Even if you don’t like firearms, the design behind some of these weapons is great! Very interesting video, please don’t stop making these types of videos. You are very knowledgeable.
@@lanchanoinguyen2914 I disagree: i don't really care about motorbikes but i do appreciate the beauty and skill going into manufacturing it's components. The same can apply to firearms
I love to think about firearms from a design and manufacturability standpoint. I spent my college career studying manufacturing and material science, and my career has been focused on it as well. I’m not much of a “gun nut” but I they are great examples of design for manufacturability; wether it’s Germany’s last ditch weapons of defense, or a precision marksman rifle, all firearms are designed in a time and place that forced their designers to consider many variables... materials, manufacturing methods, cost, speed, user... The clever solutions and ingenuity captured within firearms can teach us plenty.
100% of my viewership of Forgotten Weapons and InRange is based on academic interest in firearm design, manufacture, and operation. I couldn't hit a lake if I was standing on the bottom.
It's really easy: roller locked: 2 pieces moving together for a bit, then only one piece continues roller delayed: 1 large piece moving for a bit, then picks up the second one
I always found it interesting that the German army its armament research organisation, the Heereswaffenamt, for such a long time was opposed to drilling a hole in the barrel for a gas port. Then they finally relented after the problems with the G41. Subsequently Mauser got its hands on the G43 and they started experimenting with a better bolt design for that rifle and eventually came up with this system that removes the need for a gas port or a hole in the barrel. For those interested, that first rifle would be the Gerät 03. Ian has a video on that one as well. ruclips.net/video/g3GJAPgz23c/видео.html Same with the development of the roller delayed blowback for the Gerät 06H. ruclips.net/video/WEPwmYcCPFs/видео.html
I love this series! I have learned a lot about firearms in the past year/years but roller-locked and roller-delayed were still a mystery to me. The best gun channel on RUclips, keep it up.
The important piece of the system is the angles of the ramps in the trunnion. Both the ramp angle and locking piece angle in conjunction with the rollers work to put the bolt head at a mechanical disadvantage to the bolt carrier. This is a multiplicative effect on the greater inertial force to get the carrier moving, and contributes to the delay.
4 years late, but this comment just explained what was missing. When he pinches the rollers together, it wasn't explained how that happens, but your explanation fills the gap. Thanks!
I have seen many of Ian's videos, and this is the first time I don't feel he has done a stellar job explaining how a weapon works. For start: 0:42 - wouldn't that make it a roller-locked (instead of roller-delayed) weapon? 1:15 - what makes "locking" piece to move backward? Is it inward movement of the rollers, acting on angled surfaces pointed out at 0:33? If so, what causes rollers to move inward? Is it backward movement of bolt head, something we were told can not happen at 1:06? Am I missing something here? 🤔
I'm having the same confusion. I've looked at several videos on how roller delayed systems work and so far none of them have explained it it fully.
3 года назад+2
The Action is absolutely fantastic, as it allows high velocity of the projectile by taking full advantage of the pressure of the gases. You do not need an auxiliary piston that makes you lose energy. The only flaw is the extreme stress on the rollers and the accumulated dirt. That is why the rate of fire and the projectile's exit speed are extremely high. The recoil is light and the accuracy very good. The gun is easy to manufacture, inexpensive and has small dimensions. When I shot an HK-33 I realized that if it weren't for the dirt it would be the perfect weapon.
Concept of Reflected Inertia... The lever ratio explanation is true, and the second half of the explanation really makes the concept of reflected inertia make sense. The lever ratio effectively multiplies the inertia of the heavy mass of the bolt carrier. The internal ballistic equations follow the model of a blowback design, except the mass has been multiplied by the lever ratio. The reflected inertia is then used as the mass in the blowback calculations. There are a lot more to the details to make a roller delayed blowback design work well. The devil is always in the details. The lever ratio uses the principle of reflected inertia as part of a blowback design. The engineers at the arsenal taught us how the HK designs really worked, and the HK trainers always were left holding the bag. That is why the HK manuals and even the HK engineering information are so poor. It was pretty cool to be there when the engineers asked questions. The HK myths were busted.
It is interesting to see those small details being explained. One reason I took interest the the PTR-32 was because caleaning was quick, and that was especially important, given how dirty 7.62x39 ammo can be.
Two things: 1 - When Ian first began speaking I thought he was doing his best imitation of "The LockPickingLawyer" and then 2 - I was just SURE he was going to use the CZ-52 as an example of one of the few pistol designs that use the roller lock design! As always.... great video!!! ;^)
Good one! It does annoy me when terminology is misleading to the neophyte: these firearm "delay" systems actually don't have a true delay, ie, one where no movement starts until after some 'dead time'. They're all based around using mechanical disadvantage to temporarily make a moving part appear inertially 'heavier', temporarily, in order to buy time (the 'delay'). They all also suffer with high case pressures to ammo sensitivity, because there is still that movement required to transmit the energy. This works because movement splits equally by conservation of momentum (speed times force), but *energy* goes as 1/2*mass*velocity*velocity (or really, half of momentum times speed). (except for gas delay -- those are about reducing the effective area of the bolt face, by presenting another face attached to the bolt facing the other way to 'subtract' it from the effective area causing the blowback. Anyway, just wanted to point out that confusing terminology annoyance -- no 'delay' system actually has a true 'dead time' delay in it, only 'locking' systems do that. And that's why they all have trouble with increasing chamber pressure, and require fluted chambers or lubricated/extra precise case ammo etc etc for reliable operation.
