Nodeo-Franvier
Airman 1st Class
- 124
- Jul 13, 2020
What could be considered best synchronizable heavy machine gun of the war?
Best synchronizable heavy machine gun of the war?
- Thread starter Nodeo-Franvier
- Start date
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The Berezin UBS (the synchronisable version of the Berezin UB) comes of with high marks compared to the 50 calibre Browning AN/M2 since it fired an equally powerful cartridge but weighed 60% as much (25kg versus 40kg) and fired at 20%-25% greater rate. Post war the US AN/M3 fired faster than the Berezin UB by 15% and was used on Korean War P51 and Sabres. It barely missed the war.
The Berizin UB dropped form 1050 rpm to 800 when synchronised, a drop of 25% typical of mechanical-hydraulic sonic systems. The Brownings used on early P40 used a sonic hydraulic system and lost a similar percentage. It was academic, the US had big fighters that could carry a little extra weight, abandoned engine mounts when multiple guns came in to use and didn't need to destroy heavy bombers.
The Germans used electrical primers instead of percussion so they only lost 9% in rate of fire when synchronising guns.
The 13.2mm MG131 the used had less fire power and a little less range than the Browning or Berezin but it weighed on 13kg, half that of the Berezin but still had 3x the destructive power of a rifle caliber. It could thus be mounted where the bigger weapons couldnt fit. Range was about 400m but could be effective to 600m.
The MG151 "canon" was a machine gun by Luftwaffe definition whether 20mm or 15mm and I would regard as winners when synchronised due to to the electrical interruption system.
The MG213 20mm revolving breech gun could be synchronised, it used a far more powerful cartridge than the MG151 but just missed service. A Fw 190D squadron was assigned to combat test them.
afaik the loss of rate of fire is not a fixed %, it's depend from the propeller rpm and so from the engines rpm
this is from my media, my alone media, is for a Breda Safat in a MC.202, i'm sure i've cited the italian forum i get it the first time i posted here, now i'm not sure what is the forum, EDIT now i'm sure is from 150gct.it forum
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SuperAereo
Airman
- 32
- Jun 23, 2009
150.gct, I believe...
highly probable, after adjusted the image i see the symbol i remembered yes was the 150gct.it forum
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Shortround6
Major General
for the 2nd part, the Gladiator and Avia 534 managed to get the ammo near the center of gravity. Most planes with engines in the front seemed to do OK as the ammunition boxes were behind the engine and many times the gun breeches intruded into the cockpit.
I am not sure the number of blades has a lot to do with it. P-40 Prop turned 1500rpm at full throttle. Guns fired at at around 500rpm (if you were lucky) Prop made about 3 full turns between times the gun fired. Finnish Buffalos were even worse. Engine had no reduction gear. Prop was turning 2100-2200rpm.
On the Italian C. 200 and G.50 the prop was doing about 1600rpm.
On V-12s the synchronizer gear was often driven by the camshafts. It may be that they fired the gun every so any revolutions of the engine/prop.
P-39 Expert
Non-Expert
Agree. Three or four blade prop made no difference. The only AAF fighter with synchronized guns used in quantity was the P-39 and it had both three and four blade props. Big brother P-63 had four blade prop.
Always wondered, did the Russian guns really have that much greater rate of fire? Seems fantastic.
Shortround6
Major General
A lot depends on the other aspects of the gun design.
When the US tried to push the M2 .50 up to 1200rpm they imposed some rather severe restrictions on the project. like the number of broken parts and jams per 1000 rounds fired. They also wanted it done as a modification kit that could be fitted to existing guns in the field but had to give up on that. The M2 and high rate of fire M3 are rebuildable to a considerable extent. The US may have been able to get a high rate of fire .50 into action over a year sooner if they had been willing to accept a bit less reliability. However unreliability had been a major criticism in 1942 of both wing guns and early turret guns.
The Russians decided to go for high rates of fire with essential disposable guns. The parts are more subject to breakage and the entire gun may get scrapped after just a few thousand rounds, but it does make for a light, high cycle rate gun.
I believe the Molins company of Great Britian got a Hispano gun up to 1000rpm but the reliability/durability was a bit less than what was wanted. This is the company that designed and built the feed system for the 57mm gun in the Mosquito and in large numbers of motor gun boats.
When the US tried to push the M2 .50 up to 1200rpm they imposed some rather severe restrictions on the project. like the number of broken parts and jams per 1000 rounds fired. They also wanted it done as a modification kit that could be fitted to existing guns in the field but had to give up on that. The M2 and high rate of fire M3 are rebuildable to a considerable extent. The US may have been able to get a high rate of fire .50 into action over a year sooner if they had been willing to accept a bit less reliability. However unreliability had been a major criticism in 1942 of both wing guns and early turret guns.
The Russians decided to go for high rates of fire with essential disposable guns. The parts are more subject to breakage and the entire gun may get scrapped after just a few thousand rounds, but it does make for a light, high cycle rate gun.
I believe the Molins company of Great Britian got a Hispano gun up to 1000rpm but the reliability/durability was a bit less than what was wanted. This is the company that designed and built the feed system for the 57mm gun in the Mosquito and in large numbers of motor gun boats.
P-39 Expert
Non-Expert
Thanks. Disposable guns, makes sense.
Do we know how many rounds will the/any Soviet gun sustain before breaking?
Do you have a source for this?
Shortround6
Major General
Somewhere I read that the 12.7mm guns might be good for around 2500 rounds. Don't know it it is true, but that would be good for over 10 missions in which not only did the pilot fire the guns but emptied the ammunition boxes. I believe it is in one of Anthony Williams books.
Please remember that the aircraft guns only have the ammunition in common with the DShK ground machine gun which certainly earned a reputation for reliability/durability.
Please remember that the aircraft guns only have the ammunition in common with the DShK ground machine gun which certainly earned a reputation for reliability/durability.
P-39 Expert
Non-Expert
So the aircraft HMGs had a higher rate of fire and lower reliability than the ground version? Am I understanding this correctly? This whole Russian gun ROF thing has always intrigued me.
- Thread starter
- #16
Nodeo-Franvier
Airman 1st Class
- 124
- Jul 13, 2020
Anyone know why Ho-103 perform so poorly?
swampyankee
Chief Master Sergeant
- 3,991
- Jun 25, 2013
It's not reliability; it's service life. Aircraft machine guns are used to fire a few hundred rounds per mission, with the number of likely missions being fairly small. At a loss rate of 0.5% per sortie, 50% of the aircraft are gone by 140 sorties. A life much past 10,000 rounds is superfluous.
According to this article, the service life of Berezin 12.7 mm was 10,000 to 12,000 rounds during the initial tests in 1941.
6 machine guns were tested on I-16 and I-153. 36,870 rounds in the air at the altitudes from 1km to 9km and 11, 416 at the ground.
1,470 rounds per gun until the service (cleaning, lubricating).
Универсальный пулемёт Березина отмечает юбилей
Shortround6
Major General
Thank you, I will stand corrected on this. 
