Delayed Blowback System in Firearms

[@TheMouseGunner]

If you are wondering what program I use for the creation of this video, please check the description. It should be included on every video in this series, if not let me know.

[@Hassan_MM.]

Sir, If the Bullet goes forward by Pressure,what thing pulls Case and Bolt Backward till the case is ejected?

[@golferchin76]

@@Hassan_MM. this is how the mechanism of roller delayed blowback design works. commons.wikimedia.org/wiki/File:Delayed_blow_back_breech_with_locking_rollers.jpg commons.wikimedia.org/wiki/File:Delayed_blow_back_breech_with_locking_rollers_(en).svg The delay is measured in the microseconds.

[@markaplier1261]

Something is not explained exactly right in this video I noticed. You mention that the two rollers cant move back and so instead move inwards. This is not true. The rollers do move backwards, but just at a different paste as the bolt body. Those two angled surface where the rollers push uppon are like that to make the bolt body move backwards at a greater speed than at which the boldhead is moving at. This does two things: 1. A small movement off the bolthead requiers a greater lenght of spring to compress than if there wasnt this mechanism, momentarily resulting in a bigger force resisting the opening of the chamber. 2. The moment the bolthead has unlocked, the recoil has mostly faded, therefore there being no firce left pressing on the bolthead to cylce the action. The force which was pushing on the bolt head has, via the rollers and cammed surfaces, axelerated the boltbody, which by its onw enertia then cycles the action, hereby reducing the ejection pressure.

[@BUZZKILLJRJR]

Good job very very detailed I'm glad I watched and learned.

[@ieruza]

Thank you for helping us understand and unlock some of the secrets behind this kraut space magic.

[@p-mac5969]

I thought it was originally Spanish

[@tacticalsapper]

@@p-mac5969 Still German engineers (from Mauser / HK).

[@nopnopnopnopnopnopnop]

We were using AG3's in the army and they didn't even teach us how they work. Now I actually understand what the rollers are for. Thanks! PS I would definitely subscribe for more firearms theory/design videos

[@Ratkill]

WoG is probably the most underrated programs out there. What a blessing for the DIYer and developer.

[@Darth-Nihilus1]

I always wanted to fully understand my Hk 91 and this video really helped. Thank you. There was a bit more to it than I was thought

[@rogerbussiii]

I came here with no knowledge and left with a complete understanding of the systems described. Thanks for taking the time to explain what u clearly have a great understanding of.

[@abstractapproach634]

Be very careful with the words "complete understanding" one could spend their life looking into the fluid dynamics and effects of weight in which places ect.

[@graysona1800]

I experienced the eureka effect for how the roller delayed system works at 6:27 and it was probably the best feeling I've had to experience thus far in my life. I just have to put this out there sorry ;)

[@Failcastgame]

same!

[@neutronalchemist3241]

Unfortunately the clip is wrong. In a roller-delayed, lever-delayed, radial-delayed blowback (the principle is the same) the bolt body doesn't "move before the bolt head can move" like it's stated here. Otherwise there will be nothing pushing it. The bolt body and bolt head MOVES AT THE SAME TIME, but, due to a device (rollers, lever, inclined surfaces) the bolt body has to move FASTER than the bolt head. To accelerate something to a faster pace in the same time requires more energy, so the system absorbs more energy than it will if a bolt of the same total weight would have been used in a pure blowback gun, and that's the working principle of roller-lever-radial delayed blowbacks. THEY SIMPLY TRADE MASS FOR SPEED of a part of the bolt.

[@Laotzu.Goldbug]

Neutron Alchemist yes, this was the biggest difficulty for me to overcome. I've been wondering for years, even after I got my hands on an actual MP5 bolt carrier group, how exactly the little wedge, the "locking piece" could start to move before the bolt did. I thought there was some kind of little cut out or piece that protruded directly into the chamber that the rear of the cartridge case pushed on, because otherwise I don't see anything that could cause it to move rearward. It was only until I realize that both pieces of the boat were moving backwards, it's just that the head could only move a microscopic amount to cause the rollers push inward, just pushing the little wedge back. I don't know how to describe it, but it was a very strange feeling to finally _grok_ it. Telling people that the bolt head doesn't move _at all_ until the rollers unlock is very misleading.

