enough for a shoulder shot, however.
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Wasn't sure whare to post this, but this thread came to mind... How funny because this pertains to a 15gr .17cal (.177) projectile ;D
This .177 caliber 15gr slug from Nielsen Specialty Ammo was recovered from Plastilina Clay at 30 yards. The PCP being used sends them out at an average of 1055fps (37fpe), and honestly I wasn't sure I'd recover it. As a loose guide, I figure at 80°F (26.6°C) I get half as much penetration in this clay than through game animals. To my surprise, I only had 3" or so of penetration in the clay, so I figure about 6" of critter penetration (As I said, "a loose guide"). Didn't snap a photo of the clay cavity, but it shows promise of these slugs dumping a lot of energy fairly quickly, and from my pellet testing I feel fairly confident in the results (but could be in for a surprise). Currently going through a dry spell of pests, but can't wait to see how these actually perform on game.
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Hmm shortage of critters, make some with clay :)
https://youtu.be/bOGV1K4MP0o
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Hmm shortage of critters, make some with clay :)
;D ;D :D
As wildly entertaining as that would be, I would like to recover one of those slugs from a game critter (if possible). Funny thing, the primary reason for using the slugs is because they're what's most accurate from that gun...
At subsonic speeds I don't expect too much from small caliber hollow points and even question if larger domed/round nose projectiles are better overall. It seems .30cal has gained momentum in the airgun community and isn't quite considered overkill.
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Conservation of energy and relative mass is often breezed over. 9mm vs 200 lbs man does not compare well to 5.5 mm vs. 5 ounce rat, and a 1.5 ounce sparrow just explodes well beyond a 5.5mm wound channel.
Never underestimate a good old fashioned bludgeoning.
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Conservation of energy and relative mass is often breezed over. 9mm vs 200 lbs man does not compare well to 5.5 mm vs. 5 ounce rat, and a 1.5 ounce sparrow just explodes well beyond a 5.5mm wound channel.
Never underestimate a good old fashioned bludgeoning.
I wrote about this some time ago in the hunting gate. Basically, a 7-grain .177 wadcutter pellet impacting the vitals of a 2-pound tree rat would be similar to a 700-grain mini-anvil hitting ME (just under 200#) there. I don't think I would fare well. I also don't think a 1,430 grain domed projectile would kill me much deader. :P
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I don't know... If I'm reading between the lines here, I'm thinking y'all are giving the nod to get a .45cal airgun... ;) ;D
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Hmm shortage of critters, make some with clay :)
;D ;D :D
As wildly entertaining as that would be, I would like to recover one of those slugs from a game critter (if possible). Funny thing, the primary reason for using the slugs is because they're what's most accurate from that gun...
At subsonic speeds I don't expect too much from small caliber hollow points and even question if larger domed/round nose projectiles are better overall. It seems .30cal has gained momentum in the airgun community and isn't quite considered overkill.
What may or may not be considered overkill is rather situational.
.30 cal hp pellet delivering 120 fpe to a coyote, no, same .30 cal pellet on a dove, probably.
Overkill depends on what's on the receiving end, and your plans for the animal afterwards.
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Hitting the kill zone! This is essential even with powder burners. I don't count on hydraulic shock, but If I can hit a pop top regular @ 60 yrds I'm quite confident to use it somewhat to my advantage as my rifle still carries 90 flbs at that distance. Bullet manufacturers have been trying to develop "the perfect" bullet per caliber for yrs! the best (for bringing down a large animal) is the projectile that transfers energy, but still retains a high % of its original weight. It's not all Scientific IMO. Water is a good indication of the expansion possible! I don't believe there is a perfect media for testing expansion.
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What kills is a Permanent HOLE in the quarry – nothing else
Yes and no. For example, small game hunting with bow and arrow is done with blunt tips in order to produce blunt force trauma.
There's no penetration. In fact, some "blunt tips" for small game hunting have wires that stick out the sides in order to prevent the arrow from penetrating.
I know of a story where a deer survived having an arrow lodge itself longitudinally in the deer. That's a 28 or so inch penetration with no lethality! the next hunter who shot the deer the next year or so later found the arrow in the deer. Penetration alone isn't a guarantee of making a kill.
Also, there's been numerous people to have shot a critter with a gun, with complete pass through "in the kill zone" yet no lethality, only to have the wounded critter run off in pain and slowly die from an infection in the wound. How that deer didn't succumb to infection is amazing.
Its complicated. However, blunt force trauma is what people are referring to when they say "dumping energy". You want your projectile to transfer energy to your target in order to increase the chances of making a kill.
I'll bet it was hit with a field point instead of a broad head which has blades to cut a large wound channel so it would bleed out quickly. The field point probably just punched a hole that was smaller than the arrow and sealed off so no blood loss.