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Alan's Corner / Re: Terminal Ballistics of pellets
« Last post by nervoustrigger on July 19, 2018, 07:10:11 PM »
Well, terminal ballistics has a rather narrow definition:

Quote
Terminal ballistics is the study of how a projectile behaves when it hits its target and transfers its kinetic energy to the target.

By this measure, a wadcutter wins the prize.  Certainly transfers more of its energy and produces more tissue damage.  The one caveat is that it must be moving with enough velocity to ensure some significant penetration.  In other words, if we were to stack the deck so a dome was moving just fast enough to barely penetrate, the wadcutter would fail to do so.

But of course that advantage quickly erodes as distance increases, and domes are quite capable of getting the job done when they icepick gray matter so wadcutters tend to have a practical range limit of 30 yards or so for the types of small pests we typically deal with...house sparrows, chipmunks, gray squirrels, etc.
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Alan's Corner / Re: Terminal Ballistics of pellets
« Last post by Alan on July 19, 2018, 06:11:50 PM »
If I didn't make it clear...

I just so happens, I believe, that the optimal shape of a pellet for long distance accuracy, also happens to be the best shape to deliver the best terminal ballistic performance. And, as I alluded to, the softness of the lead is part of the formula, but of less significance.

How's that?
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Alan's Corner / Re: Terminal Ballistics of pellets
« Last post by mobilemail on July 19, 2018, 03:44:55 PM »
Terminal ballistics aka "How I shot my chrony"   ;D ;D ;D

So what do you hope to learn from your study of terminal ballistics? 

Ballistics that provide the most accuracy?
Ballistics that provide the most range?
Ballistics that carry energy the most efficiently? (discounting solids, as discussed).

I'm kind of interested in when we change our description from diabolo to solid "bullet"?  For example, the JSB Monsters and H&N rabbit magnums really cross the line. 

Also, a comparison with heavy diabolos (Eun Jin?) and a solid of the same weight would be interesting.
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Airgun News from the Wire Services / Re: Five shot on Hank Aaron Trail
« Last post by mobilemail on July 19, 2018, 03:37:27 PM »
No we don't need idiots making our sport look bad.

Nor do we need anti-gun zealots overregulating airguns because of idiots. People forget that if the perpetrator had been using a gun, or even a hunting bow, there would likely be casualties.  The real truth is that this attack could just as well have been with a slingshot with pretty similar results.

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Airgun News from the Wire Services / CO2 Pellet Pistol
« Last post by Alan on July 19, 2018, 02:09:29 PM »
https://www.wkrn.com/news/local-news/police-2-arrested-after-firing-pellet-gun-at-guards-at-cheatham-county-factory/1306510820

If this keeps up, it won't be long until these replicas are treated as firearms, ordinance wise.
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No cure for STUPID ..... just another chapter in this countries MENTAL HEALTH CRISIS  :o

I feel so badly for the young lady who fell victim to his sheer stupidity !
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The Garage / Daystate PH6 moderator
« Last post by dgiannandrea on July 19, 2018, 09:52:23 AM »
Beautiful and showroom condition Daystate PH6. A bit quirky, but it is accurate and I love it for that.

I want to make it quiet. I don't know how the stock moderator is attached, therefore don't know how to remove it. It's all  beautiful and blued, attached to the rifle "permanently" back when BATF hadn't made up their mind about how nice a quiet airgun is. If the blued moderator cannot be removed painlessly I would rather just enjoy it as is.

Suggestions?
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Alan's Corner / Terminal Ballistics of pellets
« Last post by Alan on July 19, 2018, 08:28:35 AM »
Internal ballistics (what happens inside a weapon propelling a projectile), and external ballistics (the flight of the projectile after it leaves the weapon) are well known sciences. In fact, knowing just a few basics like velocity, the BC (Ballistic Coefficient), and the SD (Sectional Density) of the projectile, along with the ambient conditions, and one can closely predict the flight of any projectile.

Once the projectile in question reaches its intended target (assuming game), the number of variables increases to the point, that science has very little to do with the actual damage inflicted, lethal or otherwise. But that doesn’t stop folks from generating all manner of anecdotal evidence. One very good example is the use of the term, Hydrostatic Shock! Another is Stopping Power! Both of these terms, don’t mean much, especially in the world of pellets!

By pellets, I’m speaking of sub-sonic, diabolo-shaped (wasp waisted) projectiles, not bullets! If we were talking about the latter, here is the definitive, on-line treatise: http://www.rathcoombe.net/sci-tech/ballistics/wounding.html If you take time to wade through the material, you’d notice a lot of applicable material. However, the author is speaking of (for the most part) super-sonic projectiles. With few exceptions, pellets are shot at sub-sonic velocities. Therefore, my consummate opinion is, that pellets are in a class of their own, and that super-sonic data, gathered by whatever means, is not applicable!

While I was formulating my thoughts on this subject, I even thought about including a comparison between pellets and mini-balls, like those used during the American Civil War. But as I thought about it, mini-balls were really large (≥ .45 caliber), the use of soft lead alloys notwithstanding. In any case, the analogy isn’t applicable. Nonetheless, I believe pellet shape is very important!

At this point, there could be an in-depth discussion of the various types of pellets, but most have a finite use. Wadcutters are a good example, while they might make good hunting pellets at close range, their flight characteristics are not conducive to hunting game at longer distances. The same could be said for hollow points. Some may argue, but I consider PolyMags to be short range designs as well. This leaves us with the pointed and round nose pellets.

I’ve not had good luck with pointed pellets either, especially so in either of my .25 caliber airguns due to nutation. The primary cause for the nutation remains unclear. One of the brands I tried had longitudinal striations on the skirt. As a result, defection due to Magnus effect was more pronounced! Further, their kill ratio (by personal observation) is less than half of that of the round nosed pellets I’ve settled on. Perhaps it is because they tend to push aside tissue, rather than bore thought. I’ll leave that issue up to the readers.

One thing is for certain; The vast majority of airgun pellets are round nosed. And, I believe some of the reasons are not well known. For example, about four years ago, Bob Sterne posted a drawing on GTA (https://www.gatewaytoairguns.org/GTA/index.php?topic=68209.20) as shown below. Yes, there are variations in the actual ogive between manufacturers, but those differences are rather slight. Remembering that pellets are both spin and drag stabilized, it stands to reason that round nosed pellets provide better overall flight characteristics (at extended distances) than other designs. It has certainly been my experience that they do! Nonetheless, here’s something else to ponder.

What if it turns out, that round nosed pellets provide superior terminal ballistics than any other design? As I alluded to above, I believe they do! One might argue that some pellets are softer than others, and this (that) variation in hardness is the reason for the superior terminal ballistics. But I believe the hardness is a secondary issue, not the primary one. If you have differing opinions, I’d like to hear them.


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Contests, Give aways and more. / Re: Outstanding Member Generosity !
« Last post by steveoh on July 19, 2018, 07:06:14 AM »
Awesome generosity! I own two of these scopes and they really are an outstanding value. Add a big ole focus wheel and you are good to go.
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