Usually, when people talk about improving the 5.56, they talk about increasing the caliber, such as going to a 6.5mm round instead. But what about the other direction? Why not introduce a .19 inch caliber cartridge? 5.0x45mm would be pretty nifty.
>>28319062
It would be trash.
>>28319062
Why stop there?
>>28319069
>More capacity
>More MV
What's not to like?
>>28319062
Nifty because it's different?
>>28319091
>more velocity = better
You're the same retard that thinks that .45 is "lethaler" just because it has more energy. Ballistics isn't a numbers game where the larger number wins. There are several factors that speed and energy alone cannot lend insight into.
>>28319137
When you go above 3000 fps you start to get some very nice fragmentation that will fuck things up.
https://www.ar15.com/ammo/project/Fackler_Articles/wounding_mechanism_projectile_shape.pdf
>>28319189
And when your weight is light enough you lose penetration which is vital to fragmentation being effective.
Like I said, it's not a simple numbers game.
If you're dropping the bullet diameter to 5mm, why not lengthen the case a little and reduce the case diameter at the same time?
Smaller case diameter means you could stuff more rounds into a similar sized magazine.
>>28319199
faster rounds are better for more than just stoppan powah.
They're more accurate at longer ranges. They experience less drop and are affected less by wind.
>>28319137
All it takes to kill somebody is to punch a hole in their vital organs. Obviously, a bigger hole will do more damage in a shorter time-frame, but a 5.0mm projectile travelling at over 1000 m/s wil still impact with over 1600 joules, more than enough stop a man dead in his tracks. Meanwhile, you get the added accuracy of a higher muzzle velocity.
>>28319232
And if they're not heavy enough, they won't have penetration needed to hit vitals or deal enough damage to kill effectively. This is why things like .17HMR aren't used for anything. It's very fast, incredibly fast, but it has too little weight to be reliable.
>>28319235
Once again, ballistics isn't a numbers game. The higher energy cartridge isn't necessarily more deadly just based on energy alone.
>>28319232
They are not less affected by wind. If you want to defeat wind you need long skinny bullets with a boat tail
>>28319251
just make it even faster.
>>28319260
They are. The faster a bullet is, the less time it's in the air being pushed by the wind.
>>28319267
You have literally no idea what you're talking about.
>>28319273
Do you even understand force vectors?
>>28319289
>just make it even faster
Do you even understand ballistics?
>>28319267
>>28319289
The heavier a bullet is, the less effect wind will have on it, per newtons third law. This is an optimization problem, you can't just say "make it go as fast as possible" and expect results.
>>28319273
>this guy likes slow bullets
>>28319267
>The faster a bullet is, the less time it's in the air being pushed by the wind.
>>28319298
The faster a bullet is, the less time the wind will be pushing it. A bullet going 2000fps will be pushed half as much as if it was going 1000fps.
>>28319062
19 cal, bullet weighing 77 grains? Just a thought.
>>28319319
You'd have a bullet that;s over half as long as the case.
>>28319316
And it will be less affected by gravity as well. A heavier bullet will be more affected by gravity. A lighter, faster bullet will thus have a flatter trajectory, all other things being equal.
>>28319316
Yes, but what I posted is also true. Its an optimization problem. Just as there are limits to the size and mass of a bullet you can fire, there are limits to the velocity a bullet can be fired at from a man-portable device. There is an optimal value of mass and velocity to achieve maximum range, that will provide greater results than simply maxing the velocity and using a really really tiny bullet.
>>28319316
>>28319335
IS this real life? Go back to tumblr you noguns retards.
>>28319328
I'm pretty sure there's a joke in there about OPs mom...
In the early 80s they tried to change the propellant and use non necked cartridges to get more rounds in the magazine. Didn't go well unfortunately.
>>28319342
> gets legitimate argument points
> gets butthurt and yells about tumblr
Nah, bro, you go. And take your big, slow bullets with you.
>>28319359
This is some shit tier bait.
A light fast bullet is bad because it's going too fast without enough weight. It's fragile and will break on impact instead of shortly after. Light bullets that only use speed don't have good penetration.
>>28319366
Are you implying you need good penetration for a varmint cartridge? Fucking why?
>>28319342
>>28319366
>this guy is seriously STILL defending big, slow bullets
Is this your EDC?
>>28319366
>It's fragile and will break on impact instead of shortly after.
So then the round fragments, causing more tissue damage.
>>28319371
>suddenly brings up that it's for varmints
Nice back pedaling. You wanted a cartridge that was for long range and accuracy, neither of which are important in varmint cartridges due to their use.
>>28319376
Not if theres not enough material to cause tissue damage.
>>28319328
For a bolt action rifle I don't see much issue with this? I wonder what kind of BC that would have.
