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View Full Version : Ammunition & Other Weights on a Website?..............



LEBillfish
12-16-2005, 09:18 AM
Hi all & especially to you Quartermasters/Loadmasters;

Trying to really fine tune some information for some research on the Ki-61, yet am having no end of trouble finding 2 things.......

1. The Specific Gravity or better still end all weight for 92 Octane Japanese Aviation fuel.

2. The actual "round"(case+powder+primer+slug) not bullet/projectile weight OR better still the weight per a belt of X number of rounds for the following......

Type 89 MG: 12.7Kg/gun, 7.7mm x 58 SR XXX/rd, 500 r/g
Type 1 MG Ho-103: 23Kg/gun, 12.7mm x 81SR xxx/rd, 250 r/g
Mauser 151/20 Cannon: 42Kg/gun, 20mm x 82 xxx/rd, 120 r/g

Thanks for any help you can give.

LEBillfish
12-16-2005, 09:18 AM
Hi all & especially to you Quartermasters/Loadmasters;

Trying to really fine tune some information for some research on the Ki-61, yet am having no end of trouble finding 2 things.......

1. The Specific Gravity or better still end all weight for 92 Octane Japanese Aviation fuel.

2. The actual "round"(case+powder+primer+slug) not bullet/projectile weight OR better still the weight per a belt of X number of rounds for the following......

Type 89 MG: 12.7Kg/gun, 7.7mm x 58 SR XXX/rd, 500 r/g
Type 1 MG Ho-103: 23Kg/gun, 12.7mm x 81SR xxx/rd, 250 r/g
Mauser 151/20 Cannon: 42Kg/gun, 20mm x 82 xxx/rd, 120 r/g

Thanks for any help you can give.

LEBillfish
12-17-2005, 08:18 AM
Not 1 person here knows of one decent site or report?

Hydra444
12-17-2005, 09:20 AM
My only guess on the weight of a 7.7x58mm round would be that its weight would be similar weight to that of a Russian 7.62x55(?)mm round.

Its hard as Hades to find information this specific for WW2 aircraft,let alone for Japanese planes.But I can try and see what I can dig up as well.

What exactly are ya doing this research for?

LEBillfish
12-17-2005, 09:44 AM
Weight variations in the Ki-61 due to changes in loadouts......"specifically"....not by just stated numbers.

Low_Flyer_MkII
12-17-2005, 09:52 AM
ImpStarDeuce recently posted these links. Any good to you?

http://members.cox.net/rg_lunatic/gunpage/

http://www.quarry.nildram.co.uk/WW2guneffect.htm

http://www.ww2guide.com/guns.shtml

http://www.geocities.com/CapeCanaveral/Hangar/8217/fgun/fgun-fr.html

LEBillfish
12-17-2005, 11:58 AM
Yep, second one sure did...........anyone care to argue out my fuel weight to finalize it?......ALso would be nice to have belt or link weights as well though minimal.

Type 89 MG: 12.7Kg/gun, 7.7mm x 58 SR .024Kg/rd, .008Kg/link, 500 r/g = 16Kg
Type 1 MG Ho-103: 23Kg/gun, 12.7mm x 81SR 82g/rd, 250 r/g = 20.5Kg+link weight
Mauser 151/20 Cannon: 42Kg/gun, 20mm x 82 205g/rd, 120 r/g = 24.6Kg+link weight

92 Octane Fuel (est): 6#/gallon = .286Kg/liter
750l = 214.5Kg
550l = 157.3Kg
500l = 143.0Kg

Why this matters..........A number of captured Ki-61's were tested, their weights off from stated Ki-61 weights. However, the Ki-61 underwent some minor refinements. Little additions of armor, changes in fuel tanks and lastly armament. So by finding differences of say 30-100+Kg, the actual series of serial number can be determined and from that the varience in model then helping to explain performance irregularities.

Thanks for all your help http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

hamselv2
12-17-2005, 01:08 PM
I think there is an error in your calculation.

1 lbs = approx. 0,454 kg
1 gallon = approx. 3,79 liter

If 1 gallon weighs 6 x 0,454 kg the numbers you have given ends up with this specific gravity: 0,72 kg/liter.
The specific gravity of 'normal' gasoline is approx. 0,7 kg/liter.

MC202zipper
12-17-2005, 02:10 PM
EDITED:
OOPS! Looks like I didn't noticed LowFlierMkII post & LEBillfish answer....the truth is that I started answering just after Hydra444 message, and I nearly finished typing the answer about those good links from ImpStarDeuce post, then I had to leave the PC in the middle of it...came back some three good hours and hit enter.... anyway this is it..

Hello!

I think you will find the data you need in one or more of these pages:

Lunatic's WWII Aircraft Gun Ballistics Page
http://members.cox.net/rg_lunatic/gunpage/
the projectile weight are listed along LOT of datas, not round weight, sorry, but interesting. IMHO worth a look

WORLD WAR 2 FIGHTER ARMAMENT EFFECTIVENESS by A.G Williams & E. Gustin
http://www.quarry.nildram.co.uk/WW2guneffect.htm
here you find both round & projectile weight for many weapons included the one you need.
7.7x58 isn't listed, but as far as weight goes IMHO you can refer to the .303 7.7x56... notice how both the .303 & german 7.92x57 are 24grs..... I think that the odds are that even the japanese round weights 24grs. Lot of datas in this site as well as a very interesting discussion.

The site I linked is part of
CANNON, MACHINE GUNS AND AMMUNITION by A.G.Williams
http://www.quarry.nildram.co.uk/index.htm
well, this is a TOP site and mr. Williams is a well known expert about weapons

And, as you are into japanese aviation, check this
http://www.j-aircraft.com/faq/aircraft_weapons.htm
it's a nice page and is part of a bigger site... nice infos on weapons & some obscure subjects in IJAF

About the specific gravity of 92 octane japanes wartime fuel I think the answer is really a tough one, if there is a single answer to give.
Even at today's stringent standards, fuel from a specific brand and specific rated octane can vary its gravity as much as 2 or 3%... say that a racing 100 octane unleaded fuel from the same brand can vary between 0.74 & 0.76.. so I think it will be a difficult answer.
Actually most automotive standard gasolines weighs about 6.2Lbs/Gal(2.810Kg/Gal or 2.810Kg/3.785Lt as result we have 742grs/Lt) that gives us a 0.74204 specific gravity but if we consider automotive racing fuel (IMHO should be very close to aviation fuel of the 40s.. I am only guessing here...) we can find fuels as low as 5.8Lbs/Gal(2.63Kg/Gal > 2.63Kg/3.785Lt gives 698Grs/Lt) so a 0.698 specifig gravity ratio.
Still trying by comparison, as much more datas are available, did you try to look for german wartime fuel datas?
Sorry if this is a stupid answer (or no answer at all...).

Fuel links, small infos here & there in each page:
http://mustangandfords.com/techarticles/30643/

http://www.totalmotorcycle.com/downloads/gasoline-RacingGasolines.htm

http://www.off-road.com/dirtbike/rick/gas-tech_part1.html

S!
MC202zipper

LEBillfish
12-18-2005, 08:43 AM
Thanks guys for your help I'll keep looking to get firm answers as to both as sadly I'm finding conflicting data...