USN Fire Support Gun Proposals

[Kat Tsun]

Feed system for the Mark 65/66 sounds like something of a nightmare:

The advantage of the Carronade on paper is saturation bombardment and weight, I think. 40RPM for the 5" Mark 42, 48RPM for the Mark 65 (and I'll assume 96 for the Mark 66 since it's a double mount Mk 65). Carronade had eight launchers firing at 30 rounds per minute each. Payload-wise the rockets came in a few variations based on range and packed anywhere between 12lbs TNT to 1.7lbs Explosive D with ranges of 2500 to 10,000 yards and HC, Common and GP warheads. But the advantage is you can fit a lot more rocket launchers on a shallow-draft 1500 ton hull than 5" guns of whatever kind, and the Carronade/LSM(R)s were intended to support amphibious landings at closer range.

9 kilometers is not useful for fire support for an amphibious landing outside of Incheon or something. Carronade would have been excellent there.

The problem is that anti-landing forces had shifted from being a beach defense to a more inland, mobile defense by 1958 or so. The BTR-60 really helped this, as did the D-30 howitzer (15 km range), both of which showed up at the tail end of the 1950s. They are what changed the game for Soviet mobile troops. This is why the U.S. Navy wanted a 25 kilometer range gun initially (Mark 65/66), before shifting to a 30 kilometer range gun to duel with D-30 batteries, in the MCLWG.

Mark 105s wouldn't be useful because they wouldn't be able to get close enough to the beach to conduct counter-battery.

On the idea of big guns on small ships, there's also the outdated but entertaining example of the converted Lord Clive-class monitors used for shore bombardment by the Royal Navy in WWI. Their basic armament was a two-gun 12"/35 Mark VIII turret recycled from the Majestic-class battleships. Nine total were built, but the really fun ones are HMS Lord Clive and HMS General Wolfe (a third conversion was underway but cancelled at the end of the war). They each got a single BL 18"/40 Mark I off the HMS Furious in a semi-fixed deck mount with an open-backed gun shield. Ugly as sin but surprisingly effective, Wolfe took the longest combat shot in Royal Navy history bombarding a rail bridge at Snaaskerke, Belgium from 36,000 yards.

View attachment 756121

Some proposals were functionally this, it's been a while since I looked at the LFS chapter in Amphibious Ships and Landing Craft, but landing operations in the North Sea and near Vladivostok preclude offensive riverine operations for the most part.

You're doing a circuit run 5-10 kilometers off shore instead because any closer and you might run into naval mines or just run aground.

 

[Tzoli]

The first Soviet anti-ship missile was deployed nearly half a decade after Carronade entered service. I think the real question is why did Carronade exist when Mark 42 was right there. Besides having double the range, the Mark 42 had far more useful natures of ammunition, it could also fit on a destroyer.

Anyway they were supposed to be replaced by the near identical 48 rounds/minute Mark 65 or Mark 66 but both of them died.



I think the 5" would be for the illumination and smoke rounds. MCLWG and 16-in. were high capacity and nuclear only. They'd probably have got a Phalanx mount somewhere and maybe a BPDMS installation if they'd been built for self-defense.

There are no evidence nor logic behind your claim of both 8" and 12" and 16" MCLWG designs being Nuclear only. The 8" would be the new standard naval gun and the 12" and 16" guns would be bombardment weapons to be used for not only Soviet targets but against any beach. See the first Gulf War. Even during the Vietnamese War no such shells were used.

 

[yeetmahboi]

behind your claim of both 8" and 12" and 16" MCLWG designs being Nuclear only

Kitsun didn't said nuclear only, very clearly he claimed

high capacity and nuclear only

High capacity could be either unitary or dispenser.

 

[Dilandu]

9 kilometers is not useful for fire support for an amphibious landing outside of Incheon or something. Carronade would have been excellent there.

Well, the earlier rocket ships - the wartime-build LSM(R) - were used at Incheon. They weren't much different from Carronade, except they were build on LSM hulls and used older Mk-102 launchers with slower reload (still, the "slower" was relative - the Mk-102 fired each 4 seconds, Mk-105 each 2)

 

[TomS]

Kitsun didn't said nuclear only, very clearly he claimed

High capacity could be either unitary or dispenser.