[@bobbowie5334]

@@neutronalchemist3241 Not really. The *roller delay* system has no _bolt accelerator-_ so _roller_ delay and _lever_ delay work on different principals.

[@neutronalchemist3241]

@@bobbowie5334 In a roller-delayed system, the rollers accelerate the bolt body in respect to the bolt face. The principle is the same of lever delayed, it only uses rollers instead of levers. upload.wikimedia.org/wikipedia/commons/0/0a/Roller_delayed_blowback_action.svg the single roller Korriphila works the same way. It accelerates the slide in respect to the bolt face. modernfirearms.net/userfiles/images/handguns/germany/hg176/1287735916.jpg

[@scottdyson3597]

Thank you, this has to be the best visual and technical explanation for the mechanics of these systems

[@msh441]

I learned something! Thank you! Facinating to umagine the development of these designs (and other complex machines) befor the days of CAD. Brilliant minds.

[@scratchyass2369]

i tell way this beats the ever loving shit outta those vids where they just play the animation and slow it down and zoom in barely at all. thanks man!

[@Akira-nw4jl]

Excellent video, I also totally agree with the comments made by Vincent Yossarian were most people do not know how firearms work and worse off they don't seem to care. Thanks

[@spencerderosier6649]

Thank you for the in-depth look. There were some very specific things I wanted to understand

[@JohnSmith-id4ut]

Just wanted to thank you for these videos. I've built 50+ firearms and am very familiar with most of the topics you've covered but still find myself learning new things. Also seeing the x-ray helps to better understand the functionality. Great job!

[@ThrowingItAway]

holy crap. it took this animation and your explaination at 6:39 to understand how it delayed the blow back. Thank you so much as it perplexed me for a while.

[@neutronalchemist3241]

Unfortunately the clip is wrong. In a roller-delayed, lever-delayed, radial-delayed blowback (the principle is the same) the bolt body doesn't "move before the bolt head can move" like it's stated here. Otherwise there will be nothing pushing it. The bolt body and bolt head MOVES AT THE SAME TIME, but, due to a device (rollers, lever, inclined surfaces) the bolt body has to move FASTER than the bolt head. To accelerate something to a faster pace in the same time requires more energy, so the system absorbs more energy than it will if a bolt of the same total weight would have been used in a pure blowback gun, and that's the working principle of roller-lever-radial delayed blowbacks. THEY SIMPLY TRADE MASS FOR SPEED of a part of the bolt.

[@conormarie4310]

So is the general principle of this type of system to add inertia to the initial stage of the blowback cycle that is then overcome to allow a lower inertia bolt to finish the cycle? So that would mean the action isn't held closed or locked at the start of the cycle it's just got more resistance as if it were a really heavy straight blowback bolt?

[@julian21441]

I love the HK roller system, I don't know how I stumbled across your video now but it would have come in handy before I first field stripped my Ptr91 GI. I had stripped it all down to the bolt and trigger assemblies and put it back from memory lol luckily its a pretty simple enough system to understand

[@DiRtYwHiTeBoii]

I'm a visual learner and needed this video lmao. I was watching another guy's video on roller delayed systems and was like 🤔😧🤯 thanks for the knowledge 🤙

[@vukos]

Great explanation of the roller delayed blowback system. I am now educated

[@KarlShota]

Much thanks for the in-detail explanation on how delayed blowback works. I was wondering how roller delayed blowback worked on the G3 family (of which our lovely MP5 is derived from, along with the PSG-1 and HK21 and their variants) worked. I'm likely to re-watch it a good number of times to drill into my head how it works.

[@JerresYouTubular]

Shhhh!! Working on a new type of Fixed Barrel/Compound Recoil design for (Target) Pistols. Its not like any other semi-auto feed and extraction system I've seen. I Got the idea in 1991 and still to this day no one has developed anything close (I have researched 130 years of semi-auto designs and patents to make sure). I'm retired now, so i have time to start working on the blueprints and building a working prototype.

