Italy was the first major adopter of the Maxim heavy machine gun and had several hundred by 1914 – but wanted to have a domestic design in production as well. The Italian government and military put a lot of resources into the Perino machine gun, but kept it so secret that it was never properly tested and development was very slow. By the time war broke out, the Perino was clearly not ready for field use – and Maxims (along with other foreign designs) were no longer available for commercial sale as production was being taken up by warring nations. This led Italy to adopt a private design of Bethel Revelli in partnership with the FIAT company.
Adopted as the Modello 1914, Revelli’s machine gun was a delayed blowback system with a wedge under mechanical disadvantage holding the bolt closed long enough to safety cycle. Its most unique element was the 50-round mousetrap type box magazine that used 10 independent stacks of 5 rounds each (a 100-round version was also made). This was a very complex magazine to produce, and much more delicate than the other machine gun feed systems in use at the time. The Revelli is also notable for being the only major machine gun of the period to have a circulating water jacket, operated by a small hand-cranked pump on the condensing tank.
The FIAT-Revelli would see service as both and aircraft and ground gun through World War 1, and was updated in 1935 to an air cooled pattern that would serve through World War 2. These guns are very scarce in the United States today, and I am grateful to the collector who owns this one for providing access to it!
1) THE FIAT-REVELLI 1914 DIDN’T USE A DELAYED BLOWBACK SYSTEM. It’s a breechlock short-recoil system. Infact it has a “locking block”.
2) The cammed locking block’s hub doesn’t act by modifying the force, but the time. The more farther back the hub of the locking block is, the more the barrel has to travel back to unlock it.
And the barrel extension isn’t a bolt carrier (it’s rigidly attached to the barrel and intermittently locked to the bolt).
Re. your point #1:
I’d agree with you IF the breech was not resisted on its way back. In finer definition it would be “delayed blowback, short-recoil actuated mechanism” – if my French is correct 🙂
Some may argue even finer and say “retarded” instead of “delayed”, which would be correct too.
Re. your point #2:
I’d say that the slight rise/drop of lock rotation axis has to do with change of resistance therefore timing of breech opening. It alters slightly geometry between concerned surfaces.
Any short recoil locked breech system is resisted in his way back. At least
by the recoil spring, and by the friction of the bullet into the barrel.
This locking piece only rotates instead of rising, or falling, or moving sideways, but it has to move out of the way for the bolt to move indipendently form the barrel, and can do it only if the barrel moves rearward, so the breech is geometrically locked and not simply delayed. It’s not less locked than in a MG42.
A recoiling barrel extentıon wıth a rotatable locking pin fixedly but rotatably mounted in the frame, provided with the locking surface remaining on or behind the vertical radius of that axis pin, never retains its fully locked position with the bolt since, upward contacting distance to go shortening through rotation. For the barrel and bolt remaining in fully locked position, the locking piece and bolt should be on the same moving piece which is the barrel extention or bolt carrier. Revelli designs have bolts slightly separating from barrel during togetherly backward travel and remain in “Retarded Blowback” concept. Eccentric lock piece axis pin, through slight reciprocal movement, adjusts the contact locking surface to or from the vertical of rotating axis to postpone the delaying time but never goes beyond vertical since causing an upward force for a possible malfunction. IMHO…
It only depends on the shape of the front and rear surfaces of the locking block if the distance between the bolt and the barrel remains the same for all the rearward movement, until they are unlocked, or the bolt is free to slightly accelerate in respect to the barrel, so providing to the case a bit of primary extraction, and avoiding the need to lubricate it or fluting the chamber. In any case the bolt is not free to move indipendently from the barrel, it’s geometrically linked to it, and so the breech is locked.
The shape of the rollers in roller locked systems make so that the bolt is even more free to move, but they are roller locked anyway (and they works well with bottleneck cartridges exactly for that slight degree of movement allowed).
You are NOT correct. I advise you to look into one of Chinn’s books, I believe it is volume V.
Also, look at Glisenti 1910 pistol – same idea.
And same locked breech system.
“(…)THE FIAT-REVELLI 1914 DIDN’T USE A DELAYED BLOWBACK SYSTEM. It’s a breechlock short-recoil system. Infact it has a “locking block”.(…)”
Can anybody retrieve manual for this weapon, which will ultimately positively solve dispute to which category it does belong?