This is exactly the explanation I was looking for. I simply could not wrap my brain around the written description in my course textbook. Thank you, Sir.
I love these videos from you. Not being able to aquire any guns in my country easily your short explanations make it easier to appreciate the operation of the guns you showcase 👍
Hey Ian, I’m really new to firearms and am unable to own one in Arizona where I live because I am a marijuana patient. I can’t have my own fun so I live vicariously through your channel. Thanks for these smaller breakdown videos, I will hear you say things like “well this is an open bolt where this is a roller delayed” and it’s taken me awhile but I’m starting to understand firearms as more than just complicated tubes that make bullet go zoom
A roller locked delayed blowback gun that that you proably already know about and have stumbled upon it from time to time, the CZ 52. Very underrated in my opinion and I honestly think that it is actually a really cool looking firearm
Tilting bolts can also be used for Delayed Blowback as well. But the closest thing we got to it is the Rudd Carbine. The problem is, the bolt is designed incorrectly. The locking surface should be straight. Not on an angle. And the carrier should have a few inches of travel, before it actually unlocks. That's basically how Delayed Blowback works. Inertia is what replaces a conventional Gas Piston.
i assume because of the cartridge MP5 use, its only a "pistol" round and can use sub sonic one so it have way less chamber pressure than rifle round like 556 or even 762.
@@jantschierschky3461 It's not really the recoil, it's high residual pressure, making the system run way faster than it's supposed to and it running way way dirtier than normal.
@@prd6617 Dunno about using the 3 lug adapter, but on the SD, the effective barrel length ends up being only a couple of inches. After that it's ported into the silencer, so it never gets a chance to build a whole lot of pressure in the first place.
Thank you for this channel! can you do a series on different sorts of lockup/delay mechanisms? I've heard of 'radial delayed blowback' and such ar15's now, and as an aspiring gun designer I'd like to compare notes of the survey of actions out there that I've done with the surveys others have done, and it's hard to do that if you're not already established in the gun industry and in contact with many people in it- so having a channel like this is invaluable. Keep up the good work!
@@faithismyskyfall Its a good rifle. Accurate, and in a decent caliber. I felt like a wimp being retrained in 5.56 M4 carabines. Not knocking the M4. 7.62 is just a better caliber for me.
Fun story. Some years back, a dumba** behind the gun counter at a local outdoors store tried to sell my dad a G3 clone saying it was gas operated. Thanks to the one gun book 12 year old me owned, I informed him (my dad, not the dumba**) that it used, in fact, something called roller-delayed blowback. The book was very lacking in details, just providing basic info on a wide variety of guns. But even that little bit of good information can make a huge difference in how informed of a purchase you make.
My Sig510's / STGW57's have roller delay blowback. I always had the feeling the point of this is not delay (as it still opens immediately). The roller with the little ramps however compress the main spring for lets say 1 cm, but the bolthead only moves 0.5 cm. So from the bolthead's point of view the main spring is much stiffer the first bit of travel, due to the roller mechanism. This way a lot of recoil is absorbed in the first bit of travel, more than without the roller mechanism.
Agora a pouco descobri que o HK G33 e o HK G3 funcionam com esse sistema, fiquei impressionado, e comecei a buscar como isso funciona porque é muito diferente do que eu imaginava. Eu achava que aquele tubo acima do cano da arma era um sistema de gás, e que por isso esse era o sistema dessa arma. Obrigado pela legenda em português 🇧🇷✌️
I wish you'd expanded on those advantages and disadvantages. I get why it might be dirtier than a typical blowback based on the design, but why doesn't it work well with suppressors? The MP5 and its ilk all use suppressors. And if it works well with cheaper stamped-sheet receivers, why is the MP5 so expensive while the cheaper UMP doesn't use it?
There's one important piece of information missing: the rollers act as a lever and thus they accelerate the mass faster than the piece behind the cartridge. This reduces the weight of the mass needed by about 4x! Otherwise, you could just use a normal blowback for a rifle as done with some tripod machine guns...
Very true. You really understand how the system works. Have you ever tuned these actions for use with low power ammo? People that understand what you mentioned get asked to fix MP5 and clones all the time.
@@johnphillips222 LOL. I´ve never handled one in my life! In fact, I´m not legally able to handle firearms. I bet barrel length and muzzle break will need to be considered as well. In the case of WWII, it was easy to implement the design, but the ammunition quality would almost guarantee malfunctions. I guess that´s one of the reasons why the MG42 was built slightly differently. For one it used the barrel as additional mass and had a recoil booster. This should make the accuracy and recoil worse, but still, it was a damn good LMG at its time. I bet these changes were because of the ammunition quality. On the other hand, the allies failed to copy the design for their own ammunition indicating that the adjustments are very subtle but essential...