>>28319376
You don't penetrate if your bullet breaks BEFORE entering the body.
I bet you think keyholing is a good thing because it makes a larger entry wound, hm?
>>28319381
You're the one that brought up penetration. What the fuck are you on?
Been melting your own lead for all those big slow bullets you shoot?
>>28319062
They already have 17cal-5.56mm wildcats that don't require you to track down rare 5mm/19cal bullets for handloading.
>>28319396
What do you gain with your shitposting? There are 3 people, including you and me, in this thread. What's your endgame?
>>28319393
Each fragment will have sufficient penetration bub
>>28319411
Just like your RIP rounds, right?
>>28319401
Can't you at least admit that you're wrong?
>>28319415
Why do you shitpost on the slowest time on /k/? Are you practicing for later or something?
>>28319232
What is ballistis coefficient?
>>28319414
Those are moving so slow that they don't get the benefit.
That would like me pointing to FMJ
>>28319267
What is SD?
>>28319267
>They are. The faster a bullet is, the less time it's in the air being pushed by the wind.
this is fucking hilarious
I just came into this thread and see a whole lot of people speculating on shit they know nothing about.
Yall niggaz need to learn about our saviors Sectional Density and Ballistic Coefficient
>>28319444
>this faggot supports slow bullets
How about you take a hint from my friend the Force Equation, F=MV
>>28319444
then explain them you nigger
links or something
>>28319335
>it will be less affected by gravity as well. A heavier bullet will be more affected by gravity
WTF am i reading
>>28319393
Tungsten Carbide Penetrator Core
>>28319452
Sure thing.
https://www.youtube.com/watch?v=RCu8a5MynwM
TL:DR
Ballistic coefficient is rating of how aerodynamic a bullet is. A higher bc means it will maintain velocity over longer ranges (and therefore drop less and retain more energy), and be less affected by wind.
Sectional density is the weight of the bullet vs the diameter. A lot of weight in a small caliber cartridge means a high sectional density. The higher the sectional density the more it's going to penetrate. You can have a very small caliber bullet going extremely fast and not fragment into a million pieces, you just have to design it right.
>>28319451
It's F=M*A, you fucking retard. A bring accleration, you know the derivative of velocity.
>>28319596
*being
Apparently, I'm better at math than spelling.
>>28319451
Lol I do not "support slow bullets" unless you want to build an opr8r subsonic suppressed cartridge.
I support bullets properly designed for their specific applications.
>>28319639
So then what's wrong with a .19 bullet for an assault rifle?
>>28319664
I never said there was anything wrong with a .19 bullet, you have me confused with someone else.
What exactly are you trying to do with that rifle?
Target shooting, hunting, self defense? At what range? Do you need barrier penetration? What exactly are you trying to put down and at what range?
There is no do it all bullet
>>28319664
Assuming similar ballistics to the .17 Hornet, you'd get lighter magazines and reduced wind drift at the cost of:
1. Reduced barrel life (common to all high-velocity rounds) compared to the .223
2. No appreciable gains in trajectory over the .223
3. A SD so far below .100 that it's not going to penetrate tissue for shit.
>>28319685
>What exactly are you trying to do with that rifle?
An assault rifle must be:
1. Reasonably controllable on full-auto
2. Able to hold 20-30 round detachable magazines
3. Penetrate light body armor
4. Kill people effectively at 1-400 meters.
5. Light enough that it can be easily carried and operated by 1 person without assistance from others.
6. Long range (500+ meters) accuracy isn't essential, but it is a nice bonus.
7. Cartridges and magazines are light enough that one man can carry several magazines with him without being overburdened.
8. At least three different modes of fire: safe, single-shot, and full-auto.
9. Must fire an intermediate caliber (smaller than .30, faster than 600 m/s)
I could go further, but that's the basic concept.
>>28319335
You have no fucking idea of phisics. Everything is attracted to earth at the same accelaration 9.8.
When an object fall the only thing that can make then fall slower or faster are their aerodinamics capabilities. Velocity has nothing to do the gravity accelration still being 9.8 m/s^2. And less the velocity on the x vector...
>>28319877
A faster bullet reaches the target faster. This means that there is less time for the bullet to be affected by gravity. The result is a flatter trajectory.
This is EXACTLY why the 7.62x39mm falls in a steeper arc in comparison to the 5.56x45mm.