I got the manual years ago! Too bad I can’t translate it or upload it here.
http://www.talpo.it/files/mitragliatrice-fiat-mod-14-revelli-1916.pdf
p.16 describes the locking block.
p.35 describes the functioning.
“il blocco di chiusura, spinto in avanti dalla propria molla, si incastra tra la spalletta di appoggio della culatta e l’intaglio inferiore dell’otturatore assicurando la perfetta chiusura all’atto dello sparo” (“the locking block, pushed forward by its own spring, fits between the shoulder supporting the breech and the lower notch of the bolt, ensuring perfect closure when firing”)
“partito il colpo, la pressione dei gas fa rinculare insieme la culatta-canna con l’otturatore i quali, per un breve tratto, rimangono vincolati l’uno all’altro per effetto del blocco di chiusura, finchè questo si ribalta indietro” (“when the shot is fired, the pressure of the gasses causes the breech-barrel to recoil together with the bolt, for a short distance they remain linked each other due to the effect of the locking block, until it tilts back”)
Very interesting magazine. I wonder how bulky it is in comparison to a belt of similar capacity. Probably the use of spring steel for ten separate magazine springs per unit would have been unsupportable if they had made them on the scale that one of the major powers would have required.
“(…)how bulky it is in comparison to a belt of similar capacity”
For experimental 250-round version of said design, see 8th image from top:
http://airwar.ru/weapon/guns/fiat.html
A lovely case of mechanical technology as applied into beginning of 20th century weapon. The “mousetrap feed” is not a bad idea, in my eyes anyway; belt feed is not perfect either. The thing I like the best is the the cocking handle – it is shouting CORNUT! 🙂
The “mousetrap feed” is simply the way to have a 50 rds magazine in an era where a simply staggered 50 rounds magazine would have caused even more problems.
Italians tried a 50 rds staggered magazine in the SIA 1918 then, and infact it caused problems.
I believe it; there is only that much of power from relatively puny 6.5x52mm shot to handle all that load. Not much reserve there.
I don’t think so, Actually the problem automatic weapons have to face is that cartridges have an excess of recoiling power, and it has to be tamed someway to use it to simply feed the weapon.
The problem of the magazine of the SIA 1918 was that it was simply too long and (being top magazine fed) in action it wobbled too much.
You first sentence is non-sensical. Are you saying that any cartridge can freely move 1 ton of mass. Pure nonsense. I advise you to do more study on topic of momentum vs. impulse.
It is nice to be gun fan or collector, but if you want to speak on topic of firearms mechanisms, or any mechanisms you should have grasp of basic mechanics.
@Denny
Since there are not MGs with a ton of mass, and none wants them, your statement has no sense.
The problem of pure blowback systems is exactly that, out of pistol calibers, the weight of the bolt, and so the weight of the gun, tend to become excessive for its intended use, due to the need to contain the recoiling force of the cartridge.
As said, cartridges tend to have an excess of recoiling force, and it has to be tamed someway to use it to simply feed the weapon. To enhance the weight of the bolt is exactly one of those systems.
“(…)only that much of power from relatively puny 6.5x52mm shot to handle all that load. Not much reserve there.”
There existed 6,5/80 machine gun which was Potato Digger adopted for 6,5 x 52 mm cartridge and retaining belt-feed. See 2nd photo from top:
https://it.wikipedia.org/wiki/Colt-Browning_M1895
which (if I understand correctly enough) was used yet in World War II for AA defense of Italian soil.
Now after some search, I found aerial offspring of Modello 1914 – namely La mitraglice Fiat mod. 1914 da aviazone – apparently have belt-fed version, see page 7 of following http://www.armigeridelpiave.it/SELEZIONI/La%20mitragliatrice%20FIAT%20da%20aviazione.pdf
Cornuto ?
Well, it sure looks like fully-locked short recoil to me, assuming the locking wedge doesn’t drop until the bullet has left the barrel. Just a Mauser Broomhandle scaled up to rifle cartridge with striker instead of hammer and a rate adjuster added. (And water-cooling, to be fair.) Even the cocking ears at about the same place. The clever parts are certainly clever — what an amazing magazine! A harmonica gun on steroids. Thank you Mr. M. for showing this to us.
“(…)amazing magazine(…)”
If you are like it, see also magazine loading tool for it – 4th image from top:
http://www.sadefensejournal.com/wp/fiat-revelli-modelo-1914/
Thank you. This fills a gap.
