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Maybe someone here can help. I'm getting all kinds of conflicting information.

Back in the old Crow & Icks days it was often repeated that the M10 TD mounted an old naval 3" gun design. After several years the tide turned and the navy origins of the weapon came into disrepute. No less a figure than Phil Dyer wrote to chide me when I included the 3" gun-navy link in an old AFV News article. And on this forum members brought out the fact that the navy 3" gun and M10 3" gun have different length chambers for different shaped shell casings.

BUT, also on this board someone mentioned an anecdote about M10 TDs after Normandy using clandestinely obtained 3" navy star shells in the direct fire role! And a book I'm now reading on the TD force states outright that the M10 got the 3" gun because the U.S. submarine force was transitioning from its old 3" to 4" deck guns. And I must admit a navy 3" gun I spotted on gate guardian display really really did look like the M10 TD's weapon.

So, what gives? Is the old Crow & Icks era M10 = navy gun idea coming back? Anyone care to venture an opinion about the differencs in chambering?

The usual given lineage for 3" Gun M7, used in the M10 Gun Motor Carriage was from the Army's 3" AAA weapon, which was developed in the 1920's and was in service early into WW2. It was supplanted in the AAA role by the 90mm Gun M1. It might be that the services actually cooperated and developed a gun that could use each others' ammo (that level of cooperation would be surprising). One argument in favor of this is that AAA was under the auspices of the Coast Artillery who were more used to dealing with naval-type weapons and ammo.

I certainly can't claim expertise, but I DO know that the Navy had several 3" caliber weapons in use by WW1. The Army's 3" AA gun MIGHT have been evelpoed with or from the Navy's gun. There were numerous variation on the Navy 3" gun, see;

www.navweaps.com/Weapo...k10-22.htm

This is part of a nice site on naval ordnance thru the years.

As to the differing chambers, I wonder if the old 3" naval (AAA?) chamber might have been rebored for shorter bottle-shaped rounds for easier tank stowage. [Ooops -edited. It seems from the message the naval gun had a WIDER shell casing, not narrower. So much for reboring].

- mike_Duplessis

Maybe someone here can help. I'm getting all kinds of conflicting information.

Back in the old Crow & Icks days it was often repeated that the M10 TD mounted an old naval 3" gun design. After several years the tide turned and the navy origins of the weapon came into disrepute. No less a figure than Phil Dyer wrote to chide me when I included the 3" gun-navy link in an old AFV News article. And on this forum members brought out the fact that the navy 3" gun and M10 3" gun have different length chambers for different shaped shell casings.

BUT, also on this board someone mentioned an anecdote about M10 TDs after Normandy using clandestinely obtained 3" navy star shells in the direct fire role! And a book I'm now reading on the TD force states outright that the M10 got the 3" gun because the U.S. submarine force was transitioning from its old 3" to 4" deck guns. And I must admit a navy 3" gun I spotted on gate guardian display really really did look like the M10 TD's weapon.

So, what gives? Is the old Crow & Icks era M10 = navy gun idea coming back? Anyone care to venture an opinion about the differencs in chambering?

Well, according to Tony Williams site, the 76.2 x 585R cartridge case with a 103mm rim diameter was used in:

- 3" M1902 coast gun,
- 3" M1918, M1, M3 AA guns
- 3" M5 + M7 AT guns
- 3" M6 tank gun

US 76.2mm L/50 naval guns used a 76.2 x 585 to 594R cartridge case with a 111mm rim diameter.

It would seem that the 3" M1902 Coastal Gun fired a 15 pound round, which may be significant because in Hogg (ed): "The American Arsenal" it says about the M1918 AA gun that the design was based on a 3" (15 pdr.) Gun M1898 which seems to be another piece of coastal artillery.
The naval guns, on the other hand, seems to have fired a slightly lighter projectile of about 13 pounds. There also seems to be differences in the rifling, the M7 guns and its predecessors having one twist in 40 calibers, the naval guns having a 1 in 25.
So the naval gun and the anti-tank gun are simply not the same, which should remove any possibility that the M10s were ever armed with ex-submarine guns.

As for the use of navy star shells, the reason might be that the navy also used anti-aircraft guns from which the M7 gun originated. Or it may be that hey obtained the 3" shells and paired them with the proper cartridge.
I dont think the cartridge size would allow the use of the naval cartridge in the M7 anti-tank gun and vice versa.

If the M7 anti-tank gun has a naval background, it would be if the M1898/M1902 coastal guns originated in the 3" naval gun, which seems to have been made at the same time. But one may then question what "design" actually means, as both the cartridge and the gun was different between the two.

