Aces High Bulletin Board

General Forums => Aircraft and Vehicles => Topic started by: frank3 on January 20, 2003, 07:42:18 AM

Title: 75mm gun!
Post by: frank3 on January 20, 2003, 07:42:18 AM
can you believe it? (it only had 20 rounds) it's in the nose for those who can't see it :D
Title: 75mm gun!
Post by: Tony Williams on January 20, 2003, 02:01:27 PM
That was the 75mm M10, which used the same ammo as the earlier M4 and M5 (and the Sherman tank) but fired automatically at around 30 rpm. Neither it nor the plane (a Beech XA-38 Grizzly) ever entered service.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and Discussion forum (http://forums.delphiforums.com/autogun/messages/)
Title: 75mm gun!
Post by: whgates3 on January 21, 2003, 12:51:36 AM
...not that 75mm A/C guns were not active in WWII...B-25 & Hs-129 both carried them into combat...
(http://www.luftwaffepics.com/LCBW/Hs129-75mm-6.jpg) (http://www.warbirdsresourcegroup.org/URG/images/b25-014.jpg)
Title: 75mm gun!
Post by: frank3 on January 21, 2003, 04:48:19 AM
some B-25/26 versions also had a 75mm cannon in the nose,
sure would be usefull for carrier attacks
Title: 75mm gun!
Post by: gofaster on January 21, 2003, 08:45:55 AM
Quote
Originally posted by frank3
some B-25/26 versions also had a 75mm cannon in the nose,
sure would be usefull for carrier attacks


Correct.  They used them to attack Japanese freighters in the Pacific.  There's a gun camera film segment that shows such an attack.  You see a bunch of .50 cal tracer rounds ricocheting around and then two giant plumes of water bracket the freighter.  It may have been in "Midway" or some other piece of mainstream film because I remember seeing it fairly regularly when going through my movie collection.

Because of its size, the cannon was installed in the bomb bay, so no bombs could be carried internally.
Title: 75mm gun!
Post by: Spritle on January 21, 2003, 02:17:39 PM
Wrong!

The B-25H had the 75mm mounted entirely under the cockpit.  It still had a fully functioning bomb bay with bombs no less.

Also it was a fairly low velocity weapon and while it might have worked well against Japanese supply ships it would hardly scratch the paint on a carrier.

Spritle
Title: 75mm gun!
Post by: Shiva on January 21, 2003, 02:36:49 PM
Quote
Originally posted by Spritle
Also it was a fairly low velocity weapon and while it might have worked well against Japanese supply ships it would hardly scratch the paint on a carrier.


Assuming that you'd get close enough in through the ack to be able to do it, a decent pilot should be able to lob shots into the hangar deck through any open elevators, and if they have fueled and armed planes on deck, you don't need to penetrate the flight deck. But getting through the ack to be able to take the shot in the first place is the real trick.
Title: 75mm gun!
Post by: PSYKO on January 21, 2003, 02:59:31 PM
enough to make u drule
nice pics
I WANT THOST GUNS IN AH
I WANT I WANT I WANT!
lol
Title: 75mm gun!
Post by: Tony Williams on January 22, 2003, 02:54:26 AM
Quote
Originally posted by Spritle
Also it was a fairly low velocity weapon and while it might have worked well against Japanese supply ships it would hardly scratch the paint on a carrier.

Spritle


Well, not THAT low.  It was around 2,000 fps (not including the attack speed of the aircraft) and this gun in a Sherman tank proved capable of punching through around three inches of armour.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and discussion
forum (http://forums.delphiforums.com/autogun/messages/)
Title: 75mm gun!
Post by: devious on January 22, 2003, 04:26:36 AM
Me want ME-410B w/BK50 5cm gun !!111
Title: 75mm gun!
Post by: Spritle on January 23, 2003, 04:55:41 PM
Sorry about this Wilbus, but I couldn't figure out how to post the entire thread so here are some quotes from a topic I started a while ago about the Hs129 and B-25H.

Wilbus
Quote
Difference between the 75mm in the HS129 and in the B25 is that the HS129's gun is a slightly remade anti tank ground gun, it's got a muzzle velocity of about 3300 feet per second and can penetrate about 130mm armor from 1000 meters distance (meaning it could kill every tank on the battle field easyily). On a typical pass, starting from 1000 meters away, it could fire around 3-4 rounds.

The B25H used a low velocity 75mm, short barrel slow speed of the shell, far from as effecitve against tanks as the HS129's gun. B25's guns was more a gun for softer targets like veichles and fuel dumps etc. Then again, B25 could still fly pretty well with the 75mm, the HS129 was reported to be a brick (even more so then without the gun).


Romeoman
Quote
Well, in real life they wouldn't be. While the B25H was designed to use its 75 mm versus shipping, it was costal shipping and anti-submarine patrols one had in mind for the gun. A destroyer is far to sturdy a ship to take much damage from a couple 15 lbs rounds.

Even your standard merchant ship could withstand a great deal of damage, especially the larger ones, altough this varied according to cargo (crude loaded tankers were rather vulnerable, for example).

