Author Topic: PLS HT look into Breda MG modelling! (Read 3911 times)

Hooligan · « **Reply #15 on:** January 20, 2002, 01:38:47 PM »

Check out:

http://www.lvcm.com/jayb/ahgun102.htm

The information is a bit dated but nonetheless pertinent.

Hooligan

LUPO · « **Reply #16 on:** January 20, 2002, 03:08:13 PM »

I found different specifications for the gun used:

Company Calibre Weight Feed Rpm Mv
----------------------------------------------------------------------------
Breda SAFAT 7.7mm 12.5kg Belt 900 730ms
Breda SAFAT 12,7mm 28kg Belt 700 760ms

Italian 7.7mm and 12.7mm Breda SAFAT machine guns were generally efficient and reliable, using a mix of solid, incendiary and tracers bullets. The 12.7mm gun outranged the machine guns of their opponents with a close punch as good as the US 0.5"
quote from COURAGE ALONE by Chris Dunning, Hikoki publications

LUPO · « **Reply #17 on:** January 20, 2002, 03:34:01 PM »

BTW Wotan nice film.
I have the same film in VHS (the whole one) and you can definitly see there that the destructive power of Breda MGs is, if not impressive, effective and lethal against P40s, Spitfires and Blenheims.

Hooligan · « **Reply #18 on:** January 20, 2002, 03:46:13 PM »

LUPO:

My rate of fire information is from Aces High (i.e. I measured it with a stop watch offline in AH). Part of the problem is that the 12.7mm guns are synchronized to fire through the propellor and this always results in a signifcant decrease in the rate of fire. In the few instances in which I have found Rate of Fire information from archival sources, the AH figures have always matched. I trust HTC's research much more than I trust Gustin's for example.

As far as they quote you gave us: US .50 rounds were significantly heavier and faster than the Breda rounds. There is no way that a 37g round going 760m/s is going to outrange a 43g round going 928 m/s. Simply put, Chris Dunning is wrong.

The C.202 is armed with 2 slow firing 12.7mm and 2 slow firing 7.7mm. This is very light armament, possibly the equivalent of 2 US .50s. By mid-war everybody felt the need to give their fighters 3 or 4 times this much firepower. Is it any wonder that the guns seem weak in AH?

Hooligan

LUPO · « **Reply #19 on:** January 20, 2002, 04:25:16 PM »

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Hooligan wrote: Simply put, Chris Dunning is wrong.

This is possible. I'm checking out different sources in order to verify.

Quote

The C.202 is armed with 2 slow firing 12.7mm and 2 slow firing 7.7mm. This is very light armament, possibly the equivalent of 2 US .50s.

Nobody cannot admit it: IS a light armament.
But the comparison with 2 US .50s is quite opinable.

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Is it any wonder that the guns seem weak in AH?

No wonder, but weak is quite different from useless...
You have to think about the whole damage modelling in AH, where gun effects are generally overmodelled. The feeling is that the only exception are just the poor Breda MGs. Consider besides that I'm not speaking about 202 armament in MA wich is a late war arena, but about 202 efficiency in CT Stalingrad!

Vermillion · « **Reply #20 on:** January 20, 2002, 05:04:13 PM »

LUPO

TM 9-1985-6 Italian and French Explosive Ordnance (March 1953); 213 pages, 282 illus. Price 22.00 {Item No.2959}

Here is a document you can order that contains the hard data collected by the US on Italian armaments after the war. I own the Japanese, both Germans ones, a US one, and Hooli owes me the Brit one

The Manual can be ordered from this link.

http://www.military-info.com/MPHOTO/P110.htm

They're very good. If you get it, I'll trade you copies of some of the others.

brady · « **Reply #21 on:** January 20, 2002, 07:08:57 PM »

I have the scans of the pages from the Manual he refers to that pertain to the debat at hand, namely the 202 mg ammo pages, with cross sections of the ammo, if anybody wants I can scan theam and post team hear.

Wotan · « **Reply #22 on:** January 20, 2002, 07:28:36 PM »

please do brady

one other thing elrkonig my squaddie was on an 8 kill sortie in a 202 when i logged off earlier

who'd a thunk it ............