Jeah in German the locking system of our G3 is called " Übersetzter Massenverschluß " The direct translation would be " weight operated locking system with transfer ratio "
@@heikopanzlaff3789 Yes. I'd translate it with leveraged inertia, but I'm not certain about _Verschluss_ as that word seems to be a bit broader in meaning than locking. A cork in a bottle could also be a _Verschluss_ and the operating system is not truly locked...
It's about the inertia of the bolt carrier. The idea is to let the powder charge finish burning (and the bullet to get all the way out the barrel) before the bolt starts moving back. But sure, another video wouldn't hurt. ;>)
After almost a half hour spent on watching this video, and a couple other videos on it, AND reading up on it, I finally had that eureka moment on how to properly mentally visualize and understand how a roller delayed blowback system actually works. My gosh, that took me way too long! Hahahahaha! I had to put it into much simpler words for myself in order to actually understand it. Maybe I just need to sleep lol.
while im serving in military i used hk33 as a primary gun it was little bro of g3 but i still couldnt get the how does it works. after this video i still dont get it
Nice! So good to have easily understood videos showing the difference between roller locked and roller delayed blowback guns. Mixing the terminology has sadly become the norm.
An argument can be made that roller delayed could also be roller locked. (like how all bourbons are whiskeys, but not all whiskeys are bourbons) During firing in a roller delayed blow back, the rollers do technically mechanically lock the bolt to the trunnion/barrel...
Yes and no. So yes, it is, but it's really the same as the HK91 action but with more infrastructure around it. Dedicated machine gun implementations of the system (MG42V/MG45, SIG 710) didn't take off.
@@ForgottenWeapons Fair enough. I understand that it was an off-shoot adaptation of the G3, and not designed as a blank page ground up general purpose machinegun. I just thought that since it was intended to and did fill the roll as a GPMG, it counts.
And SRM Arms managed to make it work in a shotgun. Even H&K complimented them saying they figured out something they've been trying to get to work for decades and couldn't.
If there isn’t any gas system, how does the locking surface move back? Since the rollers are locked in place already, where is the force which moves the bolt carrier back coming from?
for some unclear reasons, roller-delayed blowback is my favorite firearm mechanism. Probably because of watching HK slap in the first shooter game I've ever played
Based on your description, it sounds like the difference between roller delay and roller locking is one of degree. Both are gas actuated. Roller locking sounds like it travels further up onto the flat and in doing creates a longer period of delay, or locking for the entire firing impulse?? While roller delay, since it is parked on the angle is starting to retract immediately and so isn't fully locked. Am I tracking correctly? I am thinking that perhaps I am missed something?
They're not gas actuated, unless you count the gas that's inside the cartridge case. A roller delayed system is never fully locked, the rollers and the angled locking piece merely act as increased leverage so it takes more force to accellerate the bolt rearwards than its mass alone would suggest. In a roller locked system, the bolt is fully locked and needs to be unlocked by some other force than blowback from the pressure inside the cartridge case. Most commonly this is done with a short recoil system, where the barrel and bolt move rearwards together for a bit until the rollers are disengaged by a cam or somesuch. There's no reason why you couldn't build a gas operated roller locked mechanism, though I cannot think of any.
In a short recoil system, the slide+barrel start moving immediately (although locked together), and it's the combined mass+recoil spring that defines when they hit the cam and unlock. Which defines the pressure at unlocking. In a roller delayed system, the slide (or bolt carrier) start moving immediately (while the bolt is still locked with the barrel), and it's the mass of the bolt carrier+recoil spring that defines when the rollers retract and the bolt unlocks. Which defines the pressure at unlocking. In short, I fail to see principal difference between short recoil and roller-delayed blow-back. Of course, rifles rarely use short recoil, which seems to suggest that both systems are insufficient for rifle cartridges. But why is it not used more in pistols? Seems like a win - the barrel can be fixed, which increases precision and decreases manufacturing costs (if you've ever fitted a proper "oversized" barrel you know why).
maybe because, while in a rifle you naturally have a bolt carrier and a separate bolt, in pistols you'd have to introduce an additional part? But then Beretta have their moving locking block, for example.
While rather simple from the operator's point of view, as compared to the gas-operated system, this design is quite difficult and expensive to produce, and requires a very precise manufacturing. Also very tough = expensive materials must be used for the rollers and other locking parts, because they are under very high stresses. That, IMO, is why it was never used by almost anyone else other than HK (at least, AFAIK). I always wondered why they just didn't use lever-delayed blowback, like the Kiraly system, achieving the 4-to-1 transmission ratio would be quite trivial with a simple lever (of course, probably there were some reasons for that; probably, the use of a stamped receiver is the reason - the rollers allowed to use a small barrel extension for locking, and the rest of the weapon could be made from sheet steel; lever-delayed blowback seems to require a more substantial receiver - AFAIR even the FAMAS uses at least partially milled receiver).
It's where they machine some small slots down the side of the case neck to borrow some gas to push against the case and improve primary extraction. Once the case is moving, it's fine. My Tokarev SVT40 has a fluted chamber, as do pretty much every HK firearm.
