Justin Tyme posted:

Has there been any research into nonmetallic artillery round casings, like an epoxy granite type material using various sized ball bearings held in a plastic matrix? It seems the bottleneck to ramping up round production is it requires molten casting and machining facilities which is capital and energy-intensive.

I would imagine this would be difficult to produce a consistent product though considering how hard it would be to get repeatable CG/MOI characteristics, which would mean bad ballistic performance.

DJJIB-DJDCT posted:

You're more than welcome to run a calculator comparing the form factor of 175mm projectiles against 155mm

Apologies for the lousy scans,




and here's the comparable 155mm



The 175mm was achieving 33km without rocket assist or base bleed at a time when the most impressive 155mm guns (not howitzers) could barely crack 20km.

Trying to extend the range of 155mm because of the quest for a universal gun(-howitzer) rather than using the last true gun in the US inventory is... to put it mildly, a tremendous waste of resources. There is no reason to struggle against the upper limits of internal and external ballistics and gun carriage design, rather than, get this - simply using a larger projectile with better ballistics.

mlmp08 posted:

Thanks, this supports my argument. 203 and 175 never had a range of 70km. The US continues to debate whether or not the 70km range 155mm is worth it or not.

KomradeX posted:

Was it this thread or the Ukraine thread were we talked about the US being unprepared for how costly a peer air war actually is? Because I was just reminded of something I read earlier this week where a guy was talking about how he had a harder time connecting to Masters of the Air, vs Band of Brothers jjst for how relentless, grim and unavoidable all the deaths were why Band of Brothers was more dramatically satisfying with their deaths. Like fighting Iraq for 20 years has really hosed with our preceptions and I think in a way history has been revised to reflect that to where people downplay our air losses.in Vietnam. It really has lost all touch with reality

DJJIB-DJDCT posted:

Jfc.

Cerebral Bore posted:

also if the us wanted to move an artillery shell 70 km they'd just send in mlp and tell him that it's actually a set of goalposts

Cerebral Bore posted:

also if the us wanted to move an artillery shell 70 km they'd just send in mlp and tell him that it's actually a set of goalposts

DJJIB-DJDCT posted:

The entire idea of a "universal gun" was never due to the qualities of 155mm, I'll remind you that was a WW1 howitzer projectile - with inherent limits on sectional density and gyroscopic stability. It was selected by NATO almost entirely due to the emphasis on DPICM - which could not be used in high velocity guns anyway, because of the high stresses acting on container projectiles, and was not deemed useful in 105mm gun-howitzers. 155mm projectiles accelerated slowly enough that the container would not break to pieces.

That was a very, very specific situation - the Fulda Gap. There was nothing inherent about the 155mm that makes it a good, or even suitable, choice for use as a light field gun (replacing 105mm) or any kind of long range system. The weight of gun and carriage required is barely worth it at extended ranges considering the expense to deliver less and less explosives (shell walls must be thicker to accelerate to extended ranges, unless basebleed or RA are used... which reduce the space available for fill even more).

I'll add that the universal gun-howitzer concept was built entirely around the M109, a vehicle provided to NATO en masse so that it could be used in a CBRN contaminated battlefield and keep up with mechanized forces while protected under armour. Almost none of that applies to the current generation of guns after the M109. Outside of the Fulda Gap, what are we doing here?

The other reason planners of the late 70's and 80's wanted the 155mm projectile was for guidance, initially laser, later GPS. Here, again, the reason it was chosen in the first place points to the limitations. 105mm projectiles were too small, so we can quickly move beyond that. Higher velocity guns would shake the guidance units apart, they could not withstand acceleration. Only, we still see very high failure rates in the (relatively) slowly accelerating 155mm Excalibur and Copperhead. This was justifiable in the context of WW3, as was the greatly reduced capacity. Now, if you're talking about a guidance unit and RA or base bleed - because the same slow acceleration the prevents the DPICM container from breaking apart or the guidance unit from breaking (more often) also limits range - you are delivering an actual amount of explosives that pound for pound, considering the cost of the gun, carriage and projectile, is almost unjustifiable.

Every single one of these applications of 155mm beyond a certain point becomes more expensive and less useful as they stretch the calibre beyond any common sense. If the requirement is to deliver HE, WP, Illum, Smoke, and DPICM in a variable range band at either gun or howitzer trajectories, that was satisfied by the mid 70's. The idea of a super gun that can be all things to all people at absurd ranges will only lead to more expense in gun, carriage and projectile, while reducing performance in terms of weight of fire delivered to target and certainly in terms of cost effectiveness.

People have forgotten what the calibre is for and why it was adopted in the first place. Imagine if this much effort went into making sure .30-06 was a viable extreme range precision cartridge into the 21st century, and a lightweight assault rifle cartridge, and a duplex or triplex projectile.

For mortar bombs, yes, for anything else, no, it could not withstand firing and be economical and have the same capacity as steel equivalents.

