Howdy all! I'm new here, so I'll give a quick background: I grew up in a relatively rural area, handled rifles and single-action revolvers. Purchased an HK P30 in .40 a couple years ago, and carry it regularly. It conceals well Inside-Waist-Band with most clothing, but during the summer I'd like something smaller; still planning for IWB, not pocket carry.
I've narrowed my sights down on the K9 (or 40), or possibly the MK9 (40). I've already ruled out the polymer Kahrs as the weight of the K isn't too much at all, and the grip is so much better. I would have considered a baby Glock, because I would love the way my friend's G20 shoots if the grip didn't feel like a rough brick -- that goes for every Glock I've held, so they're out, too. I really like the feel of Beretta's PX4 compact, and the rotating barrel intrigues me, but it's not enough smaller than the HK to justify it being my next purchase.
Lots of people say the .40 kicks too much in the small Kahr -- I had a chance to try out both a K40 as well as a P40, and while they were snappy, they certainly weren't painful or unmanageable. (I must admit, though, compared to them, shooting the HK felt like a gentle massage.
) I haven't been able to try a Kahr in 9mm, nor have I shot many 9s. I've probably put 30 9mm bullets downrange in my life.
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So I have two dilemmas:
1) K vs. MK. I'm pretty set on the K, because it's still tiny and the grip is so nice, but if anyone has compelling reasons why the MK is preferable please let me know. Is it really much less concealable or more comfortable for IWB in shorts and T-shirt? (I'm 5'11, 180 lbs, and the HK does well with at least 50% of my shirts.)
2) This is practically the 9 vs. .40 war, so skip this if you've had enough of it. Clearly, shot for shot, the 9mm is not more effective than the .40. That is, if e(x)= effectiveness of cartridge x, e(9mm)<= e(.40). If e(9mm) = e(.40), then 9mm is the obvious correct choice, as it is much cheaper to shoot, has less recoil, and allows higher capacity (in the Kahr, that is only 1 extra). But if e(9mm) < e(.40), which is very possible, I must ask by how much, and is it worth sacrificing the extra round? How to measure it?
Velocity doesn't mean everything, since heavier bullets penetrate better, even if slower. Energy and momentum are so miniscule, I ask myself whether they mean anything. Consider that 500 ft-lbs of energy (more than most semi-auto loads) is about enough to raise 1 cup of water by 1 degree Fahrenheit, or about as much energy as you use to take three walking steps. This is already such a small amount, I can't imagine 500 being meaningfully better than 400, or 200 (.380 ACP) for that matter. Momentum is obviously negligible, by Newton's third law.
I've spent hours researching ballistics charts for various calibers, read countless useless caliber war threads filled with lots of opinion and very little fact, studies that are mostly useless (*cough* Marshall/Sanow) and ultimately it seems the only objective, scientific data comes back to the FBI and penetration being the #1 most important factor in the elusive effectiveness equation, with expansion being a distant 2nd. If this is true, all the numbers boil down to penetration predictors, and it seems 9mm again is the best choice, for the reasons listed above, as the big three semi-auto calibers all have similar penetration/expansion in gelatin.
But defensive loads exist for the .380 that achieve almost as much penetration as the others, with good expansion, so why is the .380 not included as just as viable a choice? Perhaps because, even though ballistic gelatin approximates the body most accurately of substances that could be tested, it might still be marginal at best. Maybe, when striking bone for instance, the extra weight of a .40 makes a larger difference than the inches of gel suggest?
So this is the long thought process that has finally led me to strongly consider 9mm (even though it'd be convenient to have both my pistols shoot the same stuff), simply because it's cheap, with higher capacity than .40, and if the FBI's standards are to be believed, and ballistic gelatin is truly applicable to reality, modern 9mm is just as effective as .40, although I'm becoming agnostic about the quantifiability of projectile effectiveness.
Do any of you have knowledge of or links to sources that scientifically discuss the real basic elements of effectiveness? Penetration, expansion, mass, velocity? The correlation of gelatin with real shootings? After all my research, I'm pretty set on 9mm, but I still really like the .40, and more power does mean something (whatever that is), which makes me feel better. So I'm still open to being swayed back to .40.
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Thanks in advance for any answers and information, and, if you made it this far, for bearing with me. This is my first post, so I figured I could make it a little longer.