So I'm guessing if there isn't a gap between the bolt and a carrier like the specs ask for the rifle will rail to cycle since theres no room for movement of the bolt head post firing?
So if one took a roller delayed rifle and welded it to an immovable stand, it would not cycle? Put another way, it needs the recoil of the rifle to move the bolt within the rifle and make it unlock?
it looks like the rollers would push the bolt rearward, not hold it in place. Wouldnt there need to be something ahead of the ramps on the bolt for the roller to lock on to it in order for the bolt to be held in place?
He's answered this question various times, and the answer is always "No." He's a historian, not an engineer. He's also waxed poetic about the futility of trying to become a firearms designer in these modern times of highly developed and successful firearms. I agree with him. It's not impossible, but the days of "Hey! I've got a great new idea!" are essentially over. Today the route to firearms design lies in learning to be a quality machinist, getting a job with a manufacturer, and then convincing that manufacturer that you have an idea worth exploring. The last one is actually the hardest.
@@Commissioner. Maybe you should include piezoelectric components to complement your schizophrenic effects. (I just like how those words sound together.)
want to ask, what was the rifle with hollow chamber in the bolt carrier, half filled of something like sand or metal powder? trying to google it but not successfully at all.. seen pictures of that year ago or so.. any ideas what rifle it was?
Ian, not sure if you read these comments.. but i need gun jesus on an issue with a roller lock i just bought. Bought a c93, when it came in the charging handle was seized, knocked it loose but it's been sticky and harder than normal to pull back (my ptr91 is vastly easier). I took it to the range, it'll load just fine, but when it fires it won't eject the spent brass. It'll stay on the bolt head and try to rechamber another round with it there. I've tried fb groups and no one knows anything about this. Any help would be greatly appreciated!
i don't understand how the bolt goes backwards since there's no gas tube is it the gas that moves the entire bolt group back inside the chamber that causes the whole thing to go back before it's pushed forward in place by the spring ?
Did this channel do a video on the mccrudden light machine rifle of Australian origin? I saw a pic of the gun the other day and thought it must have a cool story behind it, or at least an interesting mechanism.
![Felix "Unfair" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/Oswujxm2Ag0/mqdefault.jpg)
Even if you don’t like firearms, the design behind some of these weapons is great! Very interesting video, please don’t stop making these types of videos. You are very knowledgeable.
you can't see the beauty of firearm if you don't like them.
@@lanchanoinguyen2914
I disagree: i don't really care about motorbikes but i do appreciate the beauty and skill going into manufacturing it's components. The same can apply to firearms
I love to think about firearms from a design and manufacturability standpoint.
I spent my college career studying manufacturing and material science, and my career has been focused on it as well. I’m not much of a “gun nut” but I they are great examples of design for manufacturability; wether it’s Germany’s last ditch weapons of defense, or a precision marksman rifle, all firearms are designed in a time and place that forced their designers to consider many variables... materials, manufacturing methods, cost, speed, user...
The clever solutions and ingenuity captured within firearms can teach us plenty.
100% of my viewership of Forgotten Weapons and InRange is based on academic interest in firearm design, manufacture, and operation. I couldn't hit a lake if I was standing on the bottom.
@@michaelince7998 hate to say it but it sounds like you kinda like firearms and are just scared they may like you back uwu
I had always kind of wondered what the difference between a roller locked and a roller delayed system was. Thanks for the input.
It's really easy:
roller locked: 2 pieces moving together for a bit, then only one piece continues
roller delayed: 1 large piece moving for a bit, then picks up the second one
@@phileas007 That's roller locked short recoil. You could make a roller-locked gas operated gun if you wanted
@@MBkufel agree, but then you'd probably use flappers instead :)
Last time I was that early, Gerät 06 was still fully locking.
I'm just here to pretend I know what's going on.
Just do it like you know it.
Same for me. ;w;
It's not difficult. The rollers have to overcome the resistance of the angled recesses, delaying the opening of the bolt.
Well done then.
@@skepticalbadger uh... Gesundheit?
Absolutely love these fascinating looks into how the various mechanical systems work. Keep it up.
The pistol footage was from the Korth PRS, 7:20 timestamp for the bcg. Beautiful piece of engineering :-)
@@TheRealColBosch yw mate :-)
I always found it interesting that the German army its armament research organisation, the Heereswaffenamt, for such a long time was opposed to drilling a hole in the barrel for a gas port. Then they finally relented after the problems with the G41. Subsequently Mauser got its hands on the G43 and they started experimenting with a better bolt design for that rifle and eventually came up with this system that removes the need for a gas port or a hole in the barrel.
For those interested, that first rifle would be the Gerät 03. Ian has a video on that one as well.
ruclips.net/video/g3GJAPgz23c/видео.html
Same with the development of the roller delayed blowback for the Gerät 06H.
ruclips.net/video/WEPwmYcCPFs/видео.html
A whole history lesson crammed into a comment 👏 bravo
I love this series! I have learned a lot about firearms in the past year/years but roller-locked and roller-delayed were still a mystery to me. The best gun channel on RUclips, keep it up.