DJJIB-DJDCT posted:

“No one improved projectiles that were dropped to chase universal calibre fairies” is not an argument against the projectile, or laws of ballistics, but the same theory that underpinned it.

If they wanted to achieve those ranges, they should not have decided to universally adopt 155mm.

mlmp08 posted:

That you need to practice and organize to be successful for wet gap crossings. Which is less a lesson from Ukraine, and more a constant of warfare since forever, though tactics and tech change.

DJJIB-DJDCT posted:

Jfc.

DJJIB-DJDCT posted:

Is your argument against ballistic coefficients and sectional densities, or what?

Mister Bates posted:

I don’t think we can expect to see WW2-scale losses of aircraft ever again just because nobody fields that many aircraft anymore, but the US has internalized this idea that a combat aircraft is supposed to be invincible and that losing even one is a defeat, which is just absurdly unrealistic

With the kind of operational tempo a peer conflict demands, you are going to lose some pilots and machines just from maintenance problems or pilot error without ever even seeing the enemy - I can guarantee you it’s happened on both sides of the Ukraine war. You’ll also have aircraft that aren’t damaged enough to be shot down but get written off as losses upon returning to base, or which will take weeks to repair - and, yeah, inevitably a lot getting shot down, too. The US lost aircraft invading loving Grenada, a microstate the size of a small American city which had no military and didn’t even try to shoot back

Today if one US aircraft were shot down by an enemy it’d be front page news and probably a talking point in the upcoming election, losing 10 in one day would be a Pearl Harbor level national outrage, losing dozens completely unthinkable, yet aircraft losses were just a normal day-to-day part of warfare as recently as Vietnam

http://www.navweaps.com/Weapons/WNUS_8-55_mk12-15.php#ammonote6 posted:

In the late 1960s the "Gunfighter" program at Indian Head Naval Ordnance Station developed Long Range Bombardment Ammunition (LRBA) projectiles. These were Arrow Shells with a body diameter of 4.125" (10.4 cm) and a fin diameter of 5.0" (12.7 cm) which were sized to be fired from 8" (20.3 cm) guns by using a sabot and obturator system. Tests with these in 1968 showed maximum ranges of 72,000 yards (66,000 m). The burster in these shells was PBX-w-106, a castable explosive. Sabot weighed 17.6 lbs. (8.0 kg) and was discarded as the projectile left the muzzle. After a test firing off Okinawa of three inert-loaded shells, USS St. Paul (CA-73) in 1970 conducted a two day bombardment mission against Viet Cong positions at ranges up to 70,000 yards (64,000 m). At the time, St. Paul was the only 8" gunned cruiser still in active service.

mlmp08 posted:

“I wish a country existed that would invest in my good ideas

Stairmaster posted:

wouldn't a bigger shell like 203mm mean a rocket assist would be more effective?

Polikarpov posted:

If the navy was able to push 203mm subcaliber projectiles out to 66km in the 1960s 70km should be easily doable today.

mlmp08 posted:

Now show me that gun being fielded on land by any nation that would consider it a good idea to add to their land forces.

Cerebral Bore posted:

also if the us wanted to move an artillery shell 70 km they'd just send in mlp and tell him that it's actually a set of goalposts

DJJIB-DJDCT posted:

Yes but 203mm howitzer shells are short and fat and 203mm guns, like naval guns, are huge and require something like a fixed platform or railway gun on land.

KomradeX posted:

With how Nazi inspired NATO militaries are I'm shocked they haven't done a tracked "railway" gun

Cpt_Obvious posted:

Megamissen posted:

would having 80km range shells even be a good idea?
considering the strain 40km range shells put on the artillery piece wouldnt it just be better to use rockets or drones

mlmp08 posted:

I’d say it’s goalpost shifting to say “I could not find a ground system for field artillery, but check out this ship in the ocean.”

Ships are famously larger than field artillery units and don’t need to worry about roads and mobility and carry their own ammo stores inside them once deployed.

It would be possible to build some insane mega-gun on land; it’s just a dumb idea. Hence why Hitler’s big dumb railroad gun was not repeated.

DJJIB-DJDCT posted:

Do think I learned about ballistics in a one room schoolhouse or taught myself in my free time?
Or that I paid for my own education in this stuff at all?

A country literally did invest in teaching me, and pays for ideas - about this subject - now. I’m not a travelling salesman, going from town to town in search of tutoring the town’s boys in gunnery.

e: though I’m tickled you’re describing something like sophistry

mlmp08 posted:

I’d say it’s goalpost shifting to say “I could not find a ground system for field artillery, but check out this ship in the ocean.”

mlmp08 posted:

I’d say it’s goalpost shifting to say “I could not find a ground system for field artillery, but check out this ship in the ocean.”

Ships are famously larger than field artillery units and don’t need to worry about roads and mobility and carry their own ammo stores inside them once deployed.

It would be possible to build some insane mega-gun on land; it’s just a dumb idea. Hence why Hitler’s big dumb railroad gun was not repeated.