Connecticut Custom Airguns
  • Welcome!
  • Hector's Airgun Blog
  • Products and Products Blog
    • One-Off's
    • The "Héctors Special'" scope by Sightron
    • K1050i FT
    • The Hex Louver or "Secret Sunshade"
    • Pellet Path Calculator >
      • Questions, Answers and Comments on P-P Calc
      • Privacy Policy for PP-Calc
    • The Nautilus SideWheel
    • The X-10 TiltMeter
  • Zimmer-Silhouetten
    • Results 2017-2018
    • Results 2016-2017
    • Results 2015-2016
    • Results 2014-2015
    • Results 2013-2014
  • References and Links
  • Contact us
  • Store

Hector's Airgun Blog

Where we discuss, CIVIILY,  anything airgun.

Return Home

The OTHER side of an accurate shot

11/14/2013

11 Comments

 
Following our last post on accuracy, some of the first to respond were the hunters, and quite a few from outside the US; which is fun because it gives me a clear idea of the readership of this humble "Blog".
So, Thank You! it is always nice to feel that the whole mess in the fora (forums) is largely just a few loudmouthed individuals, but that there is real hunger out there for articles to help all of us become better airgunners.
In this installment, we will talk of the OTHER side of the accurate shot. Not the launching side, but the receiving side. So we will be discussing some terminal ballistics and some animal anatomy in detail.

IF THIS BOTHERS YOU; PLEASE DO NOT READ FURTHER!
Having issued the "standard disclaimer" let's get down to business:

Some of us, if not a large majority, started our airgunning life as a need to "dispatch" certain predatory creatures. Depending on the region of the world and the needs/wants of each of us perhaps we had a pigeon problem, or a feral cat problem, or a rat problem, or any number of little birds and mammals that really do not grant the use of powder-burners, or act in an environment where the usage of more powerful tools would create more problems than it solved.
Maybe we started by taking care of the vegetable garden and getting rid of the bunnies that ate all the carrots.
Maybe we decided that some supplemental meat would do well for the family.

There are many valid reasons to hunt, and as we became adults and maybe even started paying to hunt (land rental, or landowner permit, or any such "retribution" (not always monetary) for the right to hunt in a specific area, adds an interesting dimension: Game become valuable.  Suddenly, the landowner realizes that poison is not such a good idea after all . . .

In any event we, as hunters, need to ensure that the way we terminate a life (because that is exactly what we do) is as humane as is possible. Even in the case of pests, we cannot deviate from the hunting ethics that dictates to eliminate any un-needed suffering.

How do we do that?

Firstly, we ensure that we hunt with the right tool. In the airgun world, this means enough caliber and penetration to get the job done in the conditions we encounter (prey size/constitution, distance, geographical environment, etc.). If we are limited by law (as is the case in some countries), then we need to alter the conditions (we stalk closer, or stage a blind, or hunt from elevated stands, or any other method), so that we comply with the conditions that are possible, if the ones that are desirable cannot happen. What I want to emphasize here is that hunting is a LOT more than shooting.

Let's state something that is obvious to the experienced airgun hunter, but that is not so obvious to shooters from other areas/disciplines:

Pellets kill by penetration and destruction of vital tissues.

There is no hydraulic shock associated with a pellet impact. There is no "temporary cavity" associated with the path of the pellet as it travels inside an animal.
The pellet needs to penetrate, touch, and destroy the vital tissues; or we have only inflicted a wound, and that is a grave fault that should be avoided; even foregoing the shot, if we are not sure of our target and of our capabilities to make the shot under the specific conditions of that shot.

It is generally accepted that you need about 3 ft-lbs of impact energy to penetrate skin, then 1 ft-lb per inch of animal to reach the vitals. SOME heavy boned animals will need between 2 and 3 ft-lbs more. If you make the addition, you will note that it takes between 7 and 8 ft-lbs to do the job in most airgun-sized prey.

Expanding pellets may be useful but a good chunk of the impact energy is expended in folding the lead back, so penetration is diminished, and in some case, expansion does not really compensate for the reduction in penetration.

At some later date, we will discuss how to make reasonable research about the terminal ballistics of YOUR system (Pellet/Rifle/Scope/Shooter), starting with the creation of the impact media. But that will be later, for now, let's say we know our gun, we know it is accurate to within ½" of POA all the way out to xx yards, and we know that WE are capable of holding the shots well within that margin of error under any and all circumstances. 