The important piece of the system is the angles of the ramps in the trunnion. Both the ramp angle and locking piece angle in conjunction with the rollers work to put the bolt head at a mechanical disadvantage to the bolt carrier. This is a multiplicative effect on the greater inertial force to get the carrier moving, and contributes to the delay.
4 years late, but this comment just explained what was missing. When he pinches the rollers together, it wasn't explained how that happens, but your explanation fills the gap. Thanks!
I have seen many of Ian's videos, and this is the first time I don't feel he has done a stellar job explaining how a weapon works.
For start: 0:42 - wouldn't that make it a roller-locked (instead of roller-delayed) weapon?
1:15 - what makes "locking" piece to move backward? Is it inward movement of the rollers, acting on angled surfaces pointed out at 0:33? If so, what causes rollers to move inward? Is it backward movement of bolt head, something we were told can not happen at 1:06?
Am I missing something here? 🤔
I'm having the same confusion. I've looked at several videos on how roller delayed systems work and so far none of them have explained it it fully.
The Action is absolutely fantastic, as it allows high velocity of the projectile by taking full advantage of the pressure of the gases. You do not need an auxiliary piston that makes you lose energy. The only flaw is the extreme stress on the rollers and the accumulated dirt. That is why the rate of fire and the projectile's exit speed are extremely high. The recoil is light and the accuracy very good. The gun is easy to manufacture, inexpensive and has small dimensions. When I shot an HK-33 I realized that if it weren't for the dirt it would be the perfect weapon.
This action type is reliable despite the dirt.
Concept of Reflected Inertia... The lever ratio explanation is true, and the second half of the explanation really makes the concept of reflected inertia make sense. The lever ratio effectively multiplies the inertia of the heavy mass of the bolt carrier. The internal ballistic equations follow the model of a blowback design, except the mass has been multiplied by the lever ratio. The reflected inertia is then used as the mass in the blowback calculations. There are a lot more to the details to make a roller delayed blowback design work well. The devil is always in the details. The lever ratio uses the principle of reflected inertia as part of a blowback design. The engineers at the arsenal taught us how the HK designs really worked, and the HK trainers always were left holding the bag. That is why the HK manuals and even the HK engineering information are so poor. It was pretty cool to be there when the engineers asked questions. The HK myths were busted.
It is interesting to see those small details being explained. One reason I took interest the the PTR-32 was because caleaning was quick, and that was especially important, given how dirty 7.62x39 ammo can be.
This is a brilliant explanation. Never realised it was sooo simple i thought it was some super complicated shit.
Two things: 1 - When Ian first began speaking I thought he was doing his best imitation of "The LockPickingLawyer" and then 2 - I was just SURE he was going to use the CZ-52 as an example of one of the few pistol designs that use the roller lock design! As always.... great video!!! ;^)
It works by kraut space magic.
Good one!
It does annoy me when terminology is misleading to the neophyte: these firearm "delay" systems actually don't have a true delay, ie, one where no movement starts until after some 'dead time'. They're all based around using mechanical disadvantage to temporarily make a moving part appear inertially 'heavier', temporarily, in order to buy time (the 'delay'). They all also suffer with high case pressures to ammo sensitivity, because there is still that movement required to transmit the energy.
This works because movement splits equally by conservation of momentum (speed times force), but *energy* goes as 1/2*mass*velocity*velocity (or really, half of momentum times speed). (except for gas delay -- those are about reducing the effective area of the bolt face, by presenting another face attached to the bolt facing the other way to 'subtract' it from the effective area causing the blowback.
Anyway, just wanted to point out that confusing terminology annoyance -- no 'delay' system actually has a true 'dead time' delay in it, only 'locking' systems do that. And that's why they all have trouble with increasing chamber pressure, and require fluted chambers or lubricated/extra precise case ammo etc etc for reliable operation.
This is exactly the explanation I was looking for. I simply could not wrap my brain around the written description in my course textbook. Thank you, Sir.
Not only are these videos always great, but this guy is also just SO easy to listen to!
How does it work?
“Very well, thanks!”
I love these videos from you. Not being able to aquire any guns in my country easily your short explanations make it easier to appreciate the operation of the guns you showcase 👍
Hey Ian, I’m really new to firearms and am unable to own one in Arizona where I live because I am a marijuana patient. I can’t have my own fun so I live vicariously through your channel. Thanks for these smaller breakdown videos, I will hear you say things like “well this is an open bolt where this is a roller delayed” and it’s taken me awhile but I’m starting to understand firearms as more than just complicated tubes that make bullet go zoom
He did it! A quick follow-up to roller-locking with roller-delayed!
Thank you for focusing on this. It's just as important to know how something works, as it is, how to make it work.
A roller locked delayed blowback gun that that you proably already know about and have stumbled upon it from time to time, the CZ 52. Very underrated in my opinion and I honestly think that it is actually a really cool looking firearm
Videos like these +++ there is so much to firearms and so few educators out there, you champ
Tilting bolts can also be used for Delayed Blowback as well. But the closest thing we got to it is the Rudd Carbine.
