Author Topic: Reduce the 0.5 cal hitpower (Read 902 times)

GRUNHERZ · « **Reply #30 on:** June 23, 2001, 04:31:00 PM »

Not talking abut jamming.

I am talking about barrel wear. This is where the barrel lining gets deformed due to friction and heat from the bullets passing through the barrel. This distorted the lining and killed the guns accuracy. This is one of the reasond many heavy squad MG,s have quickly interchangable barrels.

I have read specific accounts from US pilots in WW2 that they restriucted themselves to firing short bursts only so they dont ruin their aim from the guns linings getting melted. I think one example of this it was in Andersons book. It was also stated as one of the advantages of the Hispano over the the 50cal, during that Fighter Conference in late 1944, the one about which the book was written. Thee point was the 50cal linings could and would deform severly long before the full ammo load was expended unless fired in short short bursts.

Again these are facts about the US aircraft .50cals, which are easy to look up.

ra · « **Reply #31 on:** June 23, 2001, 04:55:00 PM »

The Joint Fighter Conference book tells how long the bursts could be, but I'm too lazy to look it up. It was something like 10 seconds for the first burst, then 2 second bursts from then on. The 20mm had a lower RoF and barrel wear was not as bad a problem.

The problem mostly occurred on strafing runs, as most pilots didn't spray very long in air combat.

ra

Hooligan · « **Reply #32 on:** June 23, 2001, 05:02:00 PM »

10 Seconds of fire is about one third of the ammo load of a Hellcat, Corsair or P-47.

Hooligan

[ 06-23-2001: Message edited by: Hooligan ]

Otto · « **Reply #33 on:** June 23, 2001, 05:51:00 PM »

Always remember this... The one's telling the stories are the ones that got back. Think about this...

Nashwan · « **Reply #34 on:** June 23, 2001, 05:52:00 PM »

Has anyone got the exact figures from the joint fighter conference?
Go on ra, laziness isn't good for you

Jigster · « **Reply #35 on:** June 23, 2001, 07:06:00 PM »

Quote

Originally posted by ra:
The Joint Fighter Conference book tells how long the bursts could be, but I'm too lazy to look it up. It was something like 10 seconds for the first burst, then 2 second bursts from then on. The 20mm had a lower RoF and barrel wear was not as bad a problem.

The problem mostly occurred on strafing runs, as most pilots didn't spray very long in air combat.

ra

Just a note, but the limits put on MG bursts in aircraft is not soley because of barrel wear (in an exclusive sense) The electric system and servos for the remote triggers on the gun pull alot of power. The system will lose sufficent power after so many sustained seconds, and has to given brief periods to recharge off the generator.

Infantry and armored vehicles carried extra barrels because it was not uncommon for them to several boxes or belts in a suppressive fire role, without any form of cooling. Aircraft, on the other hand, had some cooling from airflow, and rarely had more than 400 rpg, less than most .50 cal equiped units had.

Oh one other note was the improvement of the propellant in the M2 round, it's the only real reason penetration increased much since WWII.

[ 06-23-2001: Message edited by: Jigster ]

ra · « **Reply #36 on:** June 23, 2001, 07:19:00 PM »

Ok, from page 162 JFC. To save rifling bursts should be limited to 75 rounds for the first burst and 25 rounds per burst thereafter.

All that work, now I need a beer.

ra

Nashwan · « **Reply #37 on:** June 23, 2001, 08:14:00 PM »

Thanks ra

Now to be even more of a pest, do you know what the limits were for the Hispano?
I'll buy you a beer if we ever meet

CJ · « **Reply #38 on:** June 24, 2001, 12:51:00 AM »

Hmmm... I always thought of Young's modulus as a measure of material stiffness. Glass has a high young's modulus, but is easy to shatter with an impact. There are lots of thigns with a very high modulus, but a low ultimate yield strength, since these materials don't give very much before they crack. I think armor is better judged by its impact toughness, which is a combination of elastic, inelastic, and ultimate tensile or shear strength properties. Fiberglass makes great structures, but it's terrible at stopping bullets compared to materials like kevlar or lexan, which deform, and absorb energy, yet still have a high ultimate breaking strength.

CJ

Quote

Originally posted by DeeZCamp:
Is this how Aces does Damage?

Young's Modulus is the STRESS of a material divided by it's STRAIN. That is how much the material YIELDS for each pound of load put on it.
Put another way, it is a measure of the STRENGTH of a material, and is commonly used to measure the strength of metals and other materials used in aircraft and weapons systems.

check out www.youngsmodulus.com

-Deez out..