/k/ - Weapons

So, why are bottlenecked cartridges used so rarely in handguns despite many of the better performing ones being that way? 357 sig changes things a bit but what was the reason to not use them for so long? What do you guys think of .400 corbon?

And how viable are 10mm length cartridges in handguns for general purpose use? I've heard one issue with 10mm was that it was too big to fit into handle of comfortable size. If that's the case, can this issue be solved when using bottleneck cartridges like 9x25mm so that magazines are thinner in the front and allow better grip while keeping double stack? At what point do double feed magazines become impractical in handguns?

>why aren't bottlenecked cartridges used more

Because they are harder to design guns around and depending on the taper it can make conversions impossible.

A better performing round is less valuable to a military than a round that will allow for nearly double the cartridge capacity while being cheaper per unit to produce and increase the chances of an actual hit being made.

.45 died for a reason and it's because it's a bad handgun round for what you want a handgun to do in a military context; which is to provide suppressing fire for yourself so you can run away out of danger and let someone who doesn't have tens of thousands of dollars in officer training and command of a unit deal with the enemy.

This is why nobody uses pistols anymore, worthless in an actual military context.

Anything popular in the military will become popular in a civilian context because factories will be producing the ammo cheaper.

This is why 9mm is so popular when in a civilian defense situation where not spraying the area with 20 9mm rounds possibly killing (likely not) innocents would probably be a good idea, 9mm is cheap because it is produced more so people will use it over $1-$5 cartridges where you can barely get any training rounds in without taking away your beer money at the end of the week.

10mm would be useful to any organisation that is made up of mostly males who receive lots of firearms training but aren't supposed to use anything other than pistols.

Which is basically nothing in america at the moment.

Any situation that requires 10mm auto or S&W can easily be dealt with more effectively by using a carbine or a large capacity 9mm pistol which allows for more suppressing fire which is the actual important aspect of gun combat aside from actually hitting what you're aiming at.

>I've heard one issue with 10mm was that it was too big to fit into handle of comfortable size

Again for an organisation that employs mostly 6ft males that isn't a problem but again, that isn't a single instance of that except for the US marines who wouldn't use a pistol unless doing something sneaky beaky and in that situation they would use subsonic 9mm or .45 (realistically they wouldn't use a gun at all other than a backup)

The reason why i mention the military when you talk about civilian use is because the military rounds will be cheaper to buy, thus easier to train with, thus you will be more trained on them and more confident in a gunfight which is more valuable than having less training on a more powerful cartridge.

If you have little sword training it's probably better to pick up a dagger and not the massive broadsword that you don't know what to do with is what i'm trying to say.

>>624529

Also, you could make the pistol work with 9x19mm or 7.62x25mm by just swapping the barrel.

Again in a civilian CC or OC situation the cheaper the round is the more training you can do and the most effective you can be with the gun compared to less training but a "better" cartridge.

All discussion of what the better round is is completely irrelevant if it can't be made cheap enough to be trainable on.

You could make the wonder-cartridge that fit every single perimeter for the "perfect general pistol round" and nobody would use it unless it was as cheap or cheaper than what most people use today.

Threads like these that don't mention defining aspects like cost and ability to train may as well be gun designer larp threads.

>>624527

So its basically "the military can't bother with designing an effective round because it could be ok with a simple pea shooter and civilian market mostly follows the trend"?

>A better performing round is less valuable to a military than a round that will allow for nearly double the cartridge capacity while being cheaper per unit to produce and increase the chances of an actual hit being made.

Can you explain in more detail? Does bottlenecked design reduce the capacity of the cartridge? What are other disadvantages of the design if we compare a straight walled cartridge and its bottlenecked counterpart where their diameter, OAL and pressure are the same?

>>624534

It's probably more economic to choose a widespread cartridge for actually doing work but it's not the topic of the thread, which is comparing cartridge designs and exploring what determine their effectiveness. If you shilled muh budget choice just buy more ammo into every discussion about ammo engineering we'd be stuck wit hit forever.