The problem is, the bolt is designed incorrectly. The locking surface should be straight. Not on an angle.
And the carrier should have a few inches of travel, before it actually unlocks.
That's basically how Delayed Blowback works. Inertia is what replaces a conventional Gas Piston.
They aren't good with suppressor? How did they get around that and the MP5 in use by special forces?
Good question
i assume because of the cartridge MP5 use, its only a "pistol" round and can use sub sonic one so it have way less chamber pressure than rifle round like 556 or even 762.
@@prd6617 Makes sense.
@@jantschierschky3461 It's not really the recoil, it's high residual pressure, making the system run way faster than it's supposed to and it running way way dirtier than normal.
@@prd6617 Dunno about using the 3 lug adapter, but on the SD, the effective barrel length ends up being only a couple of inches. After that it's ported into the silencer, so it never gets a chance to build a whole lot of pressure in the first place.
I kept hearing about this with the stribog. Thanks for the info.
Thank you for this channel! can you do a series on different sorts of lockup/delay mechanisms? I've heard of 'radial delayed blowback' and such ar15's now, and as an aspiring gun designer I'd like to compare notes of the survey of actions out there that I've done with the surveys others have done, and it's hard to do that if you're not already established in the gun industry and in contact with many people in it- so having a channel like this is invaluable. Keep up the good work!
Thanks for the vid. Takes me back to my national service times with the G-3.
only the real men can use g3
@@faithismyskyfall Its a good rifle. Accurate, and in a decent caliber. I felt like a wimp being retrained in 5.56 M4 carabines. Not knocking the M4. 7.62 is just a better caliber for me.
Fun story. Some years back, a dumba** behind the gun counter at a local outdoors store tried to sell my dad a G3 clone saying it was gas operated. Thanks to the one gun book 12 year old me owned, I informed him (my dad, not the dumba**) that it used, in fact, something called roller-delayed blowback. The book was very lacking in details, just providing basic info on a wide variety of guns. But even that little bit of good information can make a huge difference in how informed of a purchase you make.
Great video, i like when you explain the engineering of the firearm.
My Sig510's / STGW57's have roller delay blowback. I always had the feeling the point of this is not delay (as it still opens immediately). The roller with the little ramps however compress the main spring for lets say 1 cm, but the bolthead only moves 0.5 cm. So from the bolthead's point of view the main spring is much stiffer the first bit of travel, due to the roller mechanism. This way a lot of recoil is absorbed in the first bit of travel, more than without the roller mechanism.
Thank you. I've always wanted to understand this.
Really liking the mechanical breakdown
Agora a pouco descobri que o HK G33 e o HK G3 funcionam com esse sistema, fiquei impressionado, e comecei a buscar como isso funciona porque é muito diferente do que eu imaginava. Eu achava que aquele tubo acima do cano da arma era um sistema de gás, e que por isso esse era o sistema dessa arma.
Obrigado pela legenda em português 🇧🇷✌️
Também eu, até ter de desmontar e montar a arma na recruta😅. Depois percebi que era apenas onde o manobrador da culatra e a culatra se movem
Love me some roller lock goodness! Keep up the good work!
Ian dropping knowledge on the faithful!
Mauser engineer, 1945: *blank-eyed stare* "Where we're going, we won't need locking lugs..."
i had to come here after the CETME LC video, thanks ian!!!!
I wish you'd expanded on those advantages and disadvantages. I get why it might be dirtier than a typical blowback based on the design, but why doesn't it work well with suppressors? The MP5 and its ilk all use suppressors. And if it works well with cheaper stamped-sheet receivers, why is the MP5 so expensive while the cheaper UMP doesn't use it?
@ 2:25 hasn't the cetme Ameli a roller delayed blowback system?
Yes.
Thanks dude. Simple and to the point.
There's one important piece of information missing: the rollers act as a lever and thus they accelerate the mass faster than the piece behind the cartridge. This reduces the weight of the mass needed by about 4x!
Otherwise, you could just use a normal blowback for a rifle as done with some tripod machine guns...
Very true. You really understand how the system works. Have you ever tuned these actions for use with low power ammo? People that understand what you mentioned get asked to fix MP5 and clones all the time.
@@johnphillips222 LOL. I´ve never handled one in my life! In fact, I´m not legally able to handle firearms.
I bet barrel length and muzzle break will need to be considered as well.
In the case of WWII, it was easy to implement the design, but the ammunition quality would almost guarantee malfunctions. I guess that´s one of the reasons why the MG42 was built slightly differently. For one it used the barrel as additional mass and had a recoil booster. This should make the accuracy and recoil worse, but still, it was a damn good LMG at its time. I bet these changes were because of the ammunition quality. On the other hand, the allies failed to copy the design for their own ammunition indicating that the adjustments are very subtle but essential...