The thing is that surfaces of this “locking wedge” are designed that bolt moves back (and thus also the case out of the chamber) in firing moment,
because if the bolt does not move at all it couldnt actuate that “locking wedge” cam, and you would have manual repeating weapon instead of automatic machine gun.
It’s not the bolt moving relatively to the barrel extension to make the locking wedge rotate, but the rearward movement of the barrel extension relatively to the hub of the locking block.
Not according to Stivens posted y.tube animation, at 1:50
Exactly according to that animation.
Since the rear of the locking block rests on the barrel extension, the locking block can’t rotate if the barrel doesn’t recoil in respect to the hub of the same block, and it rotates only as much as the barrel recoils.
Of course the cam wedge can rotate, as it is (its hub) mounted on the receiver, not bolt carrier/barrel combo.
It rotates down via bolt recoiling backward while simultaniously pressing against carrier surface and thus transferring the momentum. Which is, at the same time, as I stated many times here, moving forwards due to the drag from bullet on rifling.
@ Storm
So, as I said “It’s not the bolt moving relatively to the barrel extension to make the locking wedge rotate, but the rearward movement of the barrel extension relatively to the hub of the locking block”.
There is no way for the locking block to rotate if the barrel extension doesn’t recoil, as the rear surface of the locking block is resting in contact with the barrel extension.
Barrel extension (as you call it), or bolt carrier/barrel combo, hypothetically if you remove in moment of firing bolt and the cam or “locking block” as you incorrectly call it, can not recoil backwards on their own whatsoever, as bullet in rifling is pushing it forward at all times while travelling down the bore. Lookup blowforward slowmotion videos and study what happens there.
It’s a locking block, and it’s what locks the barrel extension, that’s the name, to the bolt.
The locking block can rotate rearward only as long as the barrel recoils. The fact that the barrel is forced to do that (I know how blow forward works, thanks, you can check the forth comment from the top) does not change this fact. And what the MG would do with parts removed is not what it does with the parts in position.
It’s not the bolt moving relatively to the barrel extension to make the locking block rotate, since their relative positions are estabilished by the very same locking block. It’s the rearward movement of the barrel extension relatively to the hub of the locking block to make the locking block rotate.
Revelli invented that lock exactly to simplify the very complex Mauser Broomhandle action (the Broomhandle had been adopted by the Italian Navy in 1899) by using it and some revolver-style flat spring.
https://i8.photobucket.com/albums/a50/NickStan/Glisenti%20Book%208_zpshgn1psmu.jpg
So…an “en-bloc clip” of sorts?
Mike above is correct, in Browning speak that would be a “barrel extension”.
Note that Italy not only an early adopter of the Maxim, but also of its lightened / improved version the Vickers. Buying 892 Vickers 1910-14 (and stocks of both soldiering on, in understandably diminishing numbers throughout WWI – which they entered May 1915 with only 618 serviceable machine guns). WWI inadequate Revelli production (300 x 1915, 5,000? x 1916, 11,300 x 1917 and 14,400 x 1918) and war attrition and losses (notably 3,000 at Caporetto 1917) saw them desperately grabbing every medium machine gun they could get = Colt M1895 (notably used by the Navy), 4,700 x French St Etienne 1917-18 and recycling any captured Schwarzlose (+ only a few British and they 1917-18).
Hi Denny… Chinn’s classificiation especially in “Retarding/Delaying” department, does not fit in or cover existing terminology. He had his own… Besides, there is anoher Spanish pistol “Anitua” before Glisenti… they all share “Delayed Blowback” operating system and famous FN FiveSeven may be accepted as the “Acme” for this concept… “Locked Breech” needs full fastened bolt and barrel during long or short recoiling sequence… Even a slight sepetation like “Revelli” takes the combination out of “Locked” situation… Chinn described this moving barrel and slightly separating bolt as “Retarding”… Today all described in “Delayed” system… IMHO.
Above is the rebly for Denny’s.
Thanks for your attention Strongarm.
I find discussion with Dogwalker unproductive and left it yesterday early. I am on board with You and Storm though. Take care!
You wellcome Denny… You have done the best… Some behave like internet warriors unfortunately…
Not “imho” but its all a fact !
This is just a delayed blowback, although extremely clever in utilizing mass and and counter-reacting forces that happen in the moment a round is fired.
