Author Topic: Buff gun formula (Read 331 times)

Viper17 · « **on:** July 02, 2002, 10:54:27 AM »

In my time off from school I was working on some math when I realised a formula to test why the guns on the B17 work so good. Well here it is.

A= the relitive speed of the B17G
-
B= the bullet velocety of a Browning M2 .50cal
+
C= Closeure speed of any aircraft
=
D= Enhanced damage to aircraft C because of A-B+C=D

Add in stuff to figure out the dammage efect. This is only a test of my Algebraic skills....witch are limited.

Kweassa · « **Reply #1 on:** July 02, 2002, 01:09:09 PM »

you forgot:

E: "multiple gun positions converging at a single aim point with incredible(well... "Bull Shi*" seems more appropriate) accuracy"

F: "buffs outmaneuvering fighters at extreme high(BS

) altitudes and gaining ideal gunner angles"

G: "gunners extremely hard to kill off"

H: "incredibly stable guns not giving out a single vibration when fired"

...

so

A+B+C+E+F+G+H

equals...

Sleight · « **Reply #2 on:** July 02, 2002, 01:24:45 PM »

lmao!

UnDeth · « **Reply #3 on:** July 03, 2002, 03:53:27 PM »

LOL !!!

Tony Williams · « **Reply #4 on:** July 03, 2002, 04:27:32 PM »

Agreed about the poor hitrate of defensive guns in RL (even if you believe the gunners' claims, they still used up ten times as much ammo per kill as the fighter escorts.

To return to the original point - a substantial advantage in penetration is only achieved in a head-on attack, when the planes are flying towards each other. In a tail attack, the penetration is much the same. In a beam attack, it will be a bit better. Nothing to get excited about, however.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk
Discussion forum at: http://forums.delphiforums.com/autogun/messages/

Thrawn · « **Reply #5 on:** July 03, 2002, 04:42:35 PM »

LOL!

HoHun · « **Reply #6 on:** July 03, 2002, 04:49:30 PM »

Hi Tony,

>Agreed about the poor hitrate of defensive guns in RL (even if you believe the gunners' claims, they still used up ten times as much ammo per kill as the fighter escorts.

As they overclaimed by a factor of ten, I don't dare to guess what their hit percentage was :-)

However, I've seen mention of British gunnery tests from the 1930s when powered turrets were evaluated versus hand-held guns. (The tests finally lead to the Boulton-Paul Defiant fighter.)

According to the article I read, powered turrets had a great advantage over hand-held guns in accuracy, but what I'd really like to know is what kind of absolute accuracy they reached with either type of guns.

I wonder if you ever found some information like that anywhere?

(The article in question was an old Flug Revue feature on the Defiant by Hans Redemann.)

Regards,

Henning (HoHun)

Tony Williams · « **Reply #7 on:** July 03, 2002, 10:49:18 PM »

Hi Henning,

Yes, you are right; pre-war British tests demonstrated that turret guns were several times as effective as flexibly-mounted ones. I've not seen any figures for their absolute accuracy, though.

One thing you can be sure of; they scored far better in practice than they ever did in combat

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk
Discussion forum at: http://forums.delphiforums.com/autogun/messages/

Fester' · « **Reply #8 on:** July 04, 2002, 12:17:32 AM »

Relying on a high school education here guys, so bear with me, but....

If a machine gun round passes through the skin of the fuesalage at 2700 fps, I dont see it doing any more damage if you add closure speed to that.

Yes the realized energy of the round will be greater but unless the round comes to a complete stop in the airframe then all of its energy was not dissipated anyway.

As an example, if I shoot through a piece of cardboard with a 600fps 9grn .177 pellet, and shoot through the same piece of cardboard with 1000fps 9grn .177 pellet the damage to the cardboard is roughly equal.

The round only imparts all its energy when it comes to a complete stop. I dont know that that happens shooting through the wings and fueselage of the aircraft with these rounds. There are portions of the aircraft that have round stopping power, engine, wing root, pilot armor etc...

Id be curious to see how many .50 rounds on average go completely through a plane and how many are stopped short.

Tony Williams · « **Reply #9 on:** July 04, 2002, 02:45:58 AM »

I would have expected a .50 to go through most aircraft structures (although rifle-calibre bullets were stopped fairly easily) and you are right that velocity didn't matter much in that case - but armour plate was a different issue. The more velocity the better, as German fighters tasked with attacking B-17s were increasingly heavily protected, especially at the front.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk
Discussion forum at: http://forums.delphiforums.com/autogun/messages/

fdiron · « **Reply #10 on:** July 04, 2002, 02:51:36 AM »

50 cal rounds will punch through the metal skin of a B17 very easily. However, if you have ever been inside of a B17, you will see that there are many thick metal ribs all along the aircraft. There are ammo boxes, control cables, bulk heads, catwalks, radio equipment, oxygen tanks, seats, instrument panels, and (usually) humans inside. Once a round enters a B17, its not very likely that it will exit straight through. This is especially true for the wings (fuel tanks, ribs, engines, etc etc).