That's why destroyers moved to greater calibers after 1905. Up untill then 75mm would suffice, as the destroyers of the time were about half as large as the later models (also, their primary function was to engage torpedo boats, and rate of fire was essential for that purpose). To be sure, it took a couple of hundred rounds to disable a destroyer (as proven in the Russo-Japanese war, where destroyer duels were mostly incoclusive, despite hits on both sides).

Destroyers of WWII were armed with guns from 120mm and up to 150mm. The weapon of choice for sinking destroyers were the 6'' guns of the light cruisers, firing 110 lbs shells. Still, several full hits were required to disable a destroyer.


So the fact still remains that the B-25H gun while great for hangers and such wouldn't do anything against carriers.

Spritle
Title: 75mm gun!
Post by: Tony Williams on January 24, 2003, 02:37:39 AM
The BK 7,5 was indeed a version of the PaK 40 anti-tank gun, and did have a much better performance than the Mitchell's M4, but not by as much as that: the shell was fired at 790 m/s (around 2,600 fps) intead of 600. The 3,300 fps figure probably refers to the tungsten-cored ammo, but I have no evidence that was ever used in the aircraft gun. Incidentally, I have one of the PaK 40's massive cartridges standing by my desk alongside the much smaller US one - an interesting contrast!

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and discussion
forum (http://forums.delphiforums.com/autogun/messages/)
Title: 75mm gun!
Post by: Karnak on January 24, 2003, 02:58:33 AM
I'd like a Mosquito FB.Mk XVIII with a 57mm Mollins gun.
(http://uboat.net/allies/aircraft/photos/mosquito2.jpg)
You can see the Mollins gun protruding from under the nose.
Title: 75mm gun!
Post by: J_A_B on January 24, 2003, 03:45:50 AM
And see the white puffy things behind that Mossie?  Those aren't clouds, it's gasoline vapors leaking from the plane.  All Mossies leaked more fuel than they actually used, which is why the Spitfire had a greater range despite carrying only 1/4 the fuel  :D


J_A_B
Title: 75mm gun!
Post by: Dr Zhivago on January 24, 2003, 05:01:28 AM
Anyone got more info about Italian Piaggo P.108A [Artigliere] with 102mm naval cannon at nose... ???
Title: 75mm gun!
Post by: Tony Williams on January 24, 2003, 07:30:08 AM
Quote
Originally posted by Dr Zhivago
Anyone got more info about Italian Piaggo P.108A [Artigliere] with 102mm naval cannon at nose... ???


It was an old (WW1) medium-velocity gun. It was installed and tested, but didn't enter service.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and discussion
forum (http://forums.delphiforums.com/autogun/messages/)
Title: 75mm gun!
Post by: Tony Williams on January 24, 2003, 07:54:57 AM
Quote
Originally posted by Karnak
I'd like a Mosquito FB.Mk XVIII with a 57mm Mollins gun.
 


Read all about the Molins gun, at: http://www.quarry.nildram.co.uk/Molins.htm

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and discussion
forum (http://forums.delphiforums.com/autogun/messages/)
Title: 75mm gun!
Post by: maxtor on January 24, 2003, 10:15:21 AM
I used to enjoy the Warbirds B25 with the big guns and the rockets.    I wish our attck version of the A20G had rockets sometimes (though I have no idea if they were ever so outfitted in war).
Title: 75mm gun!
Post by: Spritle on January 24, 2003, 11:13:59 AM
Tony,

Wasn't the M4 only used in a few B-25G's while all of the H models had the T13E1 75mm.  I'm not totaly familiar with either, but from what I can tell the T13E1 was basically just a lighter version of the M4.  Where there any other differences?  

My point wasn't that the B-25H would make a poor anti-tank weapon, but that it would make a poor anti-shipping weapon.  I don't think it could hurt a destroyer and certainly not a carrier.  Also I'm not sure, but I think the sighting system of the cannon ment that there was NO bomb sight.  Perhaps they were using bounce bombing techniques with these aircraft.  

It would be pretty good against a PT though or any of the LVT's, M-16, M-8, and M-3.  Probably not too bad against the Tiger or Panzer either.

Spritle
Title: 75mm gun!
Post by: Tony Williams on January 24, 2003, 10:11:04 PM
Quote
Originally posted by Spritle
Tony,

Wasn't the M4 only used in a few B-25G's while all of the H models had the T13E1 75mm.  I'm not totaly familiar with either, but from what I can tell the T13E1 was basically just a lighter version of the M4.  Where there any other differences?  

Spritle


Yes, the T13 (which was subsequently type-classified as the M5) was a much-lightened version of the M4, and fired the same ammo. Performance remained the same, and it stayed manually-loaded.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and Discussion forum (http://forums.delphiforums.com/autogun/messages/)
Title: 75mm gun!
Post by: SKurj on January 24, 2003, 11:14:27 PM
Wasn't there also a B17 fitted with a big gun for anti shipping work?


SKurj
Title: 75mm gun!
Post by: Rasker on January 25, 2003, 06:22:18 AM
I vaguely recall that one or more A26's was fitted with the 75 mm also,  I'd give up a few perks for that ride