Aces High Bulletin Board
General Forums => Aces High General Discussion => Topic started by: Wilbus on October 19, 2002, 12:40:46 PM
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I have a quesiton regarding 12.7mm Russian UBS.
I just got the book about Single engine russian fighters aswell as the one about multi engine planes.
They're called "Soviet Combat Aircraft of the Second World War Volume one: Single-Engined fighters" and "Soviet Combat Aircraft of the Second World War Volume two: Twin-engined Fighters, Attack Aircraft and bombers"
Authors are Yefim Gordon and Dmitri Khazanov with Alexander Medved
Here's a snip from the foreword....
Until now, books on Soviet aircraft of the era have relied very much on Western sources and have been lightweight on first-hand information, especially on design origins, production, flight testing and combat experience.
In researching Soviet Combat Aircraft of the Second World War the authors have trawled rich resources of Russian origin, including manufactures, flight test establishments and Soviet air force and naval aviation operational records.
This has produced a wealth of new material, much of which re-writes previously held Western views and at last presents a detailed and authoritative study of this fascinating subject.
Haven't had the chance to read all too much in any of the two volumes yet, what I have read is very impressive though and they make comparisons with some other aircraft aswell.
In the beginning of the two volumes they discuss some armament, and make some comparisons, mostly with the 30 cal Browning, 50 cal Browning and the ShVAK and Brittish Hispano. They also compare the the 7.62mm ShKAS and later Lightweight Ultra ShKAS with the Browning 30 cal. (leightweight Ultra ShKAS had a rate of fire of 2,700 rounds per minute!!)
Ok, here's a snip from that.
To provide an intermediate calibre, the Beresin came into use in 1940. M Ye Beresin quickly developed it as a the UBS for synchronized installations, the UBK for wing mounting and also the UBT for bomber turrets. Though it had the same 12.7mm calibre as the '50-calibre' Browning, it weighed only 47lb (21.4kg) compared with 64lb (29kg), and yet fired projectiles weighing 1.7 ounces (48g) at the rate of 1050 rounds per minute with a muzzle velocity of 2,789 ft/sec (850m/sec), compared with the Brownings 1.1 ounces (33g) projectiles fired at 750 rounds per minute with a muzzle velocity of 2,749ft/sec (838M7sec)
They also say that the ShVAK had about the same Velocity and fired at a rate of 800 rpm. Rounds were smaller and lighter though.
The question I have, the UBS in AH, fire at a rate of about 870 rounds per minute, behing 70 rounds more then the Chart FDutchman posted in my "Mg151 Vs Hispano" thread but being about 200 rounds per minute slower then the information posted in this book. The authors have apparently done some digging in Russian archives and are most likely correct on it.
Finally, to the Question, is the slower RPM in AH (872 rpm) because they are synchronized thus lowering the rate of fire (1050 being 'clean' rate of fire) or is it that HTC has used other sources (meaning Western sources) where the rate of fire has been stated as lower?
Btw, Pyro, when the Yak 3 is added to AH, I might convert to VVS and you'll stop hearing my questioning of the LW ;) *HINT HINT*
The book also say some interesting stuff about the ShVAK, something I didn't know was that the round was lighter, less explosives in it but had about the same velocity, nice to know when I pick up the Yak 9 next time, knowing that it will have the same trajectory as a Hispano! :)
Any answer much appriciated :)
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There was also a thread on the A/V forums a while back, Wil.
(geez, I seem to remember this stuff way too much! :D )
If I remember the specs correctly, without taking account maintenance or reliability issues, the Russian Universal Beresin heavy machine gun is probably the best of all machine guns ever to be mounted on a WWII plane!
They may have had a hard time during the early years of the wr, but heck, the Soviets really do know how to make weapons ;)
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They may have had a hard time during the early years of the wr, but heck, the Soviets really do know how to make weapons
I've always known they were good at small arms (Ak47 being the most obvious) but that they had this good aircraft armaments during WW2 was a complete surprise to me, very impressed :)
After reading some (not much info) about the UBS it does indeed seam to be the very best heavy MG in service during WW2!
I also read that, had they equiped Spitfire Mk I'1 with just five of the ShKAS early version, the spit would have had greater hitting power aswell as more weight of fire per second then the eight Brownings gave it, it would also have saved it 30kg (66lbs) in weight!!
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I have both books and they are excelllent.
Sounds like you dont have Tonys book. It gives full credit for the supremecy of the UB over the M2 browning and the capabilities of the Soviet 20mms
But find a front line fighter with 6 or 8 of the UB machine guns....
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Perhaps it should be noted that 750 rounds/min was the minimum ROF for for Browning .50 and could be increased with little trouble.
J_A_B
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and no reason the same should not apply for the UB ;)
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Or any other gun ;)
No, don't have Tony's book.... Yet :)
Why I ask. What I don't quite get is that the UBS on the Yak in AH fires 870 rounds per minute, did synchronizing really lower the rate of fire with 200?
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Wilbus, yes the lower ROF is due to them being synchronised guns mounted in the engine cowling.
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Well a nice paint job for the Yak 3 would be Normandie Nieman colour ;)
I promise a bottle of gragg$^$^^$ (I hope it's easiest to drink than it's to type ):) if it's done this way ;)
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That Much Verm? Poor guys :)
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Originally posted by Wilbus
That Much Verm? Poor guys :)
As Vermillion said, syncronization lowers the rate of fire.
How much has been a question and it has been (or is still being) discussed on this BBS as well. It is affected by a number of things, one of the most important ones is the RPM of the engine/propellor itself. If I remember correctly, on AH, since it very difficult to calculate this according to the precise RPM of the engine at the given time of firing, the modelling is done to lower it to 90% (?) or so of the unsyncronized rate of fire as a constant factor on the penality for syncronizing. (forgot which thread it was that I read this... it was most likely Gun Synchronization from Aircraft and Vehicles forum)
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Yup, I knew that synchronizing lowered it (pretyt obvious when ya think about it) but I also think that 200 rounds per minute seam alot. The inboard Mg151's on 190's was only lowered by 50 rpm.