We still need something that we do not normally get anywhere else because animals do not walk around with bright red spots where you should aim at; so: ¿Where do we shoot at?

If you have read old hunting books (we normally remember Corbett's, Hunter's, Bell's, Taylor's and other more modern hunters like Capstick) you will remember them describing in detail the aim and the shots taken at bears and lions and leopards, and all sorts of big game. But where do we shoot a frog?, or a rabbit?, or . . . a rat?

We do have general ideas but, are we really, solidly, informed of WHERE to aim at? and why?

A very good friend and knowledgeable airgunner that read this blog on the other side of the world; and got interested in Field Target, came back to me, after reading a little and looking at targets, saying: "You bunch of nincompoops! You've got ALL the kill zones wrong!" LOL! And yes, he is correct. There is very little information out there, especially for small game and pests.

So let´s start this week with a VERY common animal that because it travels well by boat has been the constant companion of humans ever since they started going across water:
Picture
Yes, the ubiquitous rat (usually, Ratus Norvegicus)! We are familiar with the stance, the profile and the different parts of the body, exactly what is inside and where?
This next figure (mostly diagramatic and not in strict correspondence with the other two pictures in this section) will probably inform us better:

Picture
#1 is the brain, fairly large for the size of the animal and the reason why rats are so smart. To the rear of the brain is the cerebellum and at the base of the cerebellum, what is normally called the medula oblongata.
This is the spot that needs to be solidly hit if you want to hit the "lights-off" switch. 
Because there are still some other nervous parts that are still working after a solid hit there, the animal may twitch or show spasms, but the animal is brain dead.
#22 is the heart and #4 are the lungs. Most hunters will prefer this shot to any other because it is a good deal bigger than the brain shot.

A good, solid hit in this area will usually mean that the animal will expire in less than 10 minutes, but even 10 minutes may be 9 minutes too long. If the animal goes into a hole and expires there, the associated decomposition process will be quite unacceptable in a closed urban environment.
#5 is the diaphragm and ANYTHING to the rear of that is a BAD shot. Yes the animal will surely die, but we have infringed on the ethics of hunting.
Note how the BENT ELBOW of the front legs aligns vertically with the position of the heart, this is a good "marker" for broadside shots when using pellets that will produce a permanent hole of at least 5 mm's (0.20" cal.); do note, however, that the heart is about half way between the upper and lower ends of the animal.
  
For frontal shots, note that a shot aimed at JUST BELOW the jaw will do the job.
For shots from the quarters you will need to think and imagine where the vital organs are and then aim accordingly.
For rear shots, do note that the pellet needs to travel completely through the animal so that it hits the vital organs that need to be destroyed.

Now, rats are the product of millions of years of evolution, and this has dictated that the most delicate organs are the most protected. By bones.

To contemplate shots to the brain and immediate areas, we need to first study a little then about the bones:
Picture
As you can see, the brain cavity is fairly high on the head. The eye is always a good pointer of the height at which the brain lies, but the eye itself is a bad aiming spot because the brain is to the rear of the eye itself, the base of the ears are an incredibly good aiming spot on broadside shots.
Frontal shots should be avoided because the slant of the skull makes it hard to get a proper aim point: you will hear many hunters claim that the pellet glanced off the skull in some cases, but this is mostly the perception, in a vast majority of cases what happens is that the slant of the skull creates great difficulties for proper aiming.

When baiting rats (peanut butter & jelly in bread is particularly effective, as is dog food), you will be afforded many shots from the rear, and depending where and how you place and anchor your bait, perhaps some shots at a rat that is reaching upwards. In this case, the brain shot is a very good one to take, as you can aim to the center of the head/neck region and you will be close enough.
Some big-game hunters might be tempted to aim to the hip in the hopes of "anchoring" the prey to be finished off immediately after. One word on that: NO
Small game is much more resilient and feisty than big-game, and most of them can get away real fast on two front legs alone.

Next week we will look in depth (literally), at the Pigeon. Stay tuned.

Meanwhile, move quietly, aim well and shoot straight!







Héctor Medina
11 Comments
JED
11/14/2013 16:44:41

nice, thank u. That little spot is what drives me to get my 30 to shoot small clovers at 20yards. Even large dime size groups at that range bugs me. Just about where i want to be once they send me my skirt sizer from aa.

Reply
Hector Medina link
11/15/2013 03:32:02

Accuracy is a commodity we can never have too much of! LOL!