[@jeff-ph9bc]

This is the coolest explanation + graphical presentation!

[@vincentyossarian7736]

MouseGunner, THANK YOU for the very, very excellent and detailed explanation of the various operating systems! I really can't believe there's only 2 other comments on this, and so few views, I guess not that many people really care how things work, as long as they work. I am always horrified by how many of my friends who have been driving for decades have no clue how internal combustion works, or disc brakes, or the simplest appliance... I find it troubling, and frankly, a little depressing. Anyway, I have just watched this first video of yours, but as soon as I'm done writing this comment (and sending the link to all of my firearms-enthusiast friends!), I''m going to watch ALL of your other videos. I am actually a student of design/engineering, and have been designing military-style rifles and pistols as a hobby for some years, while concurrently learning AutoCAD to model the designs... Not saying I will ever be building any of them, but it is a very fun and rewarding pursuit, and you never know; I might come up with a design on my own, or through collaboration, that merits some prototyping! In the meantime, your video(s) are thoroughly enjoyable and fantastically helpful resources. Please, keep up the good work!

[@TheMouseGunner]

Thanks, I am glad you liked the video.

[@kita7647]

So many people watching now :)

[@chuckabbate1264]

These videos are the best I have ever seen. THANK YOU! Have you ever done one on a full auto trigger system?

[@TheMouseGunner]

Yes. kzbin.info/www/bejne/hpKpeaind9J3o80

[@killiotta1]

i hate how you have to grind on this game (World of Guns: Gun Disassembly) just to get most of the guns you really do want. such a pain.

[@giovannirana1715]

Just buy them, its like buying a normal game you pay 80€, you cant expect much more since its free

[@chrisv3329]

i just waited for the all guns access to go on sale for 20 bucks then bought it

[@merkymurk7534]

@@giovannirana1715 yeah, they're putting all this out for free, fully detailed gun models for $0. paying is not a premium its more than enough for the effort they are putting in to make these guns.

[@NMranchhand]

Outstanding explanation

[@jaysjourney8436]

@ 5:22 you refer to the cutouts for the rollers as being part of the "receiver" that is actually still inside of the "Bolt Carrier Group." other than that i thank you for going over it in a youtube video so i didnt have to download something or figure out blown parts schematics =)

[@georgegordonmeade5663]

Okay, so what starts the movement back of the bolt on the MP5? We got two parts, the bolt face, and the bolt (with wedge), and the bolt-wedge starts moving back before the bolt face? What's pushing the bolt-and-wedge back before the bolt face? Cuz the blowback is coming from the cartridge case, which should be pushing against the bolt face, right?

[@tharrrrrrr]

Correct! And that energy is first transfered through the bolt head to the bolt body (the locking piece) according to the same principle that makes a Newton's Cradle work.

[@simeonges1]

That "...little bit of time that it takes for those rollers...", of the H&Ks is 1/16". Nice video!

[@Bill97070]

That was a fascinating presentation of a blow back system or any system using technology to view the inside workings. I'll look into the links you provide. Thanks so much.

[@ortbrant77]

I've read some comments but I still don't understand how the first part can start moving if the case is completely still. Is the case deforming and creates a bulge that pushes the firing pin?

[@000Mazno000]

Just because it isn't moving, doesn't mean it isn't applying force. Consider that, because of pressure in the barrel, the case is pushing back HARD on the bolt until it fully exits the chamber.

[@tharrrrrrr]

I was wondering this too, and I found a good article which explains it at www.americanrifleman.org/content/roller-delayed-revival-the-heckler-koch-sp5k/: "To delay the opening of the action, the force of the fired cartridge’s expanding gas is transferred from the bolt head to another heavier component in the system-in the G3, the barrel extension, bolt carrier and action spring. Think of the Newton’s Cradle physics toy. If you pull two of the suspended spheres away from the other three and release them, they impact the center sphere, which stays stationary, but transfers the force to the two opposite outer spheres, causing them to swing away. In roller-delayed terms the two outside spheres on one side are the force of the cartridge firing, the center sphere is the bolt head and the two spheres on the opposite side are the barrel extension, bolt carrier and action spring."