High Capacity (HC) refers specifically to a (relatively) thin wall high explosive round. The HC round for the 8-inch MCLWG would have had a roughly 8% bursting charge. A cargo shell with submunitions would probably have about twice that weight in payload, but they didn't really exist when MCLWG was being designed.

There was also an 8-inch Paveway laser-guided round, but details on that are scarce.

 

[yeetmahboi]

High Capacity (HC) refers specifically to a (relatively) thin wall high explosive round. The HC round for the 8-inch MCLWG would have had a roughly 8% bursting charge. A cargo shell with submunitions would probably have about twice that weight in payload, but they didn't really exist when MCLWG was being designed.

There was also an 8-inch Paveway laser-guided round, but details on that are scarce.

I wasn't sure if HC is a definite HE, going by the AGS-Lite topic, but thanks for the clarification.

 

[TomS]

I wasn't sure if HC is a definite HE, going by the AGS-Lite topic, but thanks for the clarification.

USN terminology gets confusing. At some point, they switched from HC to HE for basically similar 5-inch projectiles.

 

[Firefinder]

The HC and HE Terms was very much from the old Army Navy having completely different...

EVERYTHING days back before the turn of the LAST century.

The Army and Navy may have had the same size guns, say a 3 pounder breechloader, but the ammo was outright NOT INTERCHANGABLE. As in put an army shell in a navy gun will get you a bomb due to minote differences in the bore. This was extremely dangerous with hollow out shells to carry high explosive. So the different terms was use to denote who shell it was.

That change bit before WW1 thanks to better manufacturing and the realization of logicist of modern war needs but the differences continued thanks to TRADITION til both branches lost their factory bases.

 

[Kat Tsun]

Well, the earlier rocket ships - the wartime-build LSM(R) - were used at Incheon. They weren't much different from Carronade, except they were build on LSM hulls and used older Mk-102 launchers with slower reload (still, the "slower" was relative - the Mk-102 fired each 4 seconds, Mk-105 each 2)

Yeah the Mark 105 was basically a PI Mark 102 but unfortunately it showed up at the same time as D-30. Hence the 25 km range Mark 66.

There are no evidence nor logic behind your claim of both 8" and 12" and 16" MCLWG designs being Nuclear only. The 8" would be the new standard naval gun and the 12" and 16" guns would be bombardment weapons to be used for not only Soviet targets but against any beach. See the first Gulf War. Even during the Vietnamese War no such shells were used.

The 16"/50 guns would have been the Mark 7 rifles used in the Iowas. Their natures of ammunition would be high capacity and nuclear. The 175-mm was never developed far enough to know what natures of ammunition it would possess. MCLWG as built had HC and CLGP. Nuclear wouldn't be off the table, especially if they were using 8" Army projectiles, but I think the higher MVs scuppered that. Maybe.

 

[Dilandu]

it showed up at the same time as D-30. Hence the 25 km range Mark 66.

? What system you refers to?

 

[Kat Tsun]

? What system you refers to?

This was the replacement for the Mk 105 rocket launcher. It had a 25 kilometer effective firing range, which is the same as the Mark 45 5"/54 mount and a bit further than a Mark 42 5"/54, but a much faster rate of fire than either with a combined 96 rounds per minute. It would have been fitted to some sort of fire support ship in the late 1960's, but when the Mark 65 DP gun (the single mount) was canceled in favor of the Mark 45, the Mark 66 died with it.

Think of it as a Mark 45's automatic housing mated to a Mark 42's high rate of fire. IIRC lack of reliability and weight is what killed it. The Mark 42's ended up getting downrated anyway after Vietnam because it turned out their 40-ish rounds per minute rate of fire was literally shaking them apart. To get the Mark 65 both automated and high ROF, BuOrd decided an even more complicated reloading system was necessary, and then took a look at it versus the Mark 45, and the Mark 42's performance on Vietnam gun lines, and gave up.

RIP ultimate bombardment mount.

 

[Dilandu]

This was the replacement for the Mk 105 rocket launcher. It had a 25 kilometer effective firing range, which is the same as the Mark 45 5"/54 mount and a bit further than a Mark 42 5"/54, but a much faster rate of fire than either with a combined 96 rounds per minute. It would have been fitted to some sort of fire support ship in the late 1960's, but when the Mark 65 DP gun (the single mount) was canceled in favor of the Mark 45, the Mark 66 died with it.