Tony Williams · « **Reply #23 on:** January 21, 2002, 06:12:09 AM »

Quote

Originally posted by Hooligan
LUPO:

My rate of fire information is from Aces High (i.e. I measured it with a stop watch offline in AH). Part of the problem is that the 12.7mm guns are synchronized to fire through the propellor and this always results in a signifcant decrease in the rate of fire. In the few instances in which I have found Rate of Fire information from archival sources, the AH figures have always matched. I trust HTC's research much more than I trust Gustin's for example.

Hooligan

I'm very interested in this as I have found synchronised RoF information to be extremely rare. The only one I know of for certain is for the Soviet 12.7mm UBS, which fired at 800 rpm instead of 1,050 rpm for the non-synchro versions.

If you can publish or email to me what you have on this, and the sources, I would be very grateful.

Tony Williams
Author: "Rapid Fire: The development of automatic cannon, heavy machine guns and their ammunition for armies, navies and air forces"
Details on my military gun and ammunition website:
http://website.lineone.net/~a_g_williams
Gun and ammunition discussions at:
http://www.delphi.com/autogun/messages

LUPO · « **Reply #24 on:** January 21, 2002, 07:56:13 AM »

Thanks VERMILLION, this source is extremely interesting to me.
Unfortunatly they cannot ship orders to Italy anymore...

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We are only shipping orders to customers in the United States, until further notice, because of the National Tragedy (09/11/01).

With the only exception is, that we will ship outside of the United States to United States Military personnel in military units at Military addresses (like APO's, and FPO's) (01/01/02). Note: Military personnel must send a photocopy of their ID card along with their order.

LUPO · « **Reply #25 on:** January 21, 2002, 08:00:23 AM »

Yep, Brady. I would be very interested to read that page.
Please if you can send me an e-mail or publish it here.
I greatly appreciate any new source about this argument.

Regards,

-lynx- · « **Reply #26 on:** January 21, 2002, 10:20:05 AM »

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Nobody cannot admit it: IS a light armament. But the comparison with 2 US .50s is quite opinable.

Sorry Lupo, it's a fact:

2 US 50 cals firing 43g projectiles at 800 rpm with muzzle velocity of 928 m/s deliver ordnace with 1062 kgm/s of impulse power per second (not sure what the proper english term is but it's "stopping power", mass x velocity). Combined impact of both 7.7 and 12.7 Breda guns would be just 904 kgm/s per second.

This, in turn, means that under ideal conditions (reported rate of fire/muzzle velocity) 2x7.7 + 2x12.7 Breda SAFAT MGs were just 85% as efficient as 2x US 50cal Browning M2 MGs. If you compare their kinetic energy (mass x velocity squared) delivered by each round Breda projectile gives only 53% of Browning one...

These are obviously just rough calcs omitting loads of factors but they give an idea of comparative gun efficiency...

MANDOBLE · « **Reply #27 on:** January 21, 2002, 10:31:12 AM »

lynx, what about the explosive effect of Breda's HE rounds?

-ammo- · « **Reply #28 on:** January 21, 2002, 11:19:54 AM »

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Originally posted by MANDOBLE
lynx, what about the explosive effect of Breda's HE rounds?

The explosive content of a light round such as 30 or 50 caliber is not the destructive force as it is in a heavier round like 30mm-- heavy artillery. Comparitively, a light MG rounds kinetice energy bares the destructive force. The browning 50 cal is hard to beat in this category. Lots of muzzle velocity, heavy projectile, flat trrajectory...all this equals a very good AC gun platform.

Hooligan · « **Reply #29 on:** January 21, 2002, 12:06:55 PM »

I will say it again:

EVERYBODY added explosive or incendiary effects to their MG ammo. In HMG ammunition this typically turns out to be about 1g of incendiary or explosive compound in a projectile (that is like 1/10 of a teaspoon, or .5ml). Everybody experimented with both HE and Incendiary rounds. Some preferred HE in their MG rounds and some preferred Incendiary.

There is nothing particularly unique about Italian MG rounds concerning their explosive content.

Hooligan