What book on TDs are you currently reading - perhaps it just got the info off the old Icks & Crow?

Claus B

To help stir the pot, here's a sharp photo of a U.S. 3" AA gun breech and its round around 1941.

The book on TDs that I'm reading is "The Tank Killers" by Yeide. It was published in '05 and is filled with oherwise authoritative sounding detail. I tend to believe a book until I stub my toe on an obviously wrong factoid - so far so good with this book.

Don't let that take away from Mr. Yeide's book. He just wasn't into the minutae of where the gun came from. 3" is often a caliber associated with the Navy (at least in US terms), so the connection is easily drawn.

I looked at Yeide's book last night

"A converted 3-inch (76mm) converted antiaircraft gun was mounted in an open top turret... A large number of 3-inch guns were available because they were being replaced on submarines by 5-inch models and in antiaircraft units with 90mm guns. "

It is footnoted "Telephone interview with John Hudson, May 2002. Gill, 17."

John Hudson is identified elsewhere as a Tank Destroyer Platoon Leader.

Gill is further identified as

Lonnie Gill, Tank Destroyer Forces, WWII (Paducah, Kentucky: Turner Publishing Company, 1992)


According to Norman Friedman in U.S. Submarines Through 1945: An Illustrated Design History The replacement of 3" guns with larger ones was not approved until June of 1942 and even then it was only 'afterthe fact' with 4" guns coming off decommisioned S-boats (Those guns were WWI or 1920s vintage) The 5" guns came even later and also were initially guns removed from other ships 5"/51 cal guns from the secondary batteries removed from Battleships and 5"/25 cal old AA guns that had been replaced in surface ships with 5"/38 guns were mounted. They were desired not for AA use but for antisurface use when Subs started doing more surface action late in the war

For thos not familiar with Friedman. I think of his 'Illustrated Design History' series in the same catagory as Hunnicutt

Mr Yeide lives in the Washington D.C. area according to his bio. I've thought about contacting him to try and get my copies of his books signed. Maybe I'll see if he still goes along with the ex-naval gun idea.

I'll put in a plug for his 'Steel Victory' book about the independent tank battalions in Europe. I think it covers what had been a large gap in the story of armor units in WWII

Hi all,

It may have been on another topic altogether, but I recall a similar discussion on the old board. My memory is of a discussion regarding the 75mm or 76mm ammunition for the M4 tank (maybe the Firefly version?). The expert consensus was that the tankers took the projectiles from the Navy and put them into cartridge cases that fit the tank's gun.

Perhaps a similar situation resulted in star shells for the 3" TD guns?

C

- C_Sherman

Hi all,

It may have been on another topic altogether, but I recall a similar discussion on the old board. My memory is of a discussion regarding the 75mm or 76mm ammunition for the M4 tank (maybe the Firefly version?). The expert consensus was that the tankers took the projectiles from the Navy and put them into cartridge cases that fit the tank's gun.

Perhaps a similar situation resulted in star shells for the 3" TD guns?

C

I remember a discussion a while back about the Marines on one of the Pacific Islands running into a shortage of either M4 75mm ammo or 75mm Pack Howitzer ammo and repackaging projectiles and charges from one into brass form the other. I think Oscar Gilbert or Ken Estes was the source

I've had a problem all along with the "converted artillery/AA/naval weapon" idea. The gun cradle for the 3" gun on the M10 has twin recoil cylinders mounded either side of the barrel. You can see from the AA gun photo above that that recoil was a single attachment to the top of the breech! It looks to me like it might use the same ammo casings and maybe the same 3" barrel (not including the breech) but everthing else looks to be be new. That's like saying the howitzer on the M8 HMC was a 'converted' 75mm pack howitzer gun. You'd be hard pressed to come up with a common parts list for those two weapons.

I guess it all depends on what one means by 'converted'. I'm reminded of the story of grandpa's trusty hammer. Grandpa's hammer was indestructable, used continuously for 50 years without a problem, had to replace the handle three times and the head twice but it kept on going.

I'm not in Ordnance, but it was my impression that the GUN is the barrel and breech, while the MOUNT includes the recoil and training parts. I can't speak for the breech, but there is reference to the 3" gun M7 using the barrel of the 3" AA gun. A similar process was used to mate the barrel of the 3" AA gun to the breech and mount of the 105mm howitzer to create the towed 3" AT gun.

By the way, if I remember my TM (it's been a while since I read it) the barrel and breech of the 75mm howitzer in the M8 Howitzer Motor Carriage WAS from the pack howitzer. There were converted barrels with a key added to fit the mount and new production barrels with the key integral (so I suppose those last were NOT converted guns - so we're BOTH right). The manual mentioned the parts differences.