Final thought: I like the DA/SA of the HK, and with the long, heavy pull for DA, I'm completely comfortable carrying as I should, with one in the chamber. I'm a little nervous about the light trigger pull on the Kahr -- any advice or stories about that? Thanks again!
I've narrowed my sights down on the K9 (or 40), or possibly the MK9 (40). I've already ruled out the polymer Kahrs as the weight of the K isn't too much at all, and the grip is so much better. I would have considered a baby Glock, because I would love the way my friend's G20 shoots if the grip didn't feel like a rough brick -- that goes for every Glock I've held, so they're out, too. I really like the feel of Beretta's PX4 compact, and the rotating barrel intrigues me, but it's not enough smaller than the HK to justify it being my next purchase.
Lots of people say the .40 kicks too much in the small Kahr -- I had a chance to try out both a K40 as well as a P40, and while they were snappy, they certainly weren't painful or unmanageable. (I must admit, though, compared to them, shooting the HK felt like a gentle massage.
) I haven't been able to try a Kahr in 9mm, nor have I shot many 9s. I've probably put 30 9mm bullets downrange in my life. -------------------------------------------------------------------------
So I have two dilemmas:
1) K vs. MK. I'm pretty set on the K, because it's still tiny and the grip is so nice, but if anyone has compelling reasons why the MK is preferable please let me know. Is it really much less concealable or more comfortable for IWB in shorts and T-shirt? (I'm 5'11, 180 lbs, and the HK does well with at least 50% of my shirts.)
2) This is practically the 9 vs. .40 war, so skip this if you've had enough of it. Clearly, shot for shot, the 9mm is not more effective than the .40. That is, if e(x)= effectiveness of cartridge x, e(9mm)<= e(.40). If e(9mm) = e(.40), then 9mm is the obvious correct choice, as it is much cheaper to shoot, has less recoil, and allows higher capacity (in the Kahr, that is only 1 extra). But if e(9mm) < e(.40), which is very possible, I must ask by how much, and is it worth sacrificing the extra round? How to measure it?
Velocity doesn't mean everything, since heavier bullets penetrate better, even if slower. Energy and momentum are so miniscule, I ask myself whether they mean anything. Consider that 500 ft-lbs of energy (more than most semi-auto loads) is about enough to raise 1 cup of water by 1 degree Fahrenheit, or about as much energy as you use to take three walking steps. This is already such a small amount, I can't imagine 500 being meaningfully better than 400, or 200 (.380 ACP) for that matter. Momentum is obviously negligible, by Newton's third law.
I've spent hours researching ballistics charts for various calibers, read countless useless caliber war threads filled with lots of opinion and very little fact, studies that are mostly useless (*cough* Marshall/Sanow) and ultimately it seems the only objective, scientific data comes back to the FBI and penetration being the #1 most important factor in the elusive effectiveness equation, with expansion being a distant 2nd. If this is true, all the numbers boil down to penetration predictors, and it seems 9mm again is the best choice, for the reasons listed above, as the big three semi-auto calibers all have similar penetration/expansion in gelatin.
But defensive loads exist for the .380 that achieve almost as much penetration as the others, with good expansion, so why is the .380 not included as just as viable a choice? Perhaps because, even though ballistic gelatin approximates the body most accurately of substances that could be tested, it might still be marginal at best. Maybe, when striking bone for instance, the extra weight of a .40 makes a larger difference than the inches of gel suggest?
So this is the long thought process that has finally led me to strongly consider 9mm (even though it'd be convenient to have both my pistols shoot the same stuff), simply because it's cheap, with higher capacity than .40, and if the FBI's standards are to be believed, and ballistic gelatin is truly applicable to reality, modern 9mm is just as effective as .40, although I'm becoming agnostic about the quantifiability of projectile effectiveness.
Do any of you have knowledge of or links to sources that scientifically discuss the real basic elements of effectiveness? Penetration, expansion, mass, velocity? The correlation of gelatin with real shootings? After all my research, I'm pretty set on 9mm, but I still really like the .40, and more power does mean something (whatever that is), which makes me feel better. So I'm still open to being swayed back to .40.
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Thanks in advance for any answers and information, and, if you made it this far, for bearing with me. This is my first post, so I figured I could make it a little longer.
Final thought: I like the DA/SA of the HK, and with the long, heavy pull for DA, I'm completely comfortable carrying as I should, with one in the chamber. I'm a little nervous about the light trigger pull on the Kahr -- any advice or stories about that? Thanks again!
