caliber or power

[nervoustrig]

Okay so there’s no debate on the larger caliber being more effective. At least not where all the other parameters are held constant...projectile geometry, velocity, and point of impact.

The OP was making the assertion that the caliber isn’t the important thing, it’s the energy delivered to the target.

I see that my initial response didn’t adequately represent the fact I agree on that central premise. So let’s take the same .22 vs .25 example and wrap it with what I think are the relevant qualifiers.

Let’s just say the .25 is a dome and on impact it expands very slightly to .26. The .22 will deliver the same energy to the target if and only if it expands to the same .26 diameter. Essentially it must “plow the same trench” in order to be able to impart the same energy to the target. If it doesn’t expand, its frontal area will plow a narrower trench and therefore be unable to transfer its energy to the target. Granted if there is still flesh in its path, it will penetrate further than the .25 which may or may not be useful depending on what those downstream tissues happen to be, but that gets into manipulating other variables so let’s not go there.

So another way of saying this is...the .22 is as effective as the .25 if it can transform itself into a .25 on impact. 

Admittedly this is a bit of of a simplification because it will have to pass through some amount of tissue before it expands out fully. And there is undoubtedly some increased turbulence around the head as it flattens and plows through tissue, but again that’s just a pesky detail that shouldn’t detract from the basic premise.

 

[pcparmy]

I see what you are saying. But.....it doesnt bear out in real life to me that a 22 becomes a 25, and the 25 stays a 25.

watching video playback of the 25 slugs hitting the chest, shockwaves reverb from neck to tail. And they pass through both sides, at least out to 170 yards for me

My 22 slugs make a smaller shockwave, and i cant remember a time that it dropped a chuck on the spot with a chest shot . The 25 does about half the time under a hundred yards. They just scrunch up into a ball and bleed out.



So i agree if the 22 becomes a 25 its as effective as a 25 staying a 25 But when does it ever really? A 22 slug vs a 25 pellet? Back to apples and oranges.

 

[nervoustrig]

You hit the nail on the head. I was not making the case that it's likely for a .22 to quite literally become a .25 on impact. Only that hypothetically if it did, that would be the necessary condition for it to transfer its energy to the target as effectively as the .25.

 

[pcparmy]

Roger. Vehemently in agreement. lol

 

[Bullfrog]

Caliber, unless the difference in power is dramatic. 

For a while now I've argued that airguns kill like a bow. Your pellet or bullet is basically functioning as a broadhead. When you hunt with a rigid pellet or HP bullet, the pellet's skirt or bullet's rigid hollow point acts as a cutting edge like the edges of a fixed bladed broadhead. When you pellet or HP bullet is soft or shot at the higher end of sub sonic velocities, the deformity of the projectile is acting like a mechanical broadhead that spreads itself inside the target. The killing power of the projectiles lie in their cutting edges, not their energy dumps. The energy dump that most airguns deposit are negligible compared to a firearm and are on par with an arrow. So in other words, your 100fpe hp bullet is killing like a mechanical broadhead when it expands, not like a 1200fpe HP firearm bullet that's creating a massive shockwave when it hits.

More to the OP's original question and argument, this video I made is on point:





https://www.youtube.com/watch?v=xm5BF3UtCEg





I detuned my .308 Texan SS to shoot a near pure lead HP bullet with less energy than a HP .22LR supersonic round out the muzzle and to hit with about the same energy at 50 yards. The .22LR HP shot with 10-15fpe more energy out the muzzle and down range at 50 yards would have hit with just a couple foot pounds more than the .308, but the .308 airgun round did superior damage both in terms of expansion and depth of penetration. Caliber beats energy when the two are hitting at comparable energy levels. The physical properties of the projectile, not the energy, is more indicative of the damage. Because the damage is mechanicaly based, not energy based. 

Broadheads in every way except superficial appearance...

 

[tsmith]

All things being equal, (speed, pellet design) the larger pellet will transfer more energy on soft, fleshy targets. Take a 20fpe .177 and a 20fpe .22.. The difference in stopping power is pretty profound. Some would argue it’s partly a function of retained energy, and they’d be right. BUT, if those two projectiles arrived at their furry target with exactly the same energy, the larger diameter pellet will always deliver more “Thwack!” Hydrostatic shock, stopping power, whatever you want to call it.

One example of many I could give, is the time I owned 2 Benjamin disco’s at the same time. One in .177 and the other in .22. Both tuned to the HFT limit of 20fpe. ZERO question which one I’d grab to nail a backyard pest. It’s true, dead is dead, but that .22 put em on the ground instantly, hehe. 

HTH(?) 

Brian

I agree 100%

 

[Jheikkila]

One thing I never understood about the energy dumping thought stream. If you shoot a rabbit with a 10ft pound gun and don’t get a pass though they say all 10 ft pounds are dumped. But if you shoot a rabbit with 20 ft pounds and get a pass though you are overkill 10 extra ft pounds. The way I think about it you are never wasting energy because if even if you have a pass though the impact was more powerful. The first layer of skin was broken with 20ft pounds. The ribs where shattered with 20 ft pounds. I have cleaned rabbits that had lots of unusable meat because of the shock damage from pellets. Jelled up slime and blood from impact. I’m not saying that 20 is needed for hunting. I believe anytime your looking for performance 20 will do better than 10 given the same impact spot. And same caliber. 

 

[nervoustrig]

I get what you are saying but the ability of a projectile to impart its energy to the target is determined primarily by its area (established by the caliber/diameter) and the distance it travels as it plows through things of varying densities/hardness (skin, meat, organs, and bone).

For example let's say it takes 8fpe for a given pellet to go 2 inches through a squirrel broadside. If the pellet had 10fpe on impact, it delivered 8fpe to the squirrel. If instead the pellet had 20fpe on impact, it delivered the same 8fpe to the squirrel. The only qualifier to that is the extent to which the higher velocity pellet deformed on its way through...meaning it becomes a larger caliber and therefore operates over a larger area which enables it to deliver more of its energy to the target. 

For most pellets that difference is negligible. Granted we are seeing more and more options for expanding pellets all the time but they seldom have the 50yd small game/pest accuracy that many folks desire. Hollow point bullets and their typically elevated energy levels are a different matter.