[@michaelw.urbansr.8617]

I did stop the vieo in the 1st 2mins because i realize this is an older vieeo and i dont know if the Radial Delayed Blowback system was even created as of then by CMMG? I recently purchased a Barrel/BG combo of the CMMG radial delayed blowback system and paired it with a dedicated Range609 lower receiver and Angstadt Arms dedicated AR-9mm/45ACP/40cal upper. The one without a forward assist and larger ejection port. Im not sure if i will like it though only because i cant put on a port cover and its got an open gas port for a gas system....so far i havnt found any plugs for upper with gas ports for the CMMG radial delayed blowback system since theres no longer the need for a gas system. I dont want the gunsmith to have to weld or plug the port with lead? I want to be able to use the upper later if ever needed for another rifle that may not have a delayed blowback system? So i may have to purchase one of CMMG's upper that are made for their radial delayed system? Only because im thinking they would make them without a hold there?lol idk not an armorer or gunsmith and pretty green even after 9yrs in the hobby late in life! I got addicted immediately! My 1st was the typical 38Spcl for home protection and the 1st time i shot it i went out and purchased several other handguns and long guns within a few months! That 38 will always have a place in my heart and will never sell it and it will always remain in my night stand next to the bed. Nobody but my wife and i now so no bull about locking it up! lol finally got her to go to the range with me once after 7yrs in the hobby and she loved it but has a condition that is aggravated by the pressures produced even by a .22LR round going off indoors. Living in the bluest state in the country means we have one handgun range any where near us so she cant shoot with me anymore. Not 30mins into her 1st time shooting and she started talking about buying her self her own .33LR pistol or revolver? LOL But thanks to our blue state there are restrictions for everything. We cant take handguns or 22LR long guns to any public ranges as they must be more dangerous. And only recently were we Subjects of the empire were given permission to shoot our sporting rifles at said public ranges. In any case im building this new .45ACP carbine with high end parts and making it a one of a kind to make it even more special for me! I love the AR configuration and family of firearms as anyone can get into building them while watching a youtube video or 10!!!LOL Thanks so much for your video it was cool!

[@spapi3880]

Great video Rick Moranis.

[@lorrewatkins5925]

I just stumbled upon your video. Great work man ! U did it in a very intuitive way. Keep up the good vids !

[@a155fgd8r]

Hello, what program do you use to do this? Thanks very much

Excellent explanation with technical details regarding engineering. Laymen, enjoy this video because with it you will begin to understand the physics of weapons. ANGRY!

[@michaelw.urbansr.8617]

I also realise your not using an AR15 as an example and my CMMg radial delayed blowback system is such. So I think the last part i need for the build is some kind of plug for the open gas port in the upper?Just not sure if there is such an animal or if i have ot buy yet a 3rd upper in my quest for the perfect one? hehe HELP???

[@adrianhartanto1257]

I'm still wondering about how the bolt carrier moves inward first while the bolt head haven't been pushed yet. is there like another gas tube that leads them to push the carrier? or is it just a mistake on the animation part?

[@tharrrrrrr]

Part of the energy from the black powder explosion travels through the stationary bullet casing, through the bolt head, through the bolt body, to the bolt carrier, and applies enough force to push back on the recoil spring. When that happens, the bolt carrier moves backward, taking the bolt body back with it (because they're attached), which then allows the rollers to contract inward, which then allows the bolt head to travel backwards.

[@robertkf1]

Great series on firearm operations.

[@justinm2037]

so am i understanding that the action is similar to a neuton's cradle somehow the case rearward impulse passes through the bolt head then the back half starts moving back and grabs the front half unlocking and extracting?

[@tharrrrrrr]

Yep!

[@chillchillpill]

Question - is the blowback system a bad idea for a rifle like the FAMAS?

[@lepmuhangpa]

@warface gamer56 Damn, I don't need to add anything.

[@billcasso5428]

Thanks this is an excellent explanation

[@mikebennet7697]

The rollers should be moving in simultaneously as the locking piece starts to move rearward, not after it starts moving. Their inward movement is what drives it rearward. Also the bolt head does start to move very slightly to the rear as the rollers compress inwards, its just too slow to expose the thin cartridge case walls before the bullet exits the barrel and pressures drop to safe levels.