It is a normal rule of thumb that big bores are not as accurate as medium and small bores, it has to do with harmonic vibrations in the barrel during the pellet's travel along the bore and its exit.

I do not know (you do not tell me) if you are measuring O-O or C-C the groups you relate, but at 20 yards, most of my airguns will punch a single hole, slightly larger than the pellet itself.

Hunting little critters gets iffy beyond the 50 yards line. For me and my 12 ft-lbs spring guns.

;-)

Thanks for reading!




Héctor Medina

Reply
A.O. Martinez
11/18/2013 08:00:43

Bigger-Bore ... "you can make a less accurate hit and still assure a clean kill."

"It is a normal rule of thumb that big bores are not as accurate as medium and small bores,
it has to do with harmonic vibrations in the barrel during the pellet's travel along the bore and its exit."

But, a bigger-bore may provide a buffer for some kill-zone allowance.

So, what airguns do you recommend now, Dr. Beeman (http://www.beemans.net/field%20use.htm)
"Tom Holzel, who may well be the world's leading expert on hunting with airguns, is a very strong supporter of .25 caliber.
Tremendous experience in the field, especially crow hunting, has shown him that the the size of the kill zone increases
significantly with caliber, meaning you can make a less accurate hit and still assure a clean kill.
Practically, this means you can shoot at greater range with the larger calibers.
However, you need an airgun delivering at least 20 ft. lbs. of muzzle energy to really take advantage of the .25 caliber pellet."

Reply
A.O. Martinez
11/18/2013 07:08:05

Target Area, Pellet Energy, Velocity and Range (http://rimfirecentral.com/forums/sho...1&postcount=17)
Quote:
Rat Kill Zone ... 1-inch
POI - Energy/Velocity for Rat ... 5-fpe .177-515fps, 5mm-435fps, .22-380fps, .25-285fps
__________________

Reply
A.O. Martinez
11/18/2013 07:10:55

Link to Target Area, Pellet Energy, Velocity and Range
http://rimfirecentral.com/forums/showpost.php?p=2703741&postcount=17

Reply
A.O. Martinez
11/18/2013 10:42:08


Because of the relatively low-velocities being developed by conventional pellet guns the resultant wounds
can be more likened to the trauma induced by low-to-mid velocity handgun bullets.
Moreover, as Héctor, stated hydrostatic shock (shockwaves) and tissue cavitation are not associated
with the wound channel of an airgun pellet.

GUNSHOT WOUNDS: A SUMMARY (http://www.southampton.ac.uk/~jb3/bullet/gsw.html)
"Principally, there are three mechanisms of tissue damage due to bullets: laceration and crushing, shock waves,
and cavitation (Adams, 1982; Hopkinson and Marshall, 1967; Ordog et al., 1984).
Laceration and crushing are generated by the projectile displacing the tissues in its track and are recognized
as the primary wounding mechanism produced by handguns (Fackler, 1986; Hopkinson and Marshall, 1967).

The degree and amount of laceration and crushing are dependent upon missile velocity, shape, angle of impact, yaw,
and tumbling (Adams, 1982; Ordog et al., 1984). Fackler (1986), however, adds that the shape and construction
of a bullet are not significant factors at such low-velocities as observed in handguns.

Shock waves, the second mechanism often cited as significant in wounding ...
are generated
by high velocity missiles generally exceeding 2,500 feet per second (Hopkinson and Marshall, 1967; Ordog et al., 1984),
and thus not a major factor in most handgun wounds.

Most researchers agree that the wounding effect of the cavitation phenomenon is only significant
in velocities surpassing 1,000 feet per second (Amato et al., 1974; DeMuth, 1966)."

Reply
HECTOR J MEDINA GOMEZ link
11/18/2013 12:19:56

Alejandro;

One of the objectives of writers is to elevate the game. We write about what we love, and we would love even more if it was done better.

Caliber and power are no substitutions for marksmanship and fieldcraft. Fieldcraft and marksmanship would be a better order, as a matter of fact.

While most of the forensical evidence that is often cited is usually good, it is also a matter of science, and therefore a little bit statistical: MOST of the times this and that happens . . . . In 90% of the cases such and such occurs. . . .

I believe that we, as hunters, are to hold ourselves to higher standards.

My very best mentor in the airgun hunting world was Mike Pearson, and his rule was the 10/10 rule: Prey had to completely expire in less than 10 seconds and less than 10 ft from the spot where it was hit. Otherwise it was NOT a GOOD hit.