>>28319664
The main aspect of why we wouldn't use a 19cal bullet is that there wouldn't be any real gain from it. Yes, it would be faster, but by loosing mass you will loose penetration. There's a reason we use 308win instead of 243win. When in combat you're not going to be shooting at naked men out in the open, they're going to be behind cover, they're probably going to be wearing some type of armor, and the chance a bullet will go into the vitals before hitting at least a few inches of flesh and bones is slim. The bullet will most likely impact some part of the arms or shoulders before going into the chest so it must be able to survive going through that before it would have a shot at reaching vitals,and very light weight high velocity rounds are piss poor at doing that. It's about balance, you're going to want the speed for flat trajectory, range, and energy, but you're also going to want some mass behind that speed so your rounds don't shatter to bits when it hits an obstacle before getting to the vitals.
>>28319796
This guy knows what's up.
>>28319444
>uggg muh maths and logics
>>28319941
You are empirically wrong, though.
5.56x45, 62gr SS109 travels at ~3,100 ft/s. Effective range? 450 to 600 yards.
7.62x51, 147gr M80 travels at ~2,750 ft/s. Effective range is 600 to 800 yards.
.50 BMG, 1,813gr M2 travels at ~2,800 ft/s. Effective range is nearly 2,000 yards.
Basically, physics says you can suck it.
>>28319596
also, if we are going to be real autistic about this, you don't use f=ma for bullet energy. you use t=1/2MV^2 also grains and bounds are a measure of force, not mass. to get pounds into slugs(mass) you divide your weight in lbs by 32.2. to convert from grains to lbs. you divide your weight in grains by 7000.
>>28321308
He's not entirely wrong, and you're not entirely right.
There's much to be said for ballistic coefficients and twist rates for bullet stabilization, much of this concerning loadable bullet lengths. That's why a 6.5 Creedmore will easily outshoot a 7.62x51 at 1000 yards, but also why a .270 win will shoot flat as a board and super accurately out to 400 yards and then become less accurate compared to, say, a .308 after that.
"Effective range" isn't really useful here. That really only means the distance at which the projectile retains enough killing energy to be considered. A 5.56/.223 caliber rifle with the proper rifling and shooting a 77gr bullet (longer, G7 class, low BC) can snipe out to 1000 yards. "Effective range" is really just for soldier's idiot books, providing a baseline for trigger pullers and not for thinkers.
>>28321308
>Comparing different types of bullets to prove a point about assault rifle rounds
Might as well throw in the GAU8 while you're at it bro.
>>28319335
Gravity affects everything equally, tard.
Fun fact: if you fire a bullet from a perfectly horizontal rifle and simultaneously drop another bullet out of your hand from the same height as the rifle, they'll both hit the ground at the same time. They don't even need to be the same caliber.
>>28319596
One cannot have a velocity without an acceleration thus velocity is a derivative of acceleration. Furthermore, once a bullet leaves the barrel (or rather, very shortly thereafter) it is no longer accelerating so with f=ma bullets in flight have no force therefore they are harmless as long as you do no harm.
Checkmate Newton.
>>28322081
Try that with a lead ball and a feather dickwad you don't even have to shoot one . The force if gravity will affect them equally but air resistance will differ.
>>28322161
>What is negative acceleration.
>>28322081
>earth is a vacuum
DM11 shooting AR
>>28319298
Fuck you are thick and talking out your ass.
Heavier bullets are les affected by wind as they tend to have a higher ballastic coefficient then lighter bullets due to the cube square law.
>>28319062
>ACR Program: The Thread
>>28319399
Not to mention .204 Ruger and .20 tactical but hey its fun to watch all this hypothetical bullshit take place right
>>28319062
Why not utilize advances in technology and use advance propellants and straight wall design?
Equivalent performance, lower volume and lower mass.
>>28325340
straight wall design has its own problems with case extraction
>>28321308
You're using the wrong data and saying the wrong thing, because those three cartridges are incomparable.
But .50 BMG has an effective range that long because it still has energy at 1500m to kill things. You could conceivably hit the same target with the other two cartridges they would just do jack
>>28325340
straight walled cartridges are inherently less reliable in an auto-loading weapon than a tapered cartridge. the taper of the 7.62x39 cartridge adds to its reliability in the ak as it aids extraction.
>>28325340
>shit feeeding, shit extraction
>>28325412
Would it not be possible to create a cartridge with smaller shoulders?
>>28325412
>>28325432
my bros!
>>28325442
I dunno I only know for sure that rounds like .22 mag aren't used often for that very reason. As far as projectile dimensions and case shoulders blah blah I really don't know. Seems like you'd have a smaller bullet than a 5.56 is now, which is pretty small
>>28325477
Obviously we would not obtain the same "40%" more capacity numbers as the straight walled 223 but it still might make a difference
so what exactly causes the inferior extraction with straight wall cartridges?
>>28325477
>rounds like .22 mag aren't used often for that very reason
I thought it was because .22mag is rimfire
I would bet that if there was a 25 magnum it would be more common than 25acp is now.