I’m sure Fiat Revelli not the only one water cooled machinegun with handcrank to pump water back into jacket. Soviet M1910/30 Maxim guns in AA configuration had handcrank pump as part of mount. Check M4 quad mount – cone on bottom of the mount is condensing tank, handcrank was installed on top of it or when M4 was used in flatbed trucks cranks was on side of vehicle. Some US AA mount had these as well. But sure, it was not during WW1.
First gun I’ve seen with an extension spring.
Recoil with a short barrel stroke.
https://youtu.be/2SwNqvUZSW8?t=73
No delays.
Unambiguously positive locking.
One (animated) picture is worth a thousand words. Excellent illustration of this gun’s working guts. Thanks for this link.
Revelli’s intention for designing such a construction should be a different case supporting system than C96 patent rights. In fact so slight case extraction during the highest pressure in the barrel remains very much in the safe level and It surely works in practice but when it comes to classification it should not accepted as locked breech.
Today same concept is used for very light and rapid bullet’s auto loading which sufficient remaining gas pressure and gained momentum can not be obtained through locked breech mechanisms. These guns, like FiveSeven, needs simultinaous extraction and case protection during the time when the expelling bullet being in the barrel and this moving barrel with slow separating bolt is the doctor’s order. Again IMHO.
Do not mix with 5-7. There is a delay.
Mod14 – positive locking.
The lever is clamped between the bolt and the frame until it comes out of the cutout in the frame.
At 5-7, the displacement of the bolt relative to the barrel begins simultaneously with the shot.
Therefore, they know how to explode.
Mod14 is a rather original design.
Although far from rational. Problems with extraction due to the absence of a rollback amplifier and accelerated wear of the locking unit.
Perhaps this can be attributed to the lack of experience and the haste with which the work was carried out.
And Revelli must have been a mad scientist. Did he ever think about realistic wear and tear from field usage? I mean, there has GOT to be a better way to create a positive locking system.
Why this system should wear faster than a Browning’s accelerator?
Mind that almost all the surviving WWI guns (where they fired a lot) had been turned to fire the very hot 8mm Breda cartridge without changing anything internally, and the:
FIAT 1926
Brixia 1920
Brixia 1930
Terni 1933
Used the same locking system.
It seems that they didn’t see any particular wear in it.
The system was so simple that it could be scaled down to pistol dimensions. What other WWI MG locking system could do that?
“(…)system was so simple that it could be scaled down to pistol dimensions. What other WWI MG locking system could do that?”
Lewis
https://www.forgottenweapons.com/lewis-gas-operated-pistol-video/
?
Do not mix,… Thanks… But Why?… Any difference between the parts… A two armed lever contacting barrel with shorter arm and slide wiith longer one… All the action being same but FN is delayed and Revelli is true locked… Interesting…
The cleverness of this design is primarily in that it incorporates this bolt carrier-receiver-barrel combo in overall mass retarding equation, via that “locking” inclined surfaces, and in several moments during firing you can add the mass of both two (or actually three parts, bolt, barrel+bolt carrier) as being one big, even more heavy bolt.
This is also why such low rate of fire.
Think of it as a blowback where whole barrel and receiver of a rifle (put into another receiver shell) acted for a short while as one bolt – as I said before, by that “locking” cam – but its not positevely locked as the force of fired case recoiling backwards pushes bolt back more, than the force of spinning bullet pushes barrel-bolt carrier combo forward, add in a cam and thus the delay.
Of course, the first comment mechanical mastermind of great claims forgot (or never knew) that barrel does not travel back by itself in the moment of firing “to unlock the action”, as bullet travelling and spinning down the rifled bore actually always pushes the barrel (and thus the “bolt carrier” directly attached to it in this mg) forward. Yeah, there is case sticking, as glued, to chamber walls and it drags it back, but still, rifling and bullet always wins in this literal tug of war.
However back from the Musgrave pistol discussion claims, this may sound rude, but its obvious what his intellectual-mechanical reach is, inverted to stubborness for defending unjust and unwise claims.
“Any short recoil locked breech system is resisted in his way back. At least
by the recoil spring, and by the friction of the bullet into the barrel.”
DECEMBER 9, 2020 AT 12:50 PM
Fourth comment from the top.