Ah! Now I understood, thank you!

 

[Dilandu]

This was the replacement for the Mk 105 rocket launcher.

Wonder why they didn't try to develope the new compatible rocket for existing launchers. The progress in rocket engines in 1950-1960 would likely allow spin-stabilized rocket to have twice as much range (modern fuel and dual-thrust motor, for example) as WW2 one in the same size and weight.

 

[Kat Tsun]

Wonder why they didn't try to develope the new compatible rocket for existing launchers. The progress in rocket engines in 1950-1960 would likely allow spin-stabilized rocket to have twice as much range (modern fuel and dual-thrust motor, for example) as WW2 one in the same size and weight.

This is basically what ABRS was but the fashion of the time (~1960-1973) was something more like the Lance ballistic missile.

 

[Scott Kenny]

The 16"/50 guns would have been the Mark 7 rifles used in the Iowas. Their natures of ammunition would be high capacity and nuclear.

Agreed, no reason for the 2700lb AP shells, just 1900lb HE or nuke.

The 175-mm was never developed far enough to know what natures of ammunition it would possess.

Wasn't the 175mm supposed to use Army shells? So it'd have the same assortment as the M107. A couple different HE, maybe an extended range type with either base bleed or rocket assist, but it doesn't look like the US ever made 175mm nuclear artillery shells.

MCLWG as built had HC and CLGP. Nuclear wouldn't be off the table, especially if they were using 8" Army projectiles, but I think the higher MVs scuppered that. Maybe.

As I understand it, what would matter would be acceleration forces at firing. As long as the MCLWG had the same initial acceleration, nuclear shells would be possible.

 

[Firefinder]

The 175-mm was never developed far enough to know what natures of ammunition it would possess.

Wasn't the 175mm supposed to use Army shells? So it'd have the same assortment as the M107. A couple different HE, maybe an extended range type with either base bleed or rocket assist, but it doesn't look like the US ever made 175mm nuclear artillery shells.

Yes the 175mm was to use the same gun as found on the M107 SPG the Army was using in Nam. That had mainly a HE and a Illumation round in US service with a Range of around 40km, which was bout 2km more then the16s ever got.

Israeli later got a a shell that boosted the 175mm range out to 50km which they used to great effect shelling SAM sites, enough that they keep it in reserve to this day, and thats 12km more.

Neither use Basebleed or RAP to reach that range, that was all raw ballistics from the powder charge. So you can easily reach out to 60 70km using the Israeli shell with basebleed, tickle 100 with rap, which I recall them looking into that in the 90s.

The navy 175mm gun WAS to be a navalize version of the Army's mounted to what became the Mk71 turret assembly. With the expectation of using Army shells cause the entire deal was meant to be a CHEAP weapon to replace the Heavy Cruisers. Which with the gunfighter shells could reach out to 70km from their 8 inchers with USS Saint Paul proving that in Nam and the MK71 turret was design with those in mind. Thats why the Armor for it was load in 3 shot clips deals, it was design to fit either a shell case combo in all three, or an Arrow shell in one and a powder case in another with the third empty for incase of needing to unload the mount.

The MK71 got change to the 8 inch size when the Army stated they were dropping the 175mm around 1972, with 8 inch being chosen cause the navy had like... Multiple TONS worth of ammo and barrels from the retired Heavy Cruisers still with that still being consider good til the mid 1990s early 2000s since they was still making that up to 1960 something unlike the BB gear which end in the 40s. And those was still side compatible with Army shells since the Navy outright stole the Army W33 for use on the CAs as seen by the USS Salem who has the same mods as the Iowa's do to hold Nuke Shells and all the paper on it in that museum.

 

[Dilandu]

Wonder why 11-inch wasn't considered. There was a supply of 11-inch shells - both HE and nuclear from army's M65 cannons - and production could be restarted at least in theory.

 

[DWG]

The Army and Navy may have had the same size guns, say a 3 pounder breechloader, but the ammo was outright NOT INTERCHANGABLE.

Possibly a poor example given pretty much all 3Pdrs were Hotchkiss or Maxim-Nordenfeldt with common ammunition across not just Army/Navy, but internationally.