[@tharrrrrrr]

From what I've read, their inward movement is not what drives it rearward. It's driven rearward by the transfer of energy to the bolt carrier (to which it is attached) and recoil spring. The energy transfer occurs in the same way as it occurs in a Newton's Cradle children's toy.

[@jackbomb88]

what website or software did you use to see all different internal parts of the weapon?

[@kylewalton7005]

at the beginning you mentioned the case making a case seal. then why do all these delayed roller bolts have fluted chambers?

[@smolboyi]

So the px4 storm is like a rotating barrel delayed blowback?

[@p0331546]

8:19 lol have you tried cocking a G3? you gotta muscle the first few cm of the cocking handle to get it going

[@bhartveersingh1865]

Good job man love u from India Punjab Amritsar

[@DarthJabba504]

4:35 What is causing the rollers to move back if the cartridge is locked in place at the time of firing?

[@zeromech1450]

The force of the gasses push back the bolt. And I assume return springs push those rollers in. Personally I feel like this is really over designed.

[@250smacks]

The price difference between having delayed blowback or straight blowback is ridiculous. How many fgc9s can you build for the price of 1 mp5?

[@ERICMARIONLLEDO]

Wow! Amazing video! Fantastic job!

[@liggerstuxin1]

2:36 he’s trying to show the delay but the computer is showing the piston moving through same speed basically.

[@coolicetea7923]

Thanks for the inspiration.

[@BoBaH_BoBaHoB]

Are there barrel-blowback SMGs ?

[@wolfsProjectFiles]

Very informative video. Thanks for posting.

[@smolboyi]

What a well done video, wow, thank you

[@BusinessWolf1]

Awesome video!!

[@RADIOACTIVEBUNY]

The rollers don't necessarily start moving inward immediately as the wedge retracts. They have no force pushing them inward applied to them until the bolt head begins coming back as well, dragging them against the trunion, which then pushes them in.

[@TheMouseGunner]

I did say the rollers ride along the sloped surface, implying rearward motion as that is how they would do so, but you are right that I did not perhaps make that as clear as I should have. Most of my older videos were done unscripted and all in one take originally, this being one of the first videos of its type that I made, so they are a little rough around the edges.

[@Holescreek]

Just a point of clarification. The rollers are captive between the trunnion ramps, the front faces of the bolt head, and the locking piece shoulder angles. The pressure of the discharged cartridge against the bolt face is what forces the rollers against the trunnion ramps squeezing them inward against the locking piece shoulder angles. The roller pressure against the locking piece shoulders pushes the carrier rearward against recoil spring pressure. The video is graphically superb but the description makes it appear that the carrier moves rearward (before the rollers start to retract) and then the bolt head follows. Great job on the graphics!

[@AdurianJ]

The G3 looks just like this on the inside as well.

[@WolfRichter337]

that is because the mp5 is a derivative of the g3

[@jason200912]

it's just like a direct blowback that they use for the scorpion evo

[@crazywelder72]

This is the first time I've seen your channel. Definitely excellent explanation and animation. What software did you use? This definitely doesn't look like solidworks and I love this

[@zemial74]

What program you used for this animation

[@apb2887]

The Germans used rollers in ww2 on the MG42 to speed up the cyclic rate. I'm not 100% certain but I think that was the first gun the design was used in?

[@darnit1944]

adam briar Rollers were used in the 42, yes. However it doesnt use blowback. The first roller delayed blowback was to the successor of the StG 44 which is StG 45.

[@jarrar1]

Real good man. Thank you.

[@falco13007]

great video, thanks!

