Bob has written some awesome articles on pellet vs. slug expansion in HardAir Magazine. 👍🏼
Quote from: PaulFWI on November 11, 2021, 02:41:08 AMMomentum is not used to "push" the animal because the bullet *penetrates* it. I shouldn't have phrased that the way I did.I rest my case.
Momentum is not used to "push" the animal because the bullet *penetrates* it. I shouldn't have phrased that the way I did.
So, what happened here was that the *momentum* of my arguments done traveled thru the Internets and knocked you right off your chair!
Quote from: PaulFWI on November 11, 2021, 07:39:50 PMSo, what happened here was that the *momentum* of my arguments done traveled thru the Internets and knocked you right off your chair! No. Resting my case means I am confident that you have lost the argument due to my overwhelming argument, based on pertinent facts and logic. If you choose to carry on; then carry on
I've never shot slugs, so I can't offer any comment on their comparison to pellets. I grew up squirrel hunting with a .22 rimfire, so I'm very familiar with its use on squirrels. I've probably killed over 100 squirrels with a .22 air rifle, mostly shooting 18 g JSB pellets. From the beginning, I've been consistently amazed at its effectiveness on squirrels. It kills humanely, quickly, and out of all proportion to its energy created. I have assumed it is the result of the transfer to the squirrel of a large portion of its relatively little energy. Can't really explain it, but it is a proven killing machine on squirrels.
A SWC or something with a significant meplat should do more tissue damage compared to the steep ogive FX hybrids.
DJ,Pellets are nose heavy; thus naturally stable to fly nose first through air. For the same reason, they do not tumble in flesh, unless they strike bone at an oblique angle. Pellets recovered from game show mangled noses with hardly any damage to their skirts.Contrast that with bullets. If not for their spin, they would tumble in air. Even when spun fast enough to stay point first in air, pointy bullets (tail-heavy) tend to tumble on contact with thicker "fluids", such as ballistics gel and flesh; unless they mushroom to some degree. A mushroomed bullet is nose heavy and tracks straight, unless deflected by bone.For any given bullet construction, there is a minimum impact velocity to usefully expand a slug; especially to a proper "mushroom" shape. (Yes, it also depends on the target medium; and few gels are equivalent to meat. Also a squirrel is "softer" and lighter than a deer). That expansion threshold velocity is surprisingly low, for un-jacketed thin walled pure lead hollow point slugs. Matthias (JungleShooter) has compiled lots of useful data and images about the performance of hollow point expanding projectiles. I suggest you take a look at those.If we are talking about harvesting deer with a .45 caliber air rifle that shoots 400 grain bullets at 680 FPS muzzle velocity, then I would opt for a semi-wadcutter, rather than a hollow point spitzer. The entrance and exit hole diameter, and tract diameter and depth for the semi-wadcutter will be much more predictable, than for a conical hollow point bullet, that may or may not expand. Now, you might suggest a hollow point semi-wadcutter as a good alternative. Hard to argue with that. Whatever the projectile, it should at least reach the skin on the far side of the animal in broadside shots. I would argue that a full caliber wound track all the way through (including the skin on the far side) is better than a slightly larger hole that stops short of the skin on the far side, because the pass-through with a semi-wadcutter is likely to at least leave a better blood trail by bleeding more externally. This is probably very true, if the hole on the near side hide is small and able to close itself off - something more likely with a sharper conical bullet at subsonic velocity. Rather than argue bullet types in more than a general fashion, real results obtained with actual projectiles should count for more. Especially as a system. This includes the size and species of the animal, and the shot placement; on top of the detailed projectile design, material hardness and impact velocity. The barrel twist rate can affect the threshold at which a conical hollow point slug tumbles in the animal, if the impact velocity was not high enough to mushroom it enough to resist that. Blunt semi-wadcutters tend to track straight and resist tumbling, even without significant expansion.Tumbling may or may not produce enough damage to be effective (yes, it is spectacularly effective when it occurs with high velocity FMJ bullets, that have more than enough energy to pass through). This is because tumbling tends to include veering off course. If such a change in direction veers away from vital structures, then tumbling is less effective. The converse is also true. In any event, tumbling projectiles are likely to produce a mix of very fast and very slow kills - not a mechanism one should rely on.So, a slow semi-wadcutter, or a much faster hollow point bullet should both produce reliable results on deer. The latter by causing more damage to vital organs, at the expense of a second larger "bleed hole" to the far side. If I had to shoot a larger animal such as a moose, where heavy bone is likely to be hit, I would go with the solid semi-wadcutter rather than a soft hollow point. Else, hitting bone may limit penetration to the point of badly wounding the animal rather than killing it.People tend to stick with projectiles that have worked well for them before, under similar circumstances; even if there is something "better" out there. Not a bad strategy.
Here is the HAM article: https://hardairmagazine.com/ham-columns/airgun-slug-penetration-compared-to-pellets/
If "ogive" is a word, I'm in over my head.
Quote from: PaulFWI on November 11, 2021, 09:41:42 PMIf "ogive" is a word, I'm in over my head.LOL. Cue Jeff Foxworthy: "You might be a redneck, if......... "
You might have a meplat, if...
Another HAM article on slug expansion: https://hardairmagazine.com/ham-columns/more-fragmenting-slug-performance-data-its-devastating/Quote from: subscriber on November 11, 2021, 07:34:27 PMHere is the HAM article: https://hardairmagazine.com/ham-columns/airgun-slug-penetration-compared-to-pellets/
My head used to be an ogive. But I banged my head too many times against the sound barrier, trying to understand ballistics..... 😖 Now, my head has a meplat, it's spin-drifting (with a right-hand twist at 17"), and I lost some BC. 🤷🏻♂️
I still think the issue is most likely the FX hybrid slugs expand too much to penetrate well resulting in slower death for the bunnies. I just reviewed some tests by Steve Sally (sp?). It was of 22 caliber slugs but the FX only went 4.5 inches into the ballistic gel where the JSB went 9 inches.