 

[A Tentative Fleet Plan]

Wonder why they didn't try to develope the new compatible rocket for existing launchers. The progress in rocket engines in 1950-1960 would likely allow spin-stabilized rocket to have twice as much range (modern fuel and dual-thrust motor, for example) as WW2 one in the same size and weight.

They did look at developing 5-inch rockets with ranges of up to 20,000 yards in the late 1960s (existing rockets went out to 10,000 yards).

 

[Dilandu]

They did look at developing 5-inch rockets with ranges of up to 20,000 yards in the late 1960s (existing rockets went out to 10,000 yards).

But nothing came ouf ot it, I suppose?

 

[A Tentative Fleet Plan]

Hm, so was this program related to the Inshore Fire Support Ship/USS Carronade? One-off commissioned in 1955 as a replacement for the rocket launcher LSM(R) conversions used in WWII, Korea and Vietnam, always wondered why that concept was never pursued any further (Warsaw Pact anti-ship missiles, I guess). 1500 tons displacement, with a 5"/38 single mount and eight Mk 105 double-barreled rocket launchers firing 5" spin-stabilized bombardment rockets at the ridiculous rate of thirty per minute per launcher. Or was this thread's FSS another entry in the neverending argument about naval gunfire support not related to the rocket-slingers?

This programs were Vietnam-era, primarily to replace Second World War era Battleships and Cruisers, particularly for long range counter-battery (hence why long range missiles like ZBGM-59 Taurus or Lance were considered). They were

Carronade was a late-1940s design, built as part of the early 1950s panic mobilisation for the Third World War that never came, primarily for close-range fire support immediately prior to landing, intended originally as a 20-knot design (a requirement which was dropped as it was incompatible with that required for shallow draft), and designed to built mass-produced (no deck camber or air conditioning).

 

[A Tentative Fleet Plan]

But nothing came ouf ot it, I suppose?

Friedman doesn't mention anything more about development,just that they were under consideration in the late 60s.

Rockets were essentially viewed as incompatible with long-range guns, adding significantly to size and cost, they ended up being dropped from the Landing Fire Support ship design circa 1969, and that rockets should be put on separate Inshore Fire Support Ships (there is a brief mention of a 1968 design of such as vessel with a hull based upon the LST-1179).

 

[Kat Tsun]

Agreed, no reason for the 2700lb AP shells, just 1900lb HE or nuke.

DON had a bunch of 'em so if we had to crack submarine pens or underwater munition depots they could work I guess.

Wasn't the 175mm supposed to use Army shells?

I think the entire point of MCLWG was to share Army and Navy projectiles for long range counter-battery gunnery.

So it'd have the same assortment as the M107. A couple different HE, maybe an extended range type with either base bleed or rocket assist, but it doesn't look like the US ever made 175mm nuclear artillery shells.

The Navy might demand it but even the KT rounds were on the way out by the time the LFS was being considered. Preference dictated delivery of nukes by guided missile like Lance or Lacrosse. Naval Lacrosse would've been badass though.

As I understand it, what would matter would be acceleration forces at firing. As long as the MCLWG had the same initial acceleration, nuclear shells would be possible.

No, barrel length also matters. Army shells had copper drive banding and high MVs destroy those. The banding on the bottom of the W33 and W79 carrier shells is copper. Depending on the length of the bore and the velocity at exit, that banding could disappear, which would cause balloting and damage the tube and projectile.

This is exactly how ERCA, another historically high MV gun, failed. That said, at "only" 50,000 psi, I'm not sure Mark 71 qualifies as that level of risk. It's definitely more demanding of a copper band, but it's also only 800-850 m/s, which should be doable just fine without issue. I don't know the specifics of Mark 71's projectiles but I doubt the Navy was setting up a wholly separate supply chain. OTOH, perhaps the shift from 175-mm to 203-mm was driven by driving band issues.

We will never really know because it never entered service but I think it could be done in a pinch. The Army projectiles won't like it but they probably won't kill themselves coming out the bore.

 

[Kat Tsun]

Wonder why 11-inch wasn't considered. There was a supply of 11-inch shells - both HE and nuclear from army's M65 cannons - and production could be restarted at least in theory.