Jeah in German the locking system of our G3 is called " Übersetzter Massenverschluß " The direct translation would be " weight operated locking system with transfer ratio "
@@heikopanzlaff3789 Yes. I'd translate it with leveraged inertia, but I'm not certain about _Verschluss_ as that word seems to be a bit broader in meaning than locking. A cork in a bottle could also be a _Verschluss_ and the operating system is not truly locked...
you cant do normal blowback in a rifle. if you did the math would work out to somehting like a 30lb bolt. lever is a necessity
excellent clean and informative video
Still don’t get it...can we have another video lol
It's about the inertia of the bolt carrier. The idea is to let the powder charge finish burning (and the bullet to get all the way out the barrel) before the bolt starts moving back.
But sure, another video wouldn't hurt. ;>)
Try the video of the Korth automatic pistol if you're still unsure.
I’m building a Cetme and was wondering how my bolt head fit inside my frame. Now I know. Thank you
Mad respect for stripping down that bcg, I actually hate putting that back together
After almost a half hour spent on watching this video, and a couple other videos on it, AND reading up on it, I finally had that eureka moment on how to properly mentally visualize and understand how a roller delayed blowback system actually works. My gosh, that took me way too long! Hahahahaha!
I had to put it into much simpler words for myself in order to actually understand it. Maybe I just need to sleep lol.
Nah the guy doesnt explain it properly what moved the bolt carrier back if the breech is held in place
I love these technical videos! 👍
while im serving in military i used hk33 as a primary gun it was little bro of g3 but i still couldnt get the how does it works. after this video i still dont get it
It seems that in all of the animations, the bolt carrier moves before the bolt lock. How does this happen? What force causes it to move?
Heard u talk about this so much and always wanted to know what u meant and now I do👌🏼
thanks Ian! always wanted to know how h&k's work!
Nice! So good to have easily understood videos showing the difference between roller locked and roller delayed blowback guns. Mixing the terminology has sadly become the norm.
An argument can be made that roller delayed could also be roller locked. (like how all bourbons are whiskeys, but not all whiskeys are bourbons) During firing in a roller delayed blow back, the rollers do technically mechanically lock the bolt to the trunnion/barrel...
@@2k7duramax That's the point. It never IS locked.
So the cartridge case is the gas piston. It is, think about it. Successful roller delayed machine gun, S.I.G. 710. A very good machine gun.
Wouldn't the HK 21/23 be considered a viable roller delayed blow back machinegun?
Yes and no. So yes, it is, but it's really the same as the HK91 action but with more infrastructure around it. Dedicated machine gun implementations of the system (MG42V/MG45, SIG 710) didn't take off.
@@ForgottenWeapons Fair enough. I understand that it was an off-shoot adaptation of the G3, and not designed as a blank page ground up general purpose machinegun. I just thought that since it was intended to and did fill the roll as a GPMG, it counts.
@@ForgottenWeapons did you forget about the CETME Ameli? Roller delayed blowback 5.56 mg.
The Korth .45 ACP is designed with a roller blowback delay breach. The bottom half of the pistol looks like the 1911, the slide is another animal.
And SRM Arms managed to make it work in a shotgun. Even H&K complimented them saying they figured out something they've been trying to get to work for decades and couldn't.
If there isn’t any gas system, how does the locking surface move back? Since the rollers are locked in place already, where is the force which moves the bolt carrier back coming from?
--as I clean my P9S in .45 ACP. Thank you Ian.
for some unclear reasons, roller-delayed blowback is my favorite firearm mechanism. Probably because of watching HK slap in the first shooter game I've ever played
man roller delayed machines are amazing. only the real man can wield them.
The slap makes a very pleasant sound
What did I learn? That firearms designers are some really clever people, even if accidentally!
Love this series of explanatory videos. Could you do one about the difference between hammer fired and striker fired please?
homemade gun builders are taking notes right now
Thank you, Ian .
What I've learned about Roller Delayed Blowback is that it feels like just a Flapper Lock with extra steps
Based on your description, it sounds like the difference between roller delay and roller locking is one of degree. Both are gas actuated. Roller locking sounds like it travels further up onto the flat and in doing creates a longer period of delay, or locking for the entire firing impulse?? While roller delay, since it is parked on the angle is starting to retract immediately and so isn't fully locked. Am I tracking correctly? I am thinking that perhaps I am missed something?
They're not gas actuated, unless you count the gas that's inside the cartridge case. A roller delayed system is never fully locked, the rollers and the angled locking piece merely act as increased leverage so it takes more force to accellerate the bolt rearwards than its mass alone would suggest.
In a roller locked system, the bolt is fully locked and needs to be unlocked by some other force than blowback from the pressure inside the cartridge case. Most commonly this is done with a short recoil system, where the barrel and bolt move rearwards together for a bit until the rollers are disengaged by a cam or somesuch. There's no reason why you couldn't build a gas operated roller locked mechanism, though I cannot think of any.
In a short recoil system, the slide+barrel start moving immediately (although locked together), and it's the combined mass+recoil spring that defines when they hit the cam and unlock. Which defines the pressure at unlocking.
In a roller delayed system, the slide (or bolt carrier) start moving immediately (while the bolt is still locked with the barrel), and it's the mass of the bolt carrier+recoil spring that defines when the rollers retract and the bolt unlocks. Which defines the pressure at unlocking.
In short, I fail to see principal difference between short recoil and roller-delayed blow-back.