Glancing at the sectional view of MG reveals that, all necessary elements for “Delayed” action presenting there; The Lock piece is “Accelerator” as being mounted on the stationary frame; the Bolt is mounted in the big massed barrel extention which is “Bolt Carrier” and naturally should be “Movable”; Little mased “Bolt” is the first piece getting the impact of recoil force and it transmits this certain amount of momentum to the propped up “Accelerator” and that accelerator transmits whole momentum to the with a slight mechanical disadvantage to the “Bolt Carrier” as trying to give more speed than its mass deceived and since the big amount of this certain amount of momentum being wasted to accerelate the “Bolt Carrier”, there it remains less momentum than it really deceives for the little mass “Bolt” resulting to slow its backward travel… Just a Delayed Action Blowback… IMHO?…
A delayed blowback (lever, roller, radial) works by accelerating the bolt carrier in respect to the bolt face, so exchanging mass (that would be needed in a pure blowback system) for speed since, to accelerate a mass at double the speed, you need four times the energy.
This system locks the bolt to the barrel extension, preventing it to open before the pressure dropped to safe level, via a positive locking (a solid piece of metal that links the bolt to the barrel).
Here however bolt carrier and barrel are the same, moving just a little bit, but not at the same rate as bolt.
Forces that are needed to extract the case are generated while bullet is still moving down the bore, via momentum the that bolt gets and conserves in moment of firing (as case moves back)
Which does not happen when you have locked action, as there is no case backward stretching and moving, or “blowing-back” in locked action, thus no momentum imparted to the bolt.
Indeed, “tenacity worthy of a better application.” LOL
Again.
There is positive locking, with a short rollback of the barrel.
No rollback accelerator.
Therefore the bolt is very heavy. And the frame is relatively light.
The opposite is true, from the right way for this cartridge.
The bolt does not have enough energy (recoil speed) for reliable extraction, so the oiler.
Because the bolt is too heavy and there is no accelerator, it is difficult to “catch” the right moment to disengage the bolt from the frame. Therefore, the “tempo controller”, which is only indirectly, but originally intended to adjust the unlocking time, by changing the friction force in the locking unit.
Then, they tried to bring all this disgrace into a human form, adding a muzzle recoil amplifier, grooves in the chamber and so on.
But since the erroneous ratio of the masses of the bolt to the frame was initially chosen, and there is also no transfer of the remainder of the impulse from the frame to the bolt, plus strong friction on the locking surfaces, everything is pointless.
There isn’t any oiler. The chamber had been fluted when the gun had been rechambered in 8mm Breda without changing anything internally, because evidently, with that much more powerful cartridge, the action dimensioned for the 6.5mm Carcano unlocked when the pressure was still relatively high. The rest of the critics seems more guessing than other.
Ian said there WAS an oiler on 8 mm conversion (either on prototipes or on the very early run) but it was very soon dropped and fluting was added. I cannot positively prove that he is right but since wrong idea about it having an oiler had to sprung out of somewhere I suspect he is right.
So an oiler was tested (in the ’30s, when the gun had been rechambered in the much more powerful 8mm Breda. An oiler was never needed by the 6.5mm Carcano Fiat-Revelli 1914) and dropped in favour of fluting.
Contrary to what Stiven stated, oiling the cartridges, or fluting the chamber, is NOT needed to aid the extraction when there isn’t enough recoiling force to do so (it would be even ridicolous to assume that in this case, since the Fiat-Revelli MG had been fluted only when it was rechambered in a cartridge that had MUCH more recoil than the original one).
It’s needed when the extracion of the cartridge begins when the pressure in the barrel is still relatively high, to avoid that the pressure sticking the walls of the case to the chamber, while the bolt pulling the base of the case out of it, will result in case separation.
It was needed when the Fiat-Revelli MG had been rechambered in the much more powerful 8mm Breda because the new cartridge would have neded a longer locking time to make the pressure drop to safe level, and so a redesign of several internal parts, while the Fiat-revelli 14/35 had always been intended to be a stopgap weapon, until the Breda 37 had been widely manufactured. Fluting the chamber was faster and cheaper for the same result.
Oilers were supposed to prevent torn cases, not make up for lack of recoil power. I could be wrong.
Acceration of bolt carrier gives a tendancy for bolt to hesitate within this moving carrier and if any clearance occurs, bolt carrier separates from the bolt… Frame mounted accelerator, through its contact surface changing from upright to canted, gives this opportunity… This is why delaying elements stated in my comment… May I expect some more thinking before commenting… Thanks.