It was, but only using existing shells, and fired in sabots from the Mark 7 rifles. That was part of Gunfighter.

The LFS battleship gun monitor probably would've had some Gunfighter-type projectiles eventually.

 

[TomS]

Friedman doesn't mention anything more about development,just that they were under consideration in the late 60s.

Rockets were essentially viewed as incompatible with long-range guns, adding significantly to size and cost, they ended up being dropped from the Landing Fire Support ship design circa 1969, and that rockets should be put on separate Inshore Fire Support Ships (there is a brief mention of a 1968 design of such as vessel with a hull based upon the LST-1179).

If you are standing off at gun ranges (in that era) the rockets are dead weight. If you are in rocket range, the extra range of big guns is wasted.

On Carronade, I think the 5-in/38 was intended primarily for illumination or smoke rounds with HE for point targets that rockets were unsuited for, given their general inaccuracy in the era.

 

[Dilandu]

If you are standing off at gun ranges (in that era) the rockets are dead weight. If you are in rocket range, the extra range of big guns is wasted.

Well, during Vietnam War the rocket support ships often went in close combat - especially on rivers - but I agree, that it's not exactly their intended role and in conflict with more comparable enemy it would be too risky to try it.

Still, I'm not sure about rockets being a dead weight. Assuming that rocket technology of 1960s could provide the 5-inch rocket with the 20.000 meters range (i.e. twice the WW2 era rocket range) - which seems to be perfectly possible, considering the improvements in both engine designs and rocket fuel! - they would reach basically 2/3 as far as Mk-71 could.

 

[Kat Tsun]

Well, during Vietnam War the rocket support ships often went in close combat - especially on rivers - but I agree, that it's not exactly their intended role and in conflict with more comparable enemy it would be too risky to try it.

Still, I'm not sure about rockets being a dead weight. Assuming that rocket technology of 1960s could provide the 5-inch rocket with the 20.000 meters range (i.e. twice the WW2 era rocket range) - which seems to be perfectly possible, considering the improvements in both engine designs and rocket fuel! - they would reach basically 2/3 as far as Mk-71 could.

Yeah they could probably make a rocket the size of a Mk 105's projectile go like 15-20 kilometers and present a credible threat to howitzers arrayed against an assault beach. Unfortunately, at this time the most advanced American rocket launcher looked like this:



DOD was having a moment and it percolated down to the DON, DA, and DAF. Perhaps something more akin to a Grad would've been possible, if they had the capacity to think of it, but the Navy considered rockets too inaccurate and so decided they needed a deck gun that shot 100 rounds/minute.

The Marines just thought rockets could be more made accurate with barrels, because after all, guns have barrels and guns are accurate!

 

[Dilandu]

Unfortunately at this time the most advanced American rocket launcher looked like this:

Hm, frankly I think the Mk-105 was more advanced; it was fully automatic and central-controlled.

The Marines just thought rockets could be more made accurate with barrels, because after all, guns have barrels and guns are accurate!

Partially true, but the reason is differen - the longer rail helped to stabilize the rocket while it was accelerating and thus improve accuracy. But Navy didn't like long rail launchers because they took too much space; the zero-length launch tube was preferred solution.

 

[Kat Tsun]

Hm, frankly I think the Mk-105 was more advanced; it was fully automatic and central-controlled.

It was the newest is what I meant, and thus represented the state of the art, even if it had regressed.

Partially true, but the reason is differen - the longer rail helped to stabilize the rocket while it was accelerating and thus improve accuracy. But Navy didn't like long rail launchers because they took too much space; the zero-length launch tube was preferred solution.

I think the Marines were just silly and didn't consider the practical benefit of a rocket launcher was in immediate suppression capacity.

"There's something out there, and it ain't no man...it's a camouflaged DFP with light overhead cover," or something.

 

[Dilandu]

I think the Marines were just silly and didn't consider the practical benefit of a rocket launcher was in immediate suppression capacity.

Considering that marines liked exactly that in rockets, I highly doubt that. Marines always liked rocket artillery - exactly because it could provide suppression fire in great volume. On the contrary, Army didn't like rocket artillery, considering it inaccurate and too wasteful on ammo. They argued that the main goal of artillery is hit the target, not territory (it's what air force for) and in case area strike is needed, the nuclear shell would work better.

