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View Full Version : FW190A8 boost & the MK103 VS MK108



XyZspineZyX
08-08-2005, 05:53 AM
Fellow pilots
What effect does the Boost on the FW190A8 have on the plane, does it make the plane go faster or does it cool the motor thus allowing you to fly at 110% throttle longer? With the boost on the BF109G6AS-K4 I have found I have to engage the boost when the motor is at idle or the motor fails, this is not the case with the FW190A8 &A9. I have "as yet" had the motor on the FW190A8/9 fail when engaging the boost.

Next question, apart from the difference in barrel length, what is the difference between the MK103 & MK108 30mm cannon? The MK103 is carried externally on the FW190 & the MK108 can be carried inboard, is there a difference in muzzle velocity & damaged caused by both types of cannon?

tsactuo
08-08-2005, 06:03 AM
I think the boost of FW190-A8 increase the speed, as RPM and ATA go up when it is enabled.

As for the MK108/103. I think that the MK103 have better Muzzle Velocity but lower Rate of Fire. I also think they are heavier for the aircraft and better against ground units and heavily armored targets (bombers). I always preffer MK108 for air battles in the FW, even against bombers. Since they are not Gunpods but fixed, and the aircraft performance difference to the standard 20mm MG is minimal to none.

Xiolablu3
08-08-2005, 06:22 AM
Mk103 has a lot more explosive in it allowing it to have a faster muzzle velocity (flatter trajectory) and gennerally be a bit more effective.

It is however much heavier and the ammo weighs a lot more.

There was a picture of MK108 vs MK103 shells printed here a while back (well it had all the ammo lined up against each other on the pic) The Mk103 is a lot bigger.

The mk108 was made as a light powerful gun which aircraft could carry without adding too much weight.

Jaws2002
08-08-2005, 08:20 AM
About the guns. If you look in this table you'll see the difference. Mk 108 has two advantages:
-Verry light gun allowing it to be instales in small fighters. (60kg compared with 141kg)
- High rate off fire, If you hit something is a good chance you'll hit with more then one shell.

Mk103 has one advantage, it has a much higher muzle velocity, so the shell won't drop as much allowing you to shoot bombers at long range from outside their deffensive gun range.
In FW-190 the 108 is better: Monted inside the wing, not much performance loss.

Kocur_
08-08-2005, 08:42 AM
To above information let me add that MK108 was a automatic weapon using the simplest priciple of action for automatic weapon, that is lock blow back, the same used in weaker pistols and most of mashine pistols.

Lock in never locked with barrel like in gas operated or barell recoil operated weapons. All you do is use heavy lock with spring behind it. During movement of projectile in barrel gases pressure affects both projectile and lock. The lock is heavy enough not to move back more during in-barrel projectile movement than thickness of case bottom, i.e. case is still supported by chamber walls as long as there is high pressure in barrel. After projectile has left the barrel, the lock has already enough energy to do all the work to operate weapon.

Limit of this principle is pressure in barrel and barrel lenght. Thats why MK108 is simple and light but has short barrel and uses weaker ammo than locked weapons like MK101 and MK103, because:

mass of projectile x velocity of projectile = mass of lock x velocity of lock

If you make first bigger, the heavier the lock must be.
MK108 was a very good compromise.

Because of relative low muzzle velocity AP projectiles were sensless, so MK108 was had in belt cartridges with one type of projectile exclusively, that is (veryhttp://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif)HE: Minengeschoss.

Btw.: all WW2 20mm Oerlikon cannons worked this way (MG FF(/M), Japanese navy type 99 on A6M)

Atomic_Marten
08-08-2005, 10:35 AM
Originally posted by Xiolablu3:
There was a picture of MK108 vs MK103 shells printed here a while back (well it had all the ammo lined up against each other on the pic) The Mk103 is a lot bigger.

The mk108 was made as a light powerful gun which aircraft could carry without adding too much weight.

http://img.photobucket.com/albums/v442/Atomic_Marten/LW_ammo_500res.jpg

Jaws2002
08-08-2005, 01:01 PM
Originally posted by Atomic_Marten:
http://img.photobucket.com/albums/v442/Atomic_Marten/LW_ammo_500res.jpg

Oh man look at the size of that 103 http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif
(thinks at the Pfeil) http://forums.ubi.com/images/smilies/59.gif http://forums.ubi.com/images/smilies/784.gifhttp://forums.ubi.com/images/smilies/59.gif

Man i'd love a Ta-152C with 1xMk103+4x Mg151/15)
too bad the model was messed up http://forums.ubi.com/images/smilies/cry.gif

Xiolablu3
08-08-2005, 01:24 PM
Thanks Atomic Martin, thats the one!

http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Is the 20HS404 Hispano?? It looks a lot bigger than the german 20mms.

Maybe its a trick of the eye and its actually just longer and thinner. Was the Hispano known to have more explosive in than the MG151?


And what is the 20OE round? Russian?

Kocur_
08-08-2005, 02:25 PM
Hispano Suiza HS 404 http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Produced in UK under licence as British Hispano.
Mk.II initially, Mk.V redesigned, later in Tempest

"a lot bigger" is the case, because it held more propellant. In terms of kinetic energy Hispano was more powerful, but MG151/20 Minengeschoss projectile had much more explosive in it.

"20OE" is Oerlikon for MG FF

Xiolablu3
08-08-2005, 02:41 PM
Thanks for that info Koncur http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif Much appreciated m8.

LStarosta
08-08-2005, 03:14 PM
I am pretty sure that showing pictures of sex toys and other "personal" paraphenalia is not allowed.

Please remove that, Marten.

XyZspineZyX
08-08-2005, 11:09 PM
Thanks for all the info guys, do any of you believe that the MK103 has potential for tank busting, considering the top armour is generally thinner? & I am talking about trying to take out T34/85s & IS2s or should I be using the SC 500 bomb & improving my divebombing skills?

Jaws2002
08-09-2005, 12:57 AM
Use the 110 with the Bk3.7 or the Me262 with that monster 50mm cannon

Xiolablu3
08-09-2005, 03:21 AM
30mm is good in FB/PF for tank busting.

Not tried it on the King Tiger but on the light and medium tanks 30mm does the job.

Even 20mm does the job on some tanks but you need to hit them a lot.

Atomic_Marten
08-09-2005, 06:37 AM
Originally posted by LStarosta:
I am pretty sure that showing pictures of sex toys and other "personal" paraphenalia is not allowed.

Please remove that, Marten.

I wont, unless you have a better gear.