The way that “hesitation” happens is because the lever-roller-inclined surface is providing resistance to the rearward movement of the bolt face. The resistance is provided by accelerating the bolt carrier in respect to the bolt face, so exchanging mass (of the bolt, that would have been needed, in a pure blowback system, to have the bolt face to move rearward at the same speed) for speed (of the bolt carrier) since, to accelerate a mass (of the bolt carrier) at double the speed, you need four times the energy, and the energy provided by the cartridge is always the same.
So, all the lever-roller-radial delayed blowbacks do, is to allow to have a lighter bolt than a pure blowback system, because a good part of that bolt is accelerated at a faster speed.
All lever assisted delay systems are based over momentum transfer… This momentum taken from fired round is certain and unchangeable… Accelerator causes momentum sharing on different parts of recoilig masses as being rational with their masses and velocity… Revelli design seems rather complicated of converting certain amount of momentum in operating sequence. The bolt is the first part taking that certain amount of momentum and transmits it through leverage to the bolt carrier which being integrated with barrel which being in close contact with bolt as trying to rise the backward speed of each…Through which, since the bolt which with an unfastened carrier with barrel should get less momentum normaly, gets more speed from contacted carrier, taking more momentum than deceived, gains velocity and since contacted carrier giving some more loaded momentum of certain amount to the bolt, it slows and… The bolt in that slowed down carrier continiues its backward travel with more speed than carrier as causing separation from carrier and its integrated barrel… This may be an explanation in scintific and in fact, only the contact surface of lever with bolt as changing from full face upright to backwardly inclined, through rotation on a fixed frame mounted axis pin, causing the contact bolt to travei on its scanned little arc, gives enough separation from the barrel…
Here is not just momentum sharing but at least partial neutralization as the bullet drags the bolt carrier forward while at the same time you have that cam that is “injecting” the bolt momentum backward onto bolt carrier/barrel combo.
Revelli design is a simple short recoil breechlock where the block that links the bolt with the barrel, instead of rising, falling, or moving sideways, rotates out of the way, to unlock the bolt form the barrel.
While it’s possible to shape the locking block so that while it’s rotating, the space it fills between the face of the block (in contact with the bolt) and the back of the block (in contact with the barrel’s extension) remains the same, and wile that had been partly done ( https://youtu.be/wmymjvYZEps?t=888 the block being tangent to the hub instead of radial to it makes so that, from the point of view of the bolt-barrel assembly, it partly falls instead of simply rotating back) that had not been done completely (and so a slight movement of the bolt in respect to the barrel had been allowed) because non only that would have been more complex to design and manufacture, but, other than being totally useless, it would have been detrtimental.
Infact pure short recoil actions and long high-pressure bottleneck cartridges don’t get along very well. The bolt and barrel being linked until the barrel stops and the bolt keeps on recoiling makes so that the cartridge is violently snatched out of the barrel, instantly passing from “0” to max speed, and that’s very harsh on the brass. The more harsh the more brass surface there is in contact with the chamber.
That’s why the Breda 30, being a pure short recoil action, needed an oiler.
Any successful high-pressure bottleneck cartridge short recoil action incorporates a system for the bolt and the barrel starting to separate, and so the extraction of the cartridge starting, before the barrel stops.
For the Revelli system, that’s assured by the shape of the locking block.
And that’s why the Terni 1933, that used the Revelli action, in a “Breda 30 style” LMG, didn’t need an oiler.
The more I look at it, more is obvious that this bolt carrier/barrel blow forward is crucial for forcing it onto the cam, which at the same rotates downward on a surface, pushed back by a bolt that blowbacks – partial force neutralization system – without it, it will not work, thats why its so clever.
As I said, cam is independent of these other parts, being on receiver, its just its distance could be sligthly adjusted.
You’ve got enough clarification from replys here, in how it actually works.
Oiler or its effect on brass (if any) is completely irrelevant to this discussion and method of operation.
The blow forward is no crucial for this system. Since the Bolt is pushed rearward by the recoil, and it pushes the locking block, it would only need the inertia of the barrel to force the three pieces against each other during the rearward movement, that’s all that is needed for it to work.
In practice, it will work even overboring the barrel.
I actually had to give a lot of clarifications on how it works.
I’m sorry you don’t understand the relevance of the arguments. Maybe you sould read them more slowly.
“Revelli had taken out a patent in
1908 for the gun’s mechanism, which is seen described so often as a retarded-blowback mechanism,in which the barrel recoils for a short distance before the bolt moves away from
the breech.
