Is there really that much difference 115 or 124gr for the 9mm

I have always preferred a 124 gr bullet with around 1200-1250 fps for SD purposes. That is what NATO specs call for. AND real world 357 mag loads from 3" to 4" barrels are pushing a 125 gr bullet at 1250-1300 fps. That load has proven to be effective and 50 fps slower from a 9mm should do the same thing.

When I find it at a decent price I prefer 124 gr FMJ for practice. But I still shoot more 115 gr at the range because it is so pletniful and cheap. At typical handgun ranges I don't think it really matters that I use 115's for practice.

I've seen some testing of 147 gr loads at 1000-1100 fps that have me thinking that may in fact be the best option. That is what I prefer in my 9mm PCC. Some early 147 gr loads failed to expand at that speed and 147's got a bad rap. Newer bullet designs seem to have corrected that.

The 147 gr hardcast loads loaded by Buffalo Bore at 1100 fps penetrated over 60" of gel and out penetrated everything else tested, even 45 and 10mm loads. They never found the bullet, 60" of gel was all they had, and they didn't catch any of the bullets.

nettlle said:

Why would you change bullet weights/types dependent on the season?

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Theoretically, the 124 gr JHP should should provide better penetration through the heavier garments worn in colder temperatures. Also, I believe most law enforcement agencies use the 124 gr as well.

Only one real way to find out. Do the Paul Harrell Ribs and fabric penetration test

If you use good 115s and they don’t work, for whatever reason (miss/marginal hits), I doubt 124s would change the outcome.

nettlle said:

Why would you change bullet weights/types dependent on the season?

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In Winter cold weather climates heavier clothing can affect bullet penetration. I used to switch from a 9MM to a .45 on Winter for that reason. I still do but it because I have a nice shoulder rig for Winter wear.

If I had either in the gun, it wouldn't change the way I was shooting it. Changing the caliber wouldn't either.

Pick one you're convinced is better and you'll be happy.

If you really want something to worry about, I can probably come up with something.

I've no particular preference for bullet weight. I've been carrying a gun daily since 1974 and have been a police firearms instructor since 1976. I've carried quality factory JHP from 115 to 147 gr. I like the WW Silvertips for their low muzzle flash, violent expansion, and limited penetration as I've worked mainly in dense urban areas. I a mag of NATO ball if I needed penetration.

You will find slight differences in accuracy, muzzle flash, and perceived recoil between loads and bullet weights but nothing you couldn't live with.

Hugger-4641 said:

If I were going to switch ammo in the winter due to clothing an attacker might be wearing, I'd just go with a Swc or FMJ vs a hollow pt. I don't think there's enough difference in the two you mentioned to make any difference at typical SD distances.

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But why switch to a "solid" bullet in the winter, when the fancy JHP will either work as designed or just clog and act like ball ammo anyway?

As for which ammo to use, since most SD type 9mm loads are with 124-147 grain bullets, that's what I end up loading in my magazines. I'm a fan of +P and NATO-spec 9mm, but I also have a bunch of standard pressure 124 grain and 147 grain stuff too. My spare mags generally end up with NATO-spec FMJ, because it's the most reliable feeding and functioning, and clearing a malfunctioning pistol is the biggest reason I can envision for going for the extra magazine.

FWIW, I've chronographed the famous Winchester Ranger SXT 127 grain +P+ right at the advertised 1270-fps from a 4.5" Glock 17. I actually find .45 ACP hardball from a 1911 more pleasant to shoot. And the classic 125 grain .357 Magnum loading did 1400+ fps from a 4" 586, while replicating a hand-held flashbang. Most "generic" 115-grain 9mm FMJ loads trundle along around 1200-fps when I've clocked them, though it's been a while since I've checked any.

Kleanbore said:

The power factor was devised tor purposes other than predicting penetration.

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Semantics call it whatever you want it's still the momentum of the bullet.

Kleanbore said:

One could run a series of experiments with different velocities and masses of bullets, keeping everything else the same and using non-expanding bullets, and see whether, with each bullet, the penetration was more closely related to the velocity or to the square of the velocity.

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Been done over and over and yet here we are again with you in denial.

Kleanbore said:

Knocking down a pin or plate involves momentum. Cutting a hole in a plate involves energy.

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But it requires momentum for the bullet to pass thru the hole

357smallbore said:

Just to correct what I was saying. I was talking standard pressure loads of 124 and 115 not +p. Which one really works better was a general question. I've shot them both. I like them both but I was just wondering if it's a tit for tat only being nine grains difference. I know of the 115s faster the 124 penetrates a little deeper, but with all that said, does it really truly matter at the end of the day they both I believe will perform the job admirably. I just wanted to get thoughts on this

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I'd try both in your handgun and see which works best. A 125+/- in a 38 bore is known to be a good defense bullet. A 147 may even be worth a try in a short barrel. The lighter the bullet the more powder needed to build pressure and short barrels have limited burn time. Sometimes a heavier slower bullet in a short barrel is more accurate.

I've loaded everything from 90 to 147s in 9mm and find 125/124 the best all around shooter and performer for my uses in micro compacts through 16" carbines.

