North American PBJ-1K - USMC, Korea 1950-1953 (Finished, page 4)

[Wardukw]

I'm gonna throw another spanner in the works Raff mate 
Jon mentioned 20mm which i forgot about and yes ,,a bloody good choice for sure ,,just look at the carnage the Beaufighter did with its 4 x 20mm cannons ,,,but theres also another caliber to think about to and one which the USN might have had a play with ,,,37mm.. they did have a 37mm auto cannon ,,like the M4 ,,heres a link for it .
https://old-wiki.warthunder.com/M4_(37_mm)
This is a very plausible ..just to make ya life more annoying   
i do kinda dig the 50mm Bordcannon to 

[RAFF-35]

I'm gonna throw another spanner in the works Raff mate 
Jon mentioned 20mm which i forgot about and yes ,,a bloody good choice for sure ,,just look at the carnage the Beaufighter did with its 4 x 20mm cannons ,,,but theres also another caliber to think about to and one which the USN might have had a play with ,,,37mm.. they did have a 37mm auto cannon ,,like the M4 ,,heres a link for it .
https://old-wiki.warthunder.com/M4_(37_mm)
This is a very plausible ..just to make ya life more annoying   
i do kinda dig the 50mm Bordcannon to 

I see your point, but would the 37mm mess up a bridge or ship as effectively as a 50mm?

[Wardukw]

I'm gonna throw another spanner in the works Raff mate 
Jon mentioned 20mm which i forgot about and yes ,,a bloody good choice for sure ,,just look at the carnage the Beaufighter did with its 4 x 20mm cannons ,,,but theres also another caliber to think about to and one which the USN might have had a play with ,,,37mm.. they did have a 37mm auto cannon ,,like the M4 ,,heres a link for it .
https://old-wiki.warthunder.com/M4_(37_mm)
This is a very plausible ..just to make ya life more annoying   
i do kinda dig the 50mm Bordcannon to 

I see your point, but would the 37mm mess up a bridge or ship as effectively as a 50mm?

Well considering the fact that 20mm rds have done massive damage to ships i would say yeah ,,a HE or AP 37mm would do some pretty serious damage ,,the bridge of a ship isn't that well protected ,,fact 50cal can punch thru it ,,its not the main combat area ,,thats down in the hull which is far better protected ,,there's plenty of gun camera footage of fighters shredding ships ,,cargo ships aint armoured at all ..frigates aren't well armoured either ..a cruiser be it a light ,,medium or heavy can still be damaged by cannon rounds ,,hell even a battleships bridge isn't as protected as ya might think ..if ya look at the bridges of the Japanese ships they had this added armour which on the outside looked like they tied bed rolls to the ships...its just more armour . 

[Rick Lowe]

And the windows aren't usually armoured glass... extra shrapnel, to augment the steel and HE... 

[RAFF-35]

It's been a few days, so here's a few update pictures

[Wardukw]

  
That's coming along great matey 

[kerick]

You could put a searchlight in the nose of one tip tank and radar in the other.
With guns it's usually a compromise between a smaller caliber with a high rate of fire or a large caliber and slow rate of fire. Do you want a few hits with a big punch or many hits with a smaller punch.
The one that got away with providing both was the A-10.

[jcf]

A couple of notes about the Bk 50:
It had a pneumatic rammer rather than being recoil operated.
The endless belt in the magazine was moved by a pneumatic
system and it was reloaded via a loading port on the left rear
of the magazine.
The weight of the AP projectile was 2.06kg, HE 1.1kg.
Muzzle velocities were 835m/s and 960m/s respectively.

The main Achilles Heel of the installation in the Me 410 was that the Bk5 muzzle
velocity was much higher than the MG151/20 and MG13 that were also carried.
There was no way have the all of the guns set to converge on the same point thus
the 13mm MG and 20mm cannon couldn't be used for ranging.
The other issue was the one that effected all heavy cannon armed aircraft, air to air
and surface attack, the aircraft couldn't maneuver normally, it had to stay aimed at
the target, which made the aircraft vulnerable to opposing fighters and exposed the
surface attack aircraft to AAA, especially due to them having to operate at low level.
Which is why the 40mm gun Hurricanes were removed from service in Europe and the
Med.

The US .50 is closer to the 50mm AP round, having a higher muzzle velocity, but while
it's higher than the 50mm AP round it's much less than the HE round. Thus the ranging
issues would be similar. The HS404, US verrsions AN-M2 and the USN Mk.11 and Mk.12 developed from the AN-M2 are closer in performance to the Bk50 rounds and would be a 
better match.

As to the MK 214A being a viable weapon for development, the notion that it was some
great thing "with a better autoloader" is countered by a post-war interrogation of the
designer of the weapon which has a detailed description of the weapon. It's more 
complicated than the Bk50 and would likely have been a flop.  

[RAFF-35]

Minor progress update: First coat of paint has now been applied.

[Wardukw]

Oh I like that mate 👌 👍 😀
Very very nice work indeed 👏

[kerick]

Awesome!

[RAFF-35]

North American PBJ-1K – Super Strafer
The North American PBJ-1K was a heavily modified development of the NA-98X "Super Strafer," tailored for the U.S. Navy and Marine Corps. Designed as a versatile maritime strike and support platform, it combined speed, firepower, and rugged naval adaptations to fulfill multiple combat roles.
Powered by two 2,000 hp Pratt & Whitney R-2800-51 Double Wasp engines—shared with several other Navy aircraft for maintenance commonality—the PBJ-1K offered a dramatic performance boost over the standard B-25. With water injection available for short bursts of extra power, the aircraft reached 350 mph (563 km/h) at altitude and could climb to 10,000 ft in under five minutes, far surpassing its predecessor. Handling was also improved with squared wingtips, enlarged ailerons, and three-blade propellers fitted with large spinners, giving the aircraft a noticeably higher roll rate and smoother ride.
For naval operations, the PBJ-1K was strengthened and adapted with folding wings, an arrestor hook, and provision for drop tanks. Its mission set spanned anti-shipping strikes, submarine hunting, close air support, and search-and-rescue (SAR). A wing-mounted search radar enhanced maritime patrol capability, while updated sighting systems improved weapon accuracy. The defensive layout was streamlined: the rear gunner's position was deleted, and side blister guns were removed—though windows were retained to aid observation during SAR missions.
The PBJ-1K required a crew of four to operate. The crew consisted of the pilot, navigator/radio operator, flight engineer/radar operator and lastly, the gunner/observer.
Offensively, the PBJ-1K carried an impressive arsenal. It could mount rocket rails under its reinforced wings, carry bombs (such as M26A1 cluster bombs) or depth charges, and was equipped with a remote-controlled gun turret. The centerpiece of its armament, however, was the OB50C (BK 5 derived cannon) a formidable 50 mm weapon adapted from the German KwK 39/1. With a hydraulic autoloader and dual reflector/telescopic sight, the OB50C could destroy heavy bombers or surface vessels with a single high-explosive round—often fired from outside the range of return fire. Later experiments explored even more powerful 55 mm Mauser Mk 214-series guns, though these remained developmental.

[RAFF-35]

Extra photos.

[Old Wombat]

Good result! 

[Weaver]

That looks good - nice one!