In point of fact, however, the mechanism is really a combination or short recoil and blow-back. Locking by wedge is so slight that the gun is not a locked-breech weapon in
the true sense of the word, but is rather a hesitation pattern blowback. ”
(excerpt from this article by Bill Ruxton, from 1988. : http://www.baronerosso.it › forumPDF
The Fiat-Revelli Machine Gun – Barone Rosso )
How can be “slight” the lockling if the barrel and bolt are linked by a solid piece of metal?
It’s no different than the locking block of a Browning 1917, and completely different from an hesitation lock.
Oh, I read the article. it propales the tale of the individually lubricated cartridges too. It’s quite probable that Bill Ruxton wrote that article without seeing the actual gun (infact there are only old pictures of it), reading the manual, or understanding the working mechanism at all.
Yeah, quite probable gun researchers were wrong all this time and you figured it out finally after 110 years.
The respected commenters have abandoned and left the discussion, so you’ll have to carry on at your own convenience.
Not “gun searchers”. Bill Ruxton, the author of the article you used as a source IS wrong about the necessity of individually lubricated cartridges in the FIAT-Revelli 1914, so it’s safe to say that the author is uninformed about the object he’s writing about.
The text books which I have, such as “Military Small Arms of the 20th Century” by Weeks and Hogg, refer to the Fiat-Revelli as delayed blowback. But to my mind, if the barrel recoils with the bolt under some form of locking, it is a recoil system, not a blowback system.
Thus, an MG42 is a recoil operated gun, as the barrel recoils with the bolt, but a G3 is delayed blowback, because the barrel is fixed, even though both use a similar roller locking, or as some prefer, delay system.
The Fiat-Revelli has a poor reputation, but I do not know if it was deserved or not. The bolt extension with the charging handle on it is odd by our standards, but Maxim type guns also have the charging handle swinging around close the the firer’s right hand, and no-one seems to think it dangerous. Likewise, the 50 round mousetrap magazine seems strange, but it is certainly more compact and easier to handle than a 250 round cloth belt.
Although it is unlikely to happen, I would love to see a firepower demonstration between a Fiat-Revelli and a Maxim or Vickers gun, just to see how they compare, but the guns are very old now, so one can but hope.
I hope you are not going to argue that the Japanese Type 11, 92, 96 cartridges were lubricated the same for the correct operation of the bolt delay-recoil? 😉
The built-in oiler appeared later.
On mod 1914, the cartridges were lubricated by hand before being installed in the cassette.
http://www.sadefensejournal.com/wp/fiat-revelli-modelo-1914/
https://comandosupremo.com/fiat-revelli-modello-1935/
Yes, case lubrication (as well as Rivelli grooves) are used both to prevent brass breakage and to facilitate extraction.
http://www.gotavapen.se/gota/artiklar/utv_ksp58/ksp14/schwarzlose.htm
But, if cases are brake, then they do it constantly, lubrication only reduces the number of such cases.
https://www.thehighroad.org/index.php?threads/oiled-chamber-difficult-to-extract-why.699243/
I have not seen any mention of complaints about case breakage in these machine guns.
And if not…
then it was not.
https://www.thehighroad.org/index.php?threads/machine-gun-oiler.838074/
I hope you are not going to argue that the Japanese machine guns cartridges were lubricated the same for the correct operation of the bolt delay-recoil? 😉
The built-in oiler appeared later.
On mod 1914, the cartridges were lubricated by hand before being installed in the cassette.
http://www.sadefensejournal.com/wp/fiat-revelli-modelo-1914/
https://comandosupremo.com/fiat-revelli-modello-1935/
Yes, case lubrication (as well as Rivelli grooves) are used both to prevent brass breakage and to facilitate extraction.
http://www.gotavapen.se/gota/artiklar/utv_ksp58/ksp14/schwarzlose.htm
But, if cases are brake, then they do it constantly, lubrication only reduces the number of such cases.
https://www.thehighroad.org/index.php?threads/oiled-chamber-difficult-to-extract-why.699243/
https://www.thehighroad.org/index.php?threads/machine-gun-oiler.838074/
I have not seen any mention of complaints about case breakage in these machine guns.
And if not…
then it was not.
And regarding the displacement of the brass before unlocking.
Even if it is there, for the entire time of the shot, the bolt (according to the rule of levers) can be displaced by such an insignificant amount (less than the usual gap for rifle cartridges) that you can ignore it.
Patent
https://patents.google.com/patent/US1073709A/en?oq=US1073709