>>624529

I was talking about 9x25mm dillon, not .38 super. It's a necked down to 9 10mm and it allows 2000fps with 90grain bullet.

>>624536

<can't bother with designing an effective round

>pea shooter

>pistol cartridge

>effective in a military context

>9mm

>pea shooter

>implying .45 also isn't a pea shooter

>implying any pistol round is going to ever be anything other than a pea shooter in a military context

>implying any pistol round that isn't considered a pea shooter will be useful in a military context

>implying it's as simple as just "bothering" to make a whole nation adopt a new military pistol round for no reason other than muh performance when we're in the middle of the most stringent military spending cuts in the last 200 years in every country

If this is actually how uninformed and unrealistic your expectations on how governments adopt new rounds are maybe you should en-devour to do research into the processes that different governments have when it comes to adopting new cartridges for their military.

<Can you explain in more detail? Does bottlenecked design reduce the capacity of the cartridge? What are other disadvantages of the design if we compare a straight walled cartridge and its bottlenecked counterpart where their diameter, OAL and pressure are the same?

I answered the first part of this already, it's harder to build a gun around because you have to take the taper into account when the cartridge gets booted out of the magazine and up into the chamber which a bottle necked cartridge will have problems with because the neck can get caught on pretty much everything and is just another angle you have to spend money designing around.

This is ok on military rifles because they generally have the space and extra materiel in the action to deal with this and having the gun made now with the cartridge we have right now is more cost effective than spending time tweaking either but for pistols every extra machine cut and every extra piece of metal you have in your gun is another dollar that company has wasted on pistols that don't really sell that well in todays over inflated market.

It's the same reason the US wants to adopt 6.5(6.8? i can't remember) rem, because then you can design a gun that doesn't have to deal with the bottle neck that .223 has, it will probably be more reliable and cheaper to produce because you don't have to devise some way of keeping the cartridge straight as it's booted into the chamber.

<diameter, OAL and pressure are the same?

The diameter of a bottle necked cartridge is by definition not the same all around as an actual straight wall cartridge, it's in the name.

And is OAL and pressure are the same on both cartridges then why not make a straight walled cartridge that's easier to design around and is less prone to jamming and malfunction?

<but it's not the topic of the thread

The topic is ballistics but OP specifically asked the question of why aren't higher powered pistol rounds used more today which is what i answered.

<which is comparing cartridge designs and exploring what determine their effectiveness.

The only determination for deciding how effective anything is is how useful it will be and how cheaply you can build it, the Chinese understand that people want things made today that will break next year not things made next week that will break 40 years from now when the whole reason you bought it in the first place ended 39 years ago.

The AK is popular and widespread because it fills both these conditions, it is made quickly and lasts a long time while being cheap, just like 9mm which is made quickly and cheaply and does the job just good enough.

Again the only thing that will ever, in the real world, determine how effective something is-is how it's used and how much it costs the average person to own.

Like i said nobody will buy your $5 super perfect round because they wont be able to train properly on it, making the whole discussion and design of it a complete waste of time.

If this is what you consider shilling then you're mentally fucked up, all i have done is tell you the reality of why cartridges are adopted and used and rise and fall in popularity.

Engineering isn't engineering unless you take cost into account.

Engineering without regard to cost is fantasy fiction writing.

>>624543

*as they have

>>624543

Thanks, that's very interesting.

Is kinetic energy a good measure of round's effectiveness? If so, does it make sense to reduce the weight of the projectile in a round to gains velocity and therefore increase energy? At what point does this stop being the case? Is insufficient penetration the cause of this and how do you measure it, especially when using different expanding ammo?

>>624542

>have to take the taper into account when the cartridge gets booted out of the magazine and up into the chamber which a bottle necked cartridge will have problems with because the neck can get caught on pretty much everything and is just another angle you have to spend money designing around.

>And is OAL and pressure are the same on both cartridges then why not make a straight walled cartridge that's easier to design around and is less prone to jamming and malfunction?

