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Stafroty
07-01-2007, 01:09 PM
how big is the recoil of mk108 cannon in the game? is it really that hard when u compare it to almost same cannon of this video. Russian ags 17 autogrenade launcher, based from mk-108 cannon. operates same way.

http://video.google.com/videoplay?docid=3570089259317807254

Notice, that the man in video even shoots that friggin cannon while handheld.

FliegerAas
07-01-2007, 01:53 PM
But you know that the AGS17 has a much lower muzzle velocity and fires at a lower rof...

3.JG51_BigBear
07-01-2007, 02:29 PM
Nifty weapon. FliegerAas is right, rate of fire and muzzle velocity make all the difference.

Blutarski2004
07-02-2007, 05:13 AM
I have recently read a claim that the Mk108 had jamming problems when fired under high G. Has anyone seen anything to confirm this?

Just curious.

AnaK774
07-02-2007, 05:53 AM
Blutarski, as did all belt fed aircraft weapons.
Some were more and some less prone for feeding
jams.

If you read Helmut Lipfert's "Fighterpilot on eastern front"(translation of translations translation will chk original name when i get it back from loan) he seems to be holding short stack on weapon reliability

Blutarski2004
07-02-2007, 09:46 AM
Originally posted by AnaK774:
Blutarski, as did all belt fed aircraft weapons.
Some were more and some less prone for feeding
jams.

If you read Helmut Lipfert's "Fighterpilot on eastern front"(translation of translations translation will chk original name when i get it back from loan) he seems to be holding short stack on weapon reliability


..... Thanks Anak. I agree that belt-fed weapons had/have a greater tendency to jam under high G conditions, the 50cals in the P51B wing being a well-known example. This is the first time though that I had come across any mention of the Mk108 having a notable problem.



Interesting.

Kettenhunde
07-02-2007, 10:03 AM
This is the first time though that I had come across any mention of the Mk108 having a notable problem.

IIRC on the gondola installation, the plugs for the solenoid would come undone at high G in the initial installations.

IIRC, The first Dora's also had a problem with solenoid grounding out on the MG cover in flight.

All of these of course were fixed.

All the best,

Crumpp

Kurfurst__
07-02-2007, 10:50 AM
Originally posted by Blutarski2004:
I have recently read a claim that the Mk108 had jamming problems when fired under high G. Has anyone seen anything to confirm this?

Just curious.

I've seen some talk on this, and probably it's related to the belt linkages streching under the strain as the big cannon pulled the belt into the gun. Under high G this may have put on occasion too much strain on the heavy 30mm belt the gun was pulling in. Note that nowadays cannons of the 20, 27 and 30mm class have a different , more robust belt than in WW2. 30mm Chain Gun, for example.

Anyway for what it's worth, it seems it was certainly not something automatically occuring during high-G. See Tobak's account flying a G-10/U4 late in the war via George Punka's 'Messer'.

http://i38.photobucket.com/albums/e133/Kurfurst/small_100TobakMK108G-10.jpg

Blutarski2004
07-02-2007, 12:20 PM
Thanks to K & K fo rthe data. I wouldn't think that any such jamming problem was at all dire or inimical to the effectiveness of the weapon - just a "housekeeping" matter.

zugfuhrer
07-02-2007, 01:46 PM
The MK 108 got the same precision as the ags 17, the precision of a mortar.

Abbuzze
07-02-2007, 02:34 PM
I think it should be possible to judge the recoil by calculating the cinetical energy of a bullet, and then calculate it for a 1 or 2 sec burst of fire.

1/2*mass*muzzlevelocity^2*rof

Grand_Armee
07-02-2007, 10:29 PM
The Squadron "In Action" book covering the later marks of the bf-109 do mention early jamming problems with the 30MM Cannons.

However, this was improved but not entirely eradicated.

Anybody ever play 'European Air WAr'? One to all of the 30's on the Me-262 jammed up on every mission.

Kurfurst__
07-02-2007, 11:58 PM
Originally posted by Abbuzze:
I think it should be possible to judge the recoil by calculating the cinetical energy of a bullet, and then calculate it for a 1 or 2 sec burst of fire.

1/2*mass*muzzlevelocity^2*rof

It's a bit more difficult because there are also the recoil elements and the heavy bolt that gradually consume the backward acting kinetic energy element of the round as it leaves the barrel.. the MK 108 was a blowback design.

In any case, it's unlikely the MK 108 itself would move at all, it was fixed directly to the rear of the engine block, and via it, the whole aircraft. It's pretty unlikely it could have rocked a 3+ ton aircraft this way, no flexing elements, just a huge lump mass vs. gradually applied inertia. If it would be in the wings it probably would be different, because then it would flex and twist the wings somewhat, and by this way, rock the aircraft more than in it's original installation.