 

[Kat Tsun]

Considering that marines liked exactly that in rockets, I highly doubt that. Marines always liked rocket artillery - exactly because it could provide suppression fire in great volume. On the contrary, Army didn't like rocket artillery, considering it inaccurate and too wasteful on ammo. They argued that the main goal of artillery is hit the target, not territory (it's what air force for) and in case area strike is needed, the nuclear shell would work better.

The Marines were following the Army in the 1960s in most respects. The areas they weren't were related to small unit tactics at section level.

XM70 was an attempt to throw as large a payload fraction as far and as accurate as possible, and with zero backblast, so it could be crewed like a howitzer. It didn't work very well because they never built more than half a dozen or something. The idea of rocket launchers as saturation weapons useful for suppression, or wide area attack, wasn't seen as important until the 1970s and the Yom Kippur War.

They were just looking at the biggest, lightest bombs they could make to drop squarely through the roof of a log bunker.

Most of this stems from the Pentomic Divisions and their emphasis on see-shoot-kill using tactical nukes. The Army realized this was infeasible for cost constraints (among other issues) so it tried to replicate Pentomic's battlefield effects with non-nuclear ordnance i.e. precision guided munitions.

XM70E2 and the highly accurate artillery pieces like M107 were sort of the first attempt at this.

 

[A Tentative Fleet Plan]

On Carronade, I think the 5-in/38 was intended primarily for illumination or smoke rounds with HE for point targets that rockets were unsuited for, given their general inaccuracy in the era.

Also for suppressing enemy coastal batteries in the way in to rocket firing range, according to Friedman.

 

[Firefinder]

No, barrel length also matters. Army shells had copper drive banding and high MVs destroy those. The banding on the bottom of the W33 and W79 carrier shells is copper. Depending on the length of the bore and the velocity at exit, that banding could disappear, which would cause balloting and damage the tube and projectile.

This is exactly how ERCA, another historically high MV gun, failed. That said, at "only" 50,000 psi, I'm not sure Mark 71 qualifies as that level of risk. It's definitely more demanding of a copper band, but it's also only 800-850 m/s, which should be doable just fine without issue. I don't know the specifics of Mark 71's projectiles but I doubt the Navy was setting up a wholly separate supply chain. OTOH, perhaps the shift from 175-mm to 203-mm was driven by driving band issues.

We will never really know because it never entered service but I think it could be done in a pinch. The Army projectiles won't like it but they probably won't kill themselves coming out the bore.

This is not the issue you making it out to be. You literally just wrong here boss.

The Standard Navy Shell at the Time used copper bands as well, they only recently went away from that. The Pre WW2 era Mark 12s to 16s could hit 900 MPS with supercharge loads, did so regularly, and they did just fine for over 30 years of service using copper band projectiles of far heavier weight.

Difference here is that the Navy, and Army for that matter, was more willing to just...

Change the Barrels out after 700 or so shots.

The ERCA for comparison was averaging 950 full supercharge shot. The 155/39 and 52 average over 2k full power shots which the later 203mm did, while the 175mm was design for 1500, got derated down to 500 due to manufacturing fails which got fix to put it back up to 1500.

That was a four hour job on the 9 gun Cruisers, so likely was a 2 hour job for a Destroyer size one since it was a 45 minute job on a M110.
Like unlike now with the short of EVERYTHING especially bodies, doing barrel change was a common maintance job on par with changing the oil. Was just something you did semi regularly. The Change from the 175 to 203 all had to do with the Army dropping the 175mm and that had to do with the manufacturing, accuracy, poor rep, and just the pain in the ass length of the 175mm compare to BaseBleed/RAP the 203s which got the same range.

And the US Army 8 inch shells WERE design to be interchangeable with the Navy cause of a Congress mandate back around 1900 which was still in effect and since it was a high level rare gun it was honestly cheaper for the Army to siphon off from the Navy effects. We have docs proving that as late as Vietnam with the US Heavy Cruisers and Army fire bases using helicopters to swap ammo around as need from their magazines.

 

[Kat Tsun]

The ERCA for comparison was averaging 950 full supercharge shot.