In the search of completely complying with that rule is that I became a precision oriented hunter. And then it was that I discovered that there is no substitute to accuracy.

Bigger calibers and greater ft-lbs outputs are more forgiving, yes, but you need to hit at least REAL CLOSE to where you're aiming, and as we have all found out when testing extra-light pellets at 1,650 fps: they hit nowhere near where we want them to hit beyond the 30 yards line.

I am not too concerned with quick, clean kills from those shooters that use 0.25", 0.30" and 0.357" calibers at 50+ ft-lbs. Those shooters are advanced enough they do not really need to read me.
My concern is for the other end: those that are limited by LAW to 12 ft-lbs, or to smoothbore barrels and/or to 0.177" caliber.

Their best weapon is not their gun, but the knowledge they can derive from the information at hand.

Thanks for your comments and your links, very valuable!

Un abrazo!






Héctor

Reply
W1661e
4/4/2022 18:20:51

Good man. Top info. I deal with assault rifles at work on a daily basis. However due to our countries law I am using sub 12 ft/lb and this has taught me the importance of accuracy over all. A well placed shot is (in my opinion) better than a larger calibre when dealing with quarry. I actually prefer sub 12 air rifles than my works rifles. I don’t know why, I just enjoy the challenge. Cheers for the informative article. Keep up the good work.

Reply
Hector Medina
4/5/2022 10:41:31

Thanks for your kind words.

I assume you're in the UK?

Thanks for reading!




HM

Reply
James Wigg
4/5/2022 14:04:51

I am indeed.

Reply
Hector Medina
4/5/2022 15:32:52

Well, having spent 3 years in Manchester, I do consider the UK sort of a "third home".

BTW, the promised exploration of the terminal effects and the procedure to do it are mentioned here:

https://www.ctcustomairguns.com/hectors-airgun-blog/the-universal-pellet-is-here

Hopefully, you will have some spare time to go through it. You may find different results, and that is perfectly fine, but if you have the opportunity to test the "wet newsprint" expansion media methodology, your comments will be very rewarding for this writer.

Again, thanks for reading and all the best to Old Albion.



HM

Reply



Leave a Reply.

    Hector Medina

    2012 US National WFTF Spring Piston Champion
    2012 WFTF Spring Piston Grand Prix Winner
    2013 World's WFTF Spring Piston 7th place
    2014 Texas State WFTF Piston Champion
    2014 World's WFTF Spring Piston 5th place.
    2015 Maine State Champion WFTF Piston
    2015 Massachusetts State Champion WFTF Piston
    2015 New York State Champion WFTF Piston
    2015 US National WFTF Piston 2nd Place
    2016 Canadian WFTF Piston Champion
    2016 Pyramyd Air Cup WFTF Piston 1st Place
    2017 US Nationals Open Piston 3rd Place
    2018 WFTC's Member of Team USA Champion Springers
    2018 WFTC's 4th place Veteran Springer
    2020 Puerto Rico GP Piston First Place
    2020 NC State Championships 1st Place Piston
    2022 Maryland State Champion WFTF 
    2022 WFTC's Italy Member of TEAM USA 2nd place Springers
    2022 WFTC's Italy
    2nd Place Veteran Springers
    2023 WFTC's South Africa Member TEAM USA 1st place Springers
    2023 WFTC's South Africa
    2nd Place Veteran Springers

    Archives

    June 2024
    May 2024
    February 2024
    October 2023
    September 2023
    August 2023
    May 2023
    March 2023
    December 2022
    August 2022
    May 2022
    April 2022
    February 2022
    August 2021
    July 2021
    June 2021
    May 2021
    April 2021
    March 2021
    February 2021
    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    November 2019
    September 2019
    August 2019
    July 2019
    May 2019
    April 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    June 2018
    May 2018
    April 2018
    March 2018
    February 2018
    January 2018
    December 2017
    November 2017
    October 2017
    September 2017
    March 2017
    December 2016
    October 2016
    September 2016
    July 2016
    June 2016
    March 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015
    August 2015
    June 2015
    May 2015
    April 2015
    March 2015
    February 2015
    January 2015
    December 2014
    November 2014
    October 2014
    August 2014
    July 2014
    June 2014
    May 2014
    March 2014
    February 2014
    December 2013
    November 2013
    October 2013
    September 2013

    Categories

    All
    Events
    Gear
    Hunting
    Tests

    RSS Feed

Proudly powered by Weebly