Why didn't they just add the steel bottom to 556 and 308 Posted on March 9, 2023 by PrepHole Contributor Why didn't they just add the steel bottom to 556 and 308
wasn't tacticool enough looking, also because it made sense
then you might put your 86000psi 5.56 into your m4
This is the right answer, but what they should have done is fuck with the dimensions just enough so as to prevent chambering in legacy firearms. But still retaining the same size and weight of the 5.56.
Would have made a lot more sense than the big, heavy, and harsh recoiling 6.8x51.
The army/govt provided the bullet though, and the 308 case was the smallest that could achieve the desires velocities, so whatever. Should have been a .224 though. Or like a 6mm optimum from a 5.56 case
The whole point was to be able to penetrate body armor at long ranges retard. Yeah, smaller and lighter projectiles will recoil less, but they struggle at retaining energy at long range. Velocity without the inertia to retain that energy is useless unless you are operating within a vacuum.
>tfw you'll never have a 77gr 556 ripping out of a m16a4 at 3500+ fps with the insane pressure
We really fucked this up, we had greatness and perfection right at our fingertips.
you could have had 55gr at 4,000 FPS from a 7lb rifle but noooo manlet operators had to have their way
Imagine the sound of that flying by probably have some interesting effects on the report
potentially, also could've just stuck with 308 with the modified case lobbing 178gr smks at 3k+ fps and you got a mobile poverty 300winmag
>Add steel bottom to .308
They sorta did. 6.8 SIG is just .308 with a fancy schmancy new case design, necked down to 6.8mm, because the US developed a good 6.8mm projectile and wanted it in their new rifle.
>why not do that to existing calibers?
Because either you use the higher pressure capability and risk putting it in older rifles that can't take the pressure (KABOOM) or you don't use that pressure, in which case, why bother? Using different projectile diameters makes sense to prevent this, so 6.8 SIG is a good idea, as would be a 6mm, high pressure version of 5.56.
I said it many times.
You can make supercharged 5.56 (lets call it 5.56super) reverse compatible with 5.56x45.
Make it with long ogive VLD bullet (you need it anyway for good from factor and BC). make 80K psi hybrid case. Sometheling like 65 grain 3300 FPS from 14.5'' with better BC than 7.62x51 M80.
New long 5.56super wouldn't fit into old 5.56x45 mags so risk of old guns cabooms is very low. New 5.56super guns with new mags can use old 5.56x45 ammo. That would smoothen transition and reduce cost of training that can be done with old 5.56x45 ammo stocks
But that would actually be a good idea and we all know that the guys in charge of military procurement are allergic to good ideas
This would mean destroying the STANAG mag standard though.
STANAG mag and limits of the 5.56x45 round OAL is largest obstacle that holds 556 performance down. Basically all new AR-15 based rounds is how to fit long ogive bullet into STANAG mag (by cutting down case length)
my thoughts exactly. the OAL restrictions of the AR-15 magazine are the biggest hurdle in universal cartridge development of the last 60 years.
Maybe they can fit in 308 cases.
Then we can make a new even bigger mag for 308 super that can fire 30-06, then we make an even bigger platform for 30-06 super magnum….
Not him, but it’s a small price to pay for what the new round provides, I.e. replacing 5.56 and 7.62. It is an arbitrary and unnecessary constraint too. You’re gonna have to build new guns anyways, just make the magwell a bit longer and make new mags. The world will adapt.
That sounds like a really good idea. I’ve been messing with the idea in my head of a modern 5.56 FABRL. Basically the 5.56 FABRL, maybe based on an every so slightly wider case like the 350 legend’s, but with a heavy for caliber, full-mass projectile, with an even better shape (original was flat-based), slightly longer (~2.4” OAL), and retard pressures. The more I play around in ballistics computers the more apparent it becomes that such a cartridge could very well be a single unifying cartridge to replace everything currently in service. It never occurred to me that the longer OAL could enable reverse compatibility without the risk of kaboom. But you know some retard is gonna single load it in his bolt gun or whatever and blow it up, or a hand loader is gonna load regular 55/62gr bullets in to 2.26” OAL and blow up his AR.
Another thing worth a mental masturbation session is the 6.8 fury-ification and FABRL-ization of the British 4.85x49. It’s a 5.56 necked to .197 or something like that. Basically retain its ballistics but in a much smaller package and with turned copper projectiles with a very low form factor.. Something small enough that it can be chambered in an MP7-type weapon.
>But you know some retard is gonna single load it in his bolt gun or whatever and blow it up, or a hand loader is gonna load regular 55/62gr bullets in to 2.26” OAL and blow up his AR.
You know that if some retard is trying that hard to win Darwin award let him lose fingers.
BTW SAAMI established proof loads pressure as 1.3 of the average pressure (gun needs solid safety overhead for safe use with real word possible spikes of teh pressure)
So 80K psi would be around proof load for 60k PSI "normal gun". Most probably it wodn't go kaboom. There can be (and is allowed by proof test) gas leakages and primers pops but no gun damage. Of course using over long period proof load tier rounds in teh gun would damage it but this is very high levels of trying Darwin award.
Why didn’t they just make lacquered steel cases?
I think I have seen them steel cased too
Because that would actually make sense.
>rebarrel old rifles with better barrels
>go to a 68-75 gr 5.56
>tungsten tip with tool steel backer
>crank pressure up to 82,000 psi
>semi fluted chamber for ease of extraction
What was wrong with all-brass?
brass too week to handle the pressure
>Stainless steel has a significantly higher yield strength than brass, allowing the engineers to use higher maximum average pressure (MAP) chamber pressure levels.
when you have bubba's pissing hot loads like the new meme cartridge, there is still significant gas pressure in the chamber during extraction
that pressure keeps the walls of the case welded to the chamber, because the brass hasn't had the chance to shrink back to its regular dimensions
if there's too much of this sticking pressure you get ripped case heads, which steel is obviously less likely to do
When inside the chamber, the brass walls are pressed against the steel of the barrel and that's what keeps the case intact.
However, the case head has to stick out of the chamber just a little in rimless cartridges so that you can extract. The process of drawing and ironing a brass case hardens the brass, the final annealing is done in the neck and shoulder area, and the case head is the thickest section of the cartridge. The unsupported chamber issue that caused the Glocknades and the "Glock bulge" is an example of the brass having to hold pressure - it deforms and can fail at high enough pressures, venting everything into the gun and kabooming it.
By increasing the 6.8 pressure to nuclear hot loads that will kill you, that portion of the cartridge that has to stick out of the chamber but isn't touching the bolt would create a failure point and banana-peel the upper. By switching the case head for a steel piece, the steel becomes a pressure-bearing structure itself and prevent case failure.
Thing is case is not supported from all sides.
Pressure that pushes case to sides is not a problem. Case walls are supported by gun barrel and they are monolith.
But case head is not. It has holes in it. And if enough forces is applied it collapses (usually around primer hole that is largest hollo wpart, primers start to popping out first). Imagine there is hydraulic press that pushes case head down from inside,
Case material strength is what holds case head from collapsing. Making that area from stronger material than brass (high strength steel) makes it able to hold larger force and pressure.
probly cause a 5.56 bullet wouldn't be heavy enough to not destabilize.
Because sig didn't bribe DOD officials to do that