Do they penetrate a minimum of 12" in properly prepared and calibrsted Type 250A ordnance gelatin when fired from the same barrel length as your pistol?

If your well-placed bullet stops an inch short of the heart or a great vessel then it's as much of a "miss" as a poorly placed bullet.

SAAMI pressures for the standard 9X19 is 35,000 PSI. Plus Ps are 38,500 PSI. Super's are 36,500 PSI.

I think bullet construction is more important than pressures or velocities. A good, well constructed bullet that does its job and expands reliably is the most important variable.

wanderinwalker said:

But why switch to a "solid" bullet in the winter, when the fancy JHP will either work as designed or just clog and act like ball ammo anyway?

As for which ammo to use, since most SD type 9mm loads are with 124-147 grain bullets, that's what I end up loading in my magazines. I'm a fan of +P and NATO-spec 9mm, but I also have a bunch of standard pressure 124 grain and 147 grain stuff too. My spare mags generally end up with NATO-spec FMJ, because it's the most reliable feeding and functioning, and clearing a malfunctioning pistol is the biggest reason I can envision for going for the extra magazine.

FWIW, I've chronographed the famous Winchester Ranger SXT 127 grain +P+ right at the advertised 1270-fps from a 4.5" Glock 17. I actually find .45 ACP hardball from a 1911 more pleasant to shoot. And the classic 125 grain .357 Magnum loading did 1400+ fps from a 4" 586, while replicating a hand-held flashbang. Most "generic" 115-grain 9mm FMJ loads trundle along around 1200-fps when I've clocked them, though it's been a while since I've checked any.

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I'm not saying I would, but why else would he feel the need to switch from 115gr in summer to 124gr in winter?

Kleanbore said:

Denial?

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Yes the experiments have been done for over a century and yet somehow you would need them done again.
A 200gr solid bullet of the same shape and diameter at 1000 fps will out penatrate one that weighs 150gr at 1155 even though they have the same energy because the 200gr bullet has significantly more momentum.

Kleanbore said:

Yup. Any moving mass involves momentum and kinetic energy, and its velocity can only be changed by the application of force.

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And since it's an inelastic collision momentum is conserved as always but kinetic energy is not. Kinetic energy is converted to other forms the most significant with regard to wounding is elastic energy.

357smallbore said:

I just wanted to get thoughts on ththis

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And you did....

mavracer said:

Semantics call it whatever you want it's still the momentum of the bullet.

Been done over and over and yet here we are again with you in denial.

But it requires momentum for the bullet to pass thru the hole

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I use power factor to determine how hard a bullet is going to hit. I don’t have expensive ballistic gel, But I got a nice reloading room, and Chrono and other instruments.

Power Factor gives me a number to work with. Compare Mass vs Velocity when working up a load

Kleanbore said:

Whazzat?

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Elastic energy is the mechanical potential energy stored in the configuration of a material or physical system as it is subjected to elastic deformation by work performed upon it. Elastic energy occurs when objects are impermanently compressed, stretched or generally deformed in any manner.

Mark_Mark said:

I use power factor to determine how hard a bullet is going to hit. I don’t have expensive ballistic gel, But I got a nice reloading room, and Chrono and other instruments.

Power Factor gives me a number to work with. Compare Mass vs Velocity when working up a load

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Ballistic gel is not that expensive, I have a couple blocks. But all it is really good for is comparison between different bullets and loads. I can tell you for certain that how a 9mm 115gr fmj performes in a block of clear gel is not what they typically do in an animal.

Hugger-4641 said:

Ballistic gel is not that expensive, I have a couple blocks. But all it is really good for is comparison between different bullets and loads. I can tell you for certain that how a 9mm 115gr fmj performes in a block of clear gel is not what they typically do in an animal.

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You are a hunter! I know you know what kills animals best!

Hugger-4641 said:

I can tell you for certain that how a 9mm 115gr fmj performes in a block of clear gel is not what they typically do in an animal.

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And I can tell him for certain that what they may do in one animal doesn't in any way guarantee they'll do the same in another animal. Even animals of the same species. Or you can tell him. Either way.

Howland937 said:

And I can tell him for certain that what they may do in one animal doesn't in any way guarantee they'll do the same in another animal. Even animals of the same species. Or you can tell him. Either way.

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You are correct, too many variables. Angle of shot, density of tissue, skin, bone, etc.
Even two identical shots made inches apart can take different paths thru the animal and hit different tissue densities along the way. I can tell you that 9mm fmj's typically do not just pencil thru an animal's soft tissue and exit without expansion like many of the You Tube gel tests would seem to demonstrate. I have dug them out of animals where they didn't hit bone and still only had about 4 to 6 inches of penetration. I have also dug them out from under the skin on the opposite side 20" away from the entrance wound.

I think most people envision the typical SD scenario as a full frontal hit to the chest or abdomen of a human. This may or may not be the actual situation. Ballistic gel is never gonna give you an accurate example of any of the possibilities. It can show you how the bullet "might" or is likely to perform, but it can't account for the majority of the variables that are like to be present in any given impact.
What is true is that hollow points will generally transfer more of the kinetic energy into the target, and not as likely to exit without expansion, but this doesn't necessarily equate to being more lethal.