[@touge242]

7:15 Finally got it. the system is kinda like a side release buckle

[@Bonavire]

I literally was just using this game, got curious what delayed blowback actually means, and the video I find is using the same game to explain it 😂

[@golferchin76]

One can easily understand the mechanism of roller delayed blowback design with the following. commons.wikimedia.org/wiki/File:Delayed_blow_back_breech_with_locking_rollers.jpg commons.wikimedia.org/wiki/File:Delayed_blow_back_breech_with_locking_rollers_(en).svg The World of Guns game software is a game software not designed for what you were trying to do. Also keep in mind that as soon as the bullet starts to move forward in the barrel, the whole bolt assembly starts to move rearward. The delay is measured in the microseconds. (meaning bolt assembly is already moving rearward, while the bullet is still in the barrel)

[@BAdventures]

I've used a real MP5. Low recoil ad smooth shooter. Good 3D model and explanation 👍

[@fornello123]

what causes the 'wedge' to move?

[@tharrrrrrr]

I was wondering this too, and I found a good article which explains it at www.americanrifleman.org/content/roller-delayed-revival-the-heckler-koch-sp5k/: "To delay the opening of the action, the force of the fired cartridge’s expanding gas is transferred from the bolt head to another heavier component in the system-in the G3, the barrel extension, bolt carrier and action spring. Think of the Newton’s Cradle physics toy. If you pull two of the suspended spheres away from the other three and release them, they impact the center sphere, which stays stationary, but transfers the force to the two opposite outer spheres, causing them to swing away. In roller-delayed terms the two outside spheres on one side are the force of the cartridge firing, the center sphere is the bolt head and the two spheres on the opposite side are the barrel extension, bolt carrier and action spring."

[@darnit1944]

Anyone care to explain why the G3 is very prone to getting carbon built up? Is it because the blowback gas often flows to the action and thus leaving residue or something?

[@garretthart13]

is this an available program or you custom modeled all these yourself ?

[@TheMouseGunner]

Information on what I use is in the description along with links.

[@Kdot_99]

What causes the markings on the casing after its been ejected from a roller blow back system?

[@TheMouseGunner]

I apologize for missing your comment. Are you referring to a G3/CETME rifle? If so the marks I believe you are talking about come from the fluted chamber. Fluting in a chamber helps with extraction, as the pressures involved with .308 being fired in a roller delayed rifle can be on the high side.

[@c-ro311]

So, the first part is kinda like a gas operated, but with rollers, right?

[@Lilcyclop]

Praise the Moon there are many different types of gas systems.

[@neutronalchemist3241]

Really not. In a gas operated firearms, the breeck is locked until the gas (via a short stroke piston, long stroke piston, or direct impingment) unlocks it. In a delayed blowback system the breech is never locked. In a roller-delayed, lever-delayed, radial-delayed blowback (the principle is the same) the bolt body doesn't "move before the bolt head can move" like it's stated here. Otherwise there will be nothing pushing it. The bolt body and bolt head MOVES AT THE SAME TIME, but, due to a device (rollers, lever, inclined surfaces) the bolt body has to move FASTER than the bolt head. To accelerate something to a faster pace in the same time requires more energy, so the system absorbs more energy than it will if a bolt of the same total weight would have been used in a pure blowback gun, and that's the working principle of roller-lever-radial delayed blowbacks. THEY SIMPLY TRADE MASS FOR SPEED of a part of the bolt.

[@BlackMaskq]

Thank You

[@millercmdn6805]

So glad I found this video 😂

[@chill2237]

can you do rotating bolt operation, like a m14 or grand action??

[@babotond]

I just wanted to ask the same!

[@Foxhound_J]

Great video

[@1906Farnsworth]

I don't see the merit of this design. A locked breech system would actually be simpler, wouldn't it? Can anyone explain this?

[@实诚-i9p]

what is the software？

[@michaelcollins106]

You have no idea how this system works and it shows.

[@jukeboxhero1649]

Well, dude, you need to show what's squeezing and such

[@brianpencall4882]

The rollers are not "sucked" in. The rollers are pushed in. The Swiss did this best.

[@findog187]

Hk rifles use fluted chambers that aid in case extraction. Your model does not illustrate this.

[@TheMouseGunner]

Not my model, I use a program listed in the description of the video. I am aware that the program has issues, as I point out the poor timing of the moving parts in this video. On the other hand, the purpose of this video is to impart a basic understanding of how delayed blowback systems work, and for that purpose the program is adequate.