That's muzzle velocity. Drop the zero and halve it for barrel life. ERCA ate tubes because of balloting from in-bore disintegration of the copper driving band, among other things. XM282 is really funny, because Benet and Picatinny keep forgetting it eats driving bands pretty much every time they shoot it, and ERCA was the second time this has happened.

The rest of this is no different to what I said, except I'm not sure if the Navy would actually use Army projectile bodies rather than it being impossible. Mark 71 would certainly benefit from a longer length:diameter shell body and the CLGP was unique to the Navy.

Considering the original question was about whether or not Mark 71 would use nuclear shells, I was suggesting it might use the AFAP rounds.

 

[Firefinder]

That's muzzle velocity. Drop the zero and halve it for barrel life. ERCA ate tubes because of balloting from in-bore disintegration of the copper driving band, among other things. XM282 is really funny, because Benet and Picatinny keep forgetting it eats driving bands pretty much every time they shoot it, and ERCA was the second time this has happened.

No that was the barrel life, the ERCA was listed as having 950 shots of barrel life with supercharge.

Its Velocity was over 1000 meters a second. You getting them mixed up. The muzzle velocity for the 155/52 with charge 8 on say the PZH2000 is around 1085 meters a second.

That 950 count is an order less than the standard guns amount of over three times that on the low end.

The rest of this is no different to what I said, except I'm not sure if the Navy would actually use Army projectile bodies rather than it being impossible. Mark 71 would certainly benefit from a longer length:diameter shell body and the CLGP was unique to the Navy.

The Army also tested an arrow shell in the 1980s and dropped it due to accuracy issues from the shorter length barrels, which was roughly L28 irc.

As is the US army L28s 203mm did outreach the navies 203mm L55 by bout 3km, with rap the M110 got 30km to 34 with the longer L30 barrel compare to the MK16/MK71 27km. Thats due to the army keeping its RD up on the 8inch projectiles after the 1950s after the navy stop on them for missiles. Which is why the USS Salem has the gear to USE the W33 8inch AFAP since the navy was not bout to budget fight to make their own.

 

[Kat Tsun]

No that was the barrel life, the ERCA was listed as having 950 shots of barrel life with supercharge.

It was wishful thinking...

Its Velocity was over 1000 meters a second. You getting them mixed up. The muzzle velocity for the 155/52 with charge 8 on say the PZH2000 is around 1085 meters a second.

Its velocity killed it, but for the same reason why ERCA died, Pzh 2000 is able to fire at that velocity consistently and reliably.

That 950 count is an order less than the standard guns amount of over three times that on the low end.

Yet it never achieved even that.

Anyway the reason I say that MCLWG might've ran into issues is because the 8"/55 was supposed to be produced as a 8"/60 and have a slightly higher MV than the 800-850 m/s that was tested. I'm not sure if it would require a new assembly line for Navy projectiles or not. Given how many issues they ran into, I suspect that Dahlgren didn't know either, and would've figured it out as it happened.

This is genuinely an unknowable question because the production Mark 71 MCLWG was never built, but as long as it stayed under ~900 m/s consistently, it would have avoided the drive band problem.

OTOH the DIB has the institutional memory of a goldfish with Alzheimer's. The whole "copper bands hate 900 m/s and up" issue is like cicada blooms but with more swearing: it happens every 15-20 years at Dahlgren or Benet.

The Army also tested an arrow shell in the 1980s and dropped it due to accuracy issues from the shorter length barrels, which was roughly L28 irc.

The Gunfighter shells were badass.

As is the US army L28s 203mm did outreach the navies 203mm L55 by bout 3km, with rap the M110 got 30km to 34 with the longer L30 barrel compare to the MK16/MK71 27km. Thats due to the army keeping its RD up on the 8inch projectiles after the 1950s after the navy stop on them for missiles. Which is why the USS Salem has the gear to USE the W33 8inch AFAP since the navy was not bout to budget fight to make their own.

RAPs are garbage but Mark 71 would probably be able to counter-battery 2S7s with them.

 

[Scott Kenny]

My current giggle is the idea of a long 155mm shell in a sabot in an 8" gun barrel.

Composite sabot petals, technology taken from 120mm tank ammo.
Long 155mm shell probably a rocket boosted GPS-guided unit, just not the LRLAP round.
Easily pushing 1000m/s MV, if not 1200m/s.