Your armament?

[Lunatic]

Lunatic:

Sorry Lunatic, what's a B20?

The B20 was basically a necked up version of the 12.7mm Berezin machine gun. It fired the same ammo as the ShVAK (the "OF" HE-Frag round carried 6.7 grams of HE).

This gun was used on the La7-FNV (approximately 386 deployed durring WWII), commonly refered to as the "3 cannon La-7".

The critical factor of this gun is its very low weight and very high reliability. Jam rates were in the 1:4000 rounds fired catagory and could often be cleared with a recharge (many guns like the Hispano have less than a 50% chance of successfully clearing a jam via gun recharging). The B-20 weighed only 25 kg including mounting hardware. This compares to:

.50 BMG = 30 kg
Hispano II = 50 kg
MG151/20 = 42 kg
MK108 = 44 kg



And none of those weights except the .50 include the mounting hardware, so add about another 20%. And most .50's were mounted in Edgewater recoil mounts and the weights of those are not included (as it is more than just a mount really). The Hispano in particular required a seriously heavy mount as it is not structurally sound on its own.

The B-20 rof was about 800 rpm in the La7 - this was a synchronized installation! Unsynchronized I believe the gun fired at 1150 rpms but I've not found any WWII data to confirm this (post-war it was used in the UBT format in bomber turrets). Muzzel velocity varied from about 770 m/s to about 825 m/s depending on the ammo type, perhaps more in the fixed mounted unsync'd installations. Ammo fit in the same belt links as the 12.7 mm ammo, so belt length was the same, therefore approximately the same number of rounds could be fit in a given gun tray as would fit for a .50 BMG. Eight B-20's could probably be mounted for just a little more cost in weight than six .50's.

So to my thinking, all things considered, the B-20 was the best aircraft gun of WWII. It had enough hitting power to down any target considering its velocity characteristics, RoF, and the number of guns that could be mounted.

As an example, consider an FW190A-8 could have carried 6 of these guns and would have been toting only 75% as much weight as the German armament of 4 x MG151/20's + 2 x MG131's, and it would have had only a little over half as much weight out in the outer guns creating less of an unsprung weight issue (which is bad for roll characteristics and overall manuverability). And the guns would have jammed only about 1/3rd as often as the MG151/20's!

For the weight of 4 Hispano's you could carry at least 10 B-20's! (including the required mounting weight).

=S=

Lunatic

[Gnomey]

Schwarzpanzer. Dunno why I mixed them both I just like them both.

The B20 sound like a pretty nice gun though Lunatic. Good info.

[DerAdlerIstGelandet]

Id go with 8 MG-151's.

[the lancaster kicks ass]

how comes no one's done an armourment for a bomber?? i'm working on one now!

[MacArther]

Thats what I was talking about. 6 .50 cal electric gatling guns, and maybe a .55 in coupled with the gun in the tail.

[Erich]

.................... back for a moment on the WW 2 night fighter arrangement. It was found by all A/F that under the belly was the preference due to the muzzle flash of either mg's or cannon in the nose, the crew being blinded. the Bf 110G-4 when it was still used in 1945 had the upper guns usually fitted with flash retarders.

As for the MK 108 fitted through the hub, yes ! look at the Ta 152H, some of the Bf 109G6/AS, G-10 variants all had lengthened inner barrels

[MacArther]

I've heard that the .50 was effective, but I have also heard that it was not enough. So, would a .50 minigun on a fighter or bomber be enough of an armament. Lets say a figher with 2 .50 miniguns and a bomber with 4 miniguns.

[Glider]

For what its worth I believe that a 0.50 minigun isn't enough for a fighter but is ideal as a defensive weapon on a bomber. The theory is as follows.

A .50 minigun on a fighter would I suspect not be enough because to knock down a heavy bomber you need more punch. It would however be more than enough to shoot down a fighter at short to medium range. A minigun probably has about the same rof as 6 .50 and you needed more firepower than that to take on a B17 type bomber let alone a B29. Using the 1 to 6 ratio, two miniguns would be roughly equal to 4 20mm Hispano cannons which would suffice but I don't believe would be a major improvement on the firpower of a number of WW2 aircraft.

However I do believe that a .50 would be ideal as a defensive weapon on a bomber. The 0.50 was accurate at long range a fact which I think everyone will agree to. A minigun with its massive rof in a compact package, will be able to hit the incoming fighter at a long range.
Even though at long range it might not have the power to shoot the fighter down, as a defensive weapon on a bomber that was less important. The primary role of a defensive weapon is to stop the defending plane being shot down. No attacking plane taking hits at long range is going to keep coming in, it will take evasive action to get out of the line of fire.

[Gnomey]

For what its worth I believe that a 0.50 minigun isn't enough for a fighter but is ideal as a defensive weapon on a bomber. The theory is as follows.

A .50 minigun on a fighter would I suspect not be enough because to knock down a heavy bomber you need more punch. It would however be more than enough to shoot down a fighter at short to medium range. A minigun probably has about the same rof as 6 .50 and you needed more firepower than that to take on a B17 type bomber let alone a B29. Using the 1 to 6 ratio, two miniguns would be roughly equal to 4 20mm Hispano cannons which would suffice but I don't believe would be a major improvement on the firpower of a number of WW2 aircraft.

However I do believe that a .50 would be ideal as a defensive weapon on a bomber. The 0.50 was accurate at long range a fact which I think everyone will agree to. A minigun with its massive rof in a compact package, will be able to hit the incoming fighter at a long range.
Even though at long range it might not have the power to shoot the fighter down, as a defensive weapon on a bomber that was less important. The primary role of a defensive weapon is to stop the defending plane being shot down. No attacking plane taking hits at long range is going to keep coming in, it will take evasive action to get out of the line of fire.

Good points Glider. I agree with you on them all.

[plan_D]

A Fw-190D-9 with a 30mm Aden firing through the hub and a 20mm Vulcan in each wing. Is that enough to bring down a B-17?

[Glider]

If he could catch it with that lot. The 30mm Aden would do it.

[DerAdlerIstGelandet]

Im sure a Fw-190 would catch it.

[Glider]

Carrying 2 Vulcans and an Aden?. Even money on the recoil taking the wings off.

[carpenoctem1689]

Does anyone put thought into ammo carriage on the fighters designed to carry these? mini guns fire FAST, and the ammo supply normally carried would be depleted very, very quickly, making the design effective for about three seconds until the ammo is gone.

[the lancaster kicks ass]

miniguns were suggested for use on american bombers that normally carried several tons of ammo- rate of fire's not a problem!