XF5F Skyrocket test. Was it ballasted for weapons during test?

[pinsog]

I'm looking at the test sheet for the XF5F Skyrocket.
It says:
empty weight is 7990 pounds
normal weight is 10,021 with 178 gallons (1,100 pounds) 7990+1,100=9,090 pounds+200 pound pilot=9,290+150 in oil
Where did the other 581 pounds come from?

overload is 10,892 with 277 gallons (1,713 pounds) 7,990+1,713=9,703 pounds add 200 for pilot=9,903+150 in oil
Where did the other 839 pounds come from?

Do you think this aircraft was ballasted for the weight of weapons for the tests?

http://alternatewars.com/SAC/XF5F-1_and_XFL-1_PD_-_26_December_1942.pdf

 

[Capt. Vick]

I have the Ginter book on this bird, I could check if I remember.

 

[Shortround6]

It might look good.
The F2A-2 Buffalo with 4 guns had a fixed useful load of 628lbs over and above the empty weight, to which was added 1443lbs of disposable load. for total useful load of 2061lbs.

In the fixed useful load was the 200lb pilot, 151lbs of communications/navigation gear, and 277lbs worth of guns. The disposable consisted of 83lb of oil for one engine, 270lbs worth of ammo and 1080lbs of fuel (180 US gallons)

Take your 581lbs and subtract even 130lbs of radio gear and you have 451lbs, subtract 277lb of four .50 cal guns and you have 174lbs.
.50 cal ammo is about 20lbs per hundred so 174lbs equals 145 rounds per gun. Now perhaps they didn't use quite as much oil and traded the weight for more ammo? Using more fuel would require full oil tanks?
USN used some strange (to us) accounting in the early years and often had Normal or light loading's for fighters and considered a fighter with full internal tanks and full ammo (or even full gun load) as overloaded.

Now please note that the F4F-3 has a weight of 286lbs listed for the same four .50 cal guns and F4F-3s also carried 7.9lbs of pyrotechnics (flares) and a 13.7 lb gun camera in the fixed useful load.
What they were figuring for gun and ammo weight if "normal" and overload condition fo the F5F would be interesting to figure out.

 

[pinsog]

I don't see any other info except empty weight with remaining oil and fuel. But, I can't think of anything else that would substantially add to the empty weight besides weapons. They could have used 4 50's or 2 50's and 2 30's, both were mocked up. They said that when they changed to 4 50's they wanted 400 rpg. It may have been guns only and no ammo.

Of course that is the test with the quote about the XF5F came in first and the Spitfire came in a distant 2nd and the reason they didn't go with the XF5F was due to spares and complexity