[@excidium2568]

think about it, this program is a free to play "game" on steam.

[@AgoristAlex]

Thank U!

[@myusername3689]

This is why I dislike delayed blowback. They have a problem with brass cases.

[@milmech4376]

sounds like the dude that does those funny videos where he makes suasages out of weird things and tries it

[@kemperwoodruff758]

Awesome!!!!!

[@thinzki44]

It's called magic secret revealed.

[@BushmasterXM15E2S]

Why aren't blowback systems the preferred systems instead of gas systems?

[@TheMouseGunner]

Although delayed blowback systems can chamber rifle rounds, modern gas operated systems handle high pressure much more easily. For instance H&K had to use a fluted chamber to help with extraction in the G3 rifle, because of high pressures during extraction.

[@neutronalchemist3241]

In any blowback system, the case starts to move backward when the pressure is still at unsafe levels. Otherwise there will be no movement at all. That's not a problem for pistol cartridges, that are short (so with a limited contact surface with the chamber), and operate at relatively low pressures. It's a problem for long rifle cartridges, that operate at higher pressure, and have a wider surface that is stuck by this pressure to the walls of the chamber. In those conditions, small differences in the condition of this surface (brass or steel, presence of water, of oil...) can have great effects in the force with which the case pushes the bolt rearward, and so in its speed, and so in the safety of the system.

[@neutronalchemist3241]

In a roller-delayed, lever-delayed, radial-delayed blowback (the principle is the same) the bolt body doesn't "move before the bolt head can move" like it's stated here. Otherwise there will be nothing pushing it. The bolt body and bolt head MOVES AT THE SAME TIME, but, due to a device (rollers, lever, inclined surfaces) the bolt body has to move FASTER than the bolt head. To accelerate something to a faster pace in the same time requires more energy, so the system absorbs more energy than it will if a bolt of the same total weight would have been used in a pure blowback gun, and that's the working principle of roller-lever-radial delayed blowbacks. THEY SIMPLY TRADE MASS FOR SPEED of a part of the bolt.

[@a.t6066]

Why does the mp5 have delay rollers?

[@impactaustria]

With this kind of delaying mechanisms you are able to cut down on bolt mass to have less moving mass inside the firearm. That keeps the firearm steadiear during cycling and is easier on parts. Mass is the essence of each blowback system since it provides resistence in the form of inertia to keep the bolt closed long enough for the chamber pressure to drop to save levels. Without clever delaying mechanisms a lot more bolt mass would be required which increases even more once you step up to more powerful +P ammunition or even rifle rounds.

[@johnrussell3755]

u made my day

[@wallyborrero4967]

I'm sorry I'm kinda new to all this stuff but is this the same as Gas Operated System.

[@makkaschatsanddits7899]

Yea Im not sure if hes just talking to gunsmiths or hes trying to educate us.

[@TheMouseGunner]

No, that is why I have a separate gas operated system video.

[@keskinpastane7761]

almost same thing but in gas system gas piston unlocks the lugs then let the recoil set the rifle but in delayed system recoil does everything no gas piston bolt locks it self and recoil unlocks it after bullet exits barrel

[@keskinpastane7761]

i have question for u i will make a carbine but i dont want to use gas system and i am too stupid to make it in delayed system it says 1kg for bolt weigth if i make it in blowback what if i make 300 gram bolt and 1kg spring ?

[@brandonrasmussen6692]

.....this guy has never shot an hk91 /ptr91 a day in his life , their lock up is super stiff to unlock and the recoil spring is way more stiff than say an Ak47 by about x2.... I own both PTR 91 and Norinco type 56 ak

[@blakepratt5573]

These rollers press in *HAAAARRRRD!!!*

[@nguyenminhle8694]

6:04, 6:22 i should see a therapist ==))

[@knightxxix]

I dont have to buy to play an animation in the app . all gun in the KZbin.

[@nobodykn0ws520]

Good video...condense it though.

[@jeetenzhurlollz8387]

when he said HARRRRRRRD at 1:07, i got scared

[@ahsanaqib1014]

Can you do a video on AN-95?