What are you talking about? Bottlenecked cartridges are well-known to be more reliable than straightwall cartridges, on account of their headspacing on the shoulder rather than the case lip.

>>624563

>>624563

>does it make sense to reduce the weight of the projectile in a round to gains velocity and therefore increase energy?

This was covered in the other thread, but you're thinking of energy the wrong way. You can't increase the total energy by decreasing mass because of conservation of energy; whether low mass or high mass, the projectile is being propelled by the same amount of powder, and the kinetic energy of the bullet will never be greater than the chemical energy stored in the powder.

I think you're assuming that there's a 1-to-1 tradeoff between mass and velocity, ie that halving the mass will double the velocity, and because energy has an (mv^2) term that implies energy would increase by 2, as velocity is squared. However, conservation of energy shows this is not the case; halving mass will only increase velocity by sqrt(2), and total energy stays the same.

>>624568

Thanks, i did read that thread but by physics knowledge is a bit limited and is mostly in different language.

>I think you're assuming that there's a 1-to-1 tradeoff between mass and velocity, ie that halving the mass will double the velocity, and because energy has an (mv^2) term that implies energy would increase by 2, as velocity is squared. However, conservation of energy shows this is not the case; halving mass will only increase velocity by sqrt(2), and total energy stays the same.

Ok, then why is there more energy in loads with lighter bullets?

>>624569

Correction:

maybe i think of different "energy" but here's the data i'm looking at(i'm using the cartridge because there're less different brands compared) https://en.wikipedia.org/wiki/9%C3%9725mm_Dillon

Bullet mass/type Velocity Energy

90 gr (6 g) Gold Dot JHP 2,100 ft/s (640 m/s) 881 ft⋅lbf (1,194 J)

95 gr (6 g) FMJ 2,000 ft/s (610 m/s) 844 ft⋅lbf (1,144 J)

115 gr (7 g) Speer Gold Dot JHP 1,800 ft/s (550 m/s) 827 ft⋅lbf (1,121 J)

125 gr (8 g) FMJ-FP Match or Speer Gold Dot JHP 1,700 ft/s (520 m/s) 802 ft⋅lbf (1,087 J)

147 gr (10 g) FMJ-FP 1,495 ft/s (456 m/s) 730 ft⋅lbf (990 J)

>>624569

>>624571

>Ok, then why is there more energy in loads with lighter bullets?

I can't answer that intelligently as I haven't looked deeply into the details of different 9mm loadings and how energy is transferred to them. However, assuming that all of your examples use an equivalent powder charge, you have to remember that in the real world, there are lots of things besides the projectile's mass and velocity that can determine final energy: the friction between the bullet and the barrel, the temperature and humidity that day, the elevation at which the shot was taken, drag function of the different bullets, and so on. When you take all the complicating variables into account, that can explain the differences in total energy.

>>624579

Yeah, i also thought of that, maybe it's less effective to transfer energy into speed with heavier bullet as well. It's just no matter where i look it's that higher velocity loads carry more energy than heavy bullets based, aside from some loads from different manufacturers that just seem mild and don't compare to similar weight ones. Heavier bullet loads also recoil harder so maybe it's about that and conservation of energy?

>>624534

>All discussion of what the better round is is completely irrelevant if it can't be made cheap enough to be trainable on.

Completely untrue if you reload. 10mm is a reloaders cartridge.

>>624536

>9x25mm dillon

Then specify it better, simply giving the nominal measurement of a cartridge can be rather confusing.

>not .38 super

The measurements of that cartridge would be 9x23mm. Or 9x23mmSR to be a bit more precise. But even then you'd have to add its non-metric name to differentiate it from .38 ACP.

>>624751

.38 Super technically is .38 ACP, like .45 Super technically is .45 ACP.

>>624751

Yeah, sorry, my bad. I just forgot about that one and dimensions of x23.

>>624523

Wait wait wait. .45 S&W? What?

>>624758

It's .40, OP just has a typo.

>>624772

Yeah, i downloaded it that way and never even noticed.