Of course, rifles rarely use short recoil, which seems to suggest that both systems are insufficient for rifle cartridges.
But why is it not used more in pistols? Seems like a win - the barrel can be fixed, which increases precision and decreases manufacturing costs (if you've ever fitted a proper "oversized" barrel you know why).
maybe because, while in a rifle you naturally have a bolt carrier and a separate bolt, in pistols you'd have to introduce an additional part? But then Beretta have their moving locking block, for example.
Roller delay doesn't actually lock the bolt to the barrel.
love my hk 91 like no other
While rather simple from the operator's point of view, as compared to the gas-operated system, this design is quite difficult and expensive to produce, and requires a very precise manufacturing. Also very tough = expensive materials must be used for the rollers and other locking parts, because they are under very high stresses. That, IMO, is why it was never used by almost anyone else other than HK (at least, AFAIK). I always wondered why they just didn't use lever-delayed blowback, like the Kiraly system, achieving the 4-to-1 transmission ratio would be quite trivial with a simple lever (of course, probably there were some reasons for that; probably, the use of a stamped receiver is the reason - the rollers allowed to use a small barrel extension for locking, and the rest of the weapon could be made from sheet steel; lever-delayed blowback seems to require a more substantial receiver - AFAIR even the FAMAS uses at least partially milled receiver).
What's a fluted chamber and how does it work?
It's where they machine some small slots down the side of the case neck to borrow some gas to push against the case and improve primary extraction. Once the case is moving, it's fine. My Tokarev SVT40 has a fluted chamber, as do pretty much every HK firearm.
Great videos. Many thanks!
IT JUST WORKS
Nice LC, i'll like to see it's front post; if it's solid... it's not the one that we had on all the CETME L/LC/LV ARs.
It would be cool to see links to roller delayed systems you have analyzed.
So I'm guessing if there isn't a gap between the bolt and a carrier like the specs ask for the rifle will rail to cycle since theres no room for movement of the bolt head post firing?
Thanks Ian
it's like a roller clutch 😮
thank you, really big help.
So if one took a roller delayed rifle and welded it to an immovable stand, it would not cycle? Put another way, it needs the recoil of the rifle to move the bolt within the rifle and make it unlock?
it looks like the rollers would push the bolt rearward, not hold it in place. Wouldnt there need to be something ahead of the ramps on the bolt for the roller to lock on to it in order for the bolt to be held in place?
Do have any gun design ideas Ian? Love to hear some interesting thoughts.
He's answered this question various times, and the answer is always "No." He's a historian, not an engineer. He's also waxed poetic about the futility of trying to become a firearms designer in these modern times of highly developed and successful firearms. I agree with him. It's not impossible, but the days of "Hey! I've got a great new idea!" are essentially over. Today the route to firearms design lies in learning to be a quality machinist, getting a job with a manufacturer, and then convincing that manufacturer that you have an idea worth exploring. The last one is actually the hardest.
@@tarmaque I make puzzle locks and could try make something mechanical but what?
@@Commissioner. I think you should get into fluidics, and build a hydraulic computer.
@@tarmaque I'm taking a class on basic chips, I was wanting to layer/wafer signals to create a schizophrenic effect. Maybe a step toward AI
@@Commissioner. Maybe you should include piezoelectric components to complement your schizophrenic effects. (I just like how those words sound together.)
want to ask, what was the rifle with hollow chamber in the bolt carrier, half filled of something like sand or metal powder? trying to google it but not successfully at all.. seen pictures of that year ago or so.. any ideas what rifle it was?
Ian is the BEST! :)
Thanks Ian!!!
Love my C308
Isn't loose tungsten shot inside the bolt carrier an essential element for reliable roller delay operation?
Thanks for sharing videos.
Ok, so it's basically a more compact version of lever-delayed blowback. Very clever.
Yeah, I get it, but I like mechanisms like this tho.
Ian, not sure if you read these comments.. but i need gun jesus on an issue with a roller lock i just bought. Bought a c93, when it came in the charging handle was seized, knocked it loose but it's been sticky and harder than normal to pull back (my ptr91 is vastly easier). I took it to the range, it'll load just fine, but when it fires it won't eject the spent brass. It'll stay on the bolt head and try to rechamber another round with it there. I've tried fb groups and no one knows anything about this. Any help would be greatly appreciated!
Makes me want a cetme.
i don't understand how the bolt goes backwards since there's no gas tube is it the gas that moves the entire bolt group back inside the chamber that causes the whole thing to go back before it's pushed forward in place by the spring ?
Thanks! That's what I wanted to know.
The HK21 and 23 GPMGs are roller delayed and were/are used by several military and police forces all over the world.
@forgotten weapons what do you think about the savage a17 that uses a delayed blowback to control the hmr17 in a semi-auto?
Good video. I wondered about that.
Did this channel do a video on the mccrudden light machine rifle of Australian origin? I saw a pic of the gun the other day and thought it must have a cool story behind it, or at least an interesting mechanism.
I legit had my Wi-Fi turned off and this notification popped up. Gun Jesus miracles are real!