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JungleShooter
(@jungleshooter)
Joined: 2 years ago
Posts: 148
July 12, 2020 03:04:35  

Slugs — Testing How Much They Expand and How Far They Penetrate

 

Slugs for airguns won’t ever replace pellets.

But they aren’t just a fashion, either.
Slugs easily cut wind drift by more than half.
And at longer ranges they hit quarry with twice the energy.

Those are reasons enough that I want slugs (not the slimy ones, though if they are cured with lemon and served with yam and hot chili peppers, they are quite good!).

 

 

The Benefits of Hollow Points

But almost all commercially available slugs come as hollow points – and for a reason. The hollow point is supposed to expand upon impact and make a larger permanent wound cavity. This is good if your quarry’s kill zone is rather soft and fleshy, as a bigger wound produces a higher rate of DRT’s (over the F&D’s and R&D’s*). (However, if your quarry’s kill zone is a big head protected by tough bones, penetration is probably more important than expansion.)
*[F&D = fly & die  |  R&D = run * die]

 

If the hollow point projectile (slug or pellet) increases in diameter, so does the impact area, and so does the volume of crushed tissue as the projectile bullies its way through the quarry – leaving the permanent wound cavity.

 

For example: A .22cal projectile (slug or pellet) that expands to .295 increases its impact area by 66%.
And at that increase, even a 1½"-short wound cavity therefore increases by 85%!  85% more tissue crushed!
[Metric: A 5.5mm projectile expands to 7.5mm. Even a 4cm-short wound cavity is thereby increased by 85% – resulting in 85% more crushed tissue.]

Also worth considering is that a blunt tip in all likelihood does more damage than a domed or pointed tip. So, all other things being equal, wadcutters, unexpanded hollow points, and wide open hollow points (in this order) will crush soft tissue more than domed or pointed projectiles (that will tend to slip and slice through tissue).

 

 

What Helps the Hollow Point to Expand

After seeing the often poor performance of hollow point pellets – I wanted to know what expansion I could expect from hollow point slugs.

 

Bob Sterne (HardAir Magazine and GTA) published some very insightful articles and posts about the subject (cf. links).
https://hardairmagazine.com/ham-columns/bob-sterne-discusses-hollowpoint-slug-design/
https://www.gatewaytoairguns.org/GTA/index.php?topic=174584.msg155979642#msg155979642

Just to summarize Bob’s excellent discussion:

Some of the attributes that support expansion of a slug are as follows:
• larger HP opening
• thinner walls of the HP cup
• softer lead
• deeper HP cup
• slits (predetermines tearing points) open the HP in petals
• harder impact material (animal flesh is softer than play-dough is softer than clay)
higher impact velocity! (as the tests will show, depending on the impact velocity the HP will “work” – or not expand)

 

 

HP Projectile Tests
Data on HP slug expansion is still scarce, but in the following posts I’ll share the Projectile Expansion and Penetration Tests .22cal that I’ve found so far.

 

Take the test results with a grain of salt (or a 22-grainer of lead if you like). As more test data becomes available some tests results might prove to be too optimistic, or pessimistic.

 

Some Benefits of the Test Results for the Shooter
• You will note in the tests that depending on the impact velocity the HP will “work” – or not expand. Knowing the muzzle velocity of a slug that your gun likes, you can do some simple ballistics to figure out at what the maximum range you still can expect reasonable expansion in the quarry.
• If you have the choice of several slugs that your gun like, based on the test results you could choose one that has better expansion, or choose a lighter (=faster) slug.
• If you wanted expansion at farther ranges, you could increase the power of your gun based on your ballistic calculations.

 

I thank all the airgunners who have run these sometimes very time-consuming tests, and for putting them out there for us so we could learn from them. THANK YOU!!  

 

Matthias

 

 

 

An Overview and Some Background of the Projectile Tests in this Thread

When sifting through the projectile tests (PT) I decided to leave out play-dough, clay, and water as ballistic mediums as they exaggerate HP expansion. Reading what terminal ballistician have written, I considered ballistic gel, ClearBallistics.com gel, glycerin soap, wet newsprint, and of course… – real quarry (dead or alive)!

 

The testers often do not give specific details of their test protocol (which kind of ballistic gel they are using), nor do they give exact data (impact velocity) or measurements (expanded size of the slug). I had to do some ballistic calculations and often measure the proportions of the expanded slugs in the images in order to arrive at the data as presented below.

 

All the tests include the following:
• a test designator, PTXXX (where XXX is a counter; PT = projectile test)
• the ballistic medium
• impact velocity, and impact energy
• expansion and/or penetration (in imperial and metric)
• source (and notes)


Quote
JungleShooter
(@jungleshooter)
Joined: 2 years ago
Posts: 148
July 12, 2020 03:07:11  

Projectile Tests. PT027. Steve Scialli (AEAC) (2020).

-Ballistic Gel Calibrated.- 40-41FPE.

NSA 20.2 @841fps + NSA 17.5 882 + N&N 27 770 + JSB 25 783 + FX 22 823

 

LINK (just add www. to the front of this):
youtube.com/watch?v=SJZNGszt0E4

 

Projectile Tests. PT027.  Steve Scialli (AEAC) (2020).  Ballistic Gel DIY B.  40 41FPE. NSA 20.2 @841fps + NSA 17.5 882 + N&N 27 770 + JSB 25 783 + FX 22 823. 01

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JungleShooter
(@jungleshooter)
Joined: 2 years ago
Posts: 148
July 12, 2020 03:07:52  

Projectile Tests. PT021. Donnie Reed (Baker Airguns) (2020).

-Ballistic Gel.- 46-52FPE.

H&N 23 @990fps + JSB 25 962 + NSA 23 974 + FX 22 974

 

Video: LINK (just add www. to the front of this):
youtube.com/watch?v=9vlQuaAFBIo
Text: LINK: https://www.bakerairguns.com/general/22-caliber-airgun-slug-shootout-jsb-k-o-slugs-first-look/

 

Projectile Tests. PT021.  Donnie Reed (Baker Airguns) (2020).  Ballistic Gel.  46 52FPE. H&N 23 @990fps + JSB 25 962 + NSA 23 974 + FX 22 974. 04. LosRes

 

 


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JungleShooter
(@jungleshooter)
Joined: 2 years ago
Posts: 148
July 12, 2020 03:09:21  

Projectile Tests. PT028. Steve Scialli (AEAC) (2020).

-Ballistic Gel Calibrated.- 16-26FPE.

H&N 27 @658fps + J Dm 763 + NSA 20 737 + Hades 667

 

LINK (just add www. to the front of this):
youtube.com/watch?v=sRyg8kIL-ys 

 

Projectile Tests. PT028.  Steve Scialli (AEAC) (2020).  Ballistic Gel Calibrated.  16 26FPE. H&N 27 @658fps + J Dm 763 + NSA 20 737 + Hades 667. 01

 

 


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Hector J Medina G
(@hector-j-medina-g)
Member of Trade
Joined: 3 years ago
Posts: 458
July 12, 2020 07:30:57  

As usual, very interesting, Matthias, thanks!

 

IF you have the time, perhaps you could read this, especially the section on "Terminal ballistics", please?

 

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

 

Thanks again!

 

 

HM


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JungleShooter
(@jungleshooter)
Joined: 2 years ago
Posts: 148
July 12, 2020 11:54:23  

Hector,

your careful researching and testing on anything airgun is simply GREAT! 😊 

 

I read that article a while ago, and I wished people would replicate your study with my preferred caliber (.22).

I have saved your article as PDF in my list of .177 Projectile Tests – if I ever get into .177.  As I stumbled on so many .177 projectile tests in my search for .22, it was easy to just copy and paste the URLs for future reference....

 

Matthias

 

 

 

 


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Hector J Medina G
(@hector-j-medina-g)
Member of Trade
Joined: 3 years ago
Posts: 458
July 13, 2020 18:52:19  

@jungleshooter

Thanks for your kind words.

Keep well and shoot straight!

 

 

 

HM


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JungleShooter
(@jungleshooter)
Joined: 2 years ago
Posts: 148
July 19, 2020 15:48:08  

Projectile Tests. PT018.

GunPowder&AirPower (2019).

-Ballistic Gel 20% – c. 5cm Thick.- 18,36FPE.

NSA 23 @842fps + Hades 715

 

LINK (just add www. to the front of this):

youtube.com/watch?v=f6jsPP3Z9Fg

 

 

Projectile Tests. PT018.  GunPowder&AirPower (2019).  Ballistic Gel 20percent – c. 5cm Thick.  18,36FPE. NSA 23 @842fps + Hades 715. 06

 

 

 


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