CMMG Banshee: The Unique Radial Delayed Blowback System

[@sherman128]

I know this channel is called "Forgotten" weapons but I really like seeing any gun so long as it's interesting in form, function or history. EDIT: I will say that my favorite videos are bad guns. Guns that have massive problems or have a crazy history attached to them. Certainly the most interesting videos for me. (I'm Scottish so the whole exercise is academic for me, so I get more from a crazy story than a description of how a good gun works)

[@britskaradiometeorograph8108]

Definitely agree. I've seen several of his videos about newer weapons and they're always just as interesting as the old and weird stuff

[@aleksanderolbrych9157]

I really enjoy when Ian talks about very fresh, modern guns, a lot of interesting stuff going on right now and it's cool to hear about it.

[@forestcampbell8962]

I second that.

[@RMoribayashi]

The way Ian has often described the inspiration for Forgotten Weapons (as a way to prevent the loss of historic information), I see all but the most mainstream of guns as potentiallly forgotten. Even the most widely known ones have something about them worth adding to this video archive as well.

[@makjak111]

@@RMoribayashi more weird ideas now than ever will be forgotten as soon as tfbtv review video is a couple weeks old and everyone moves on to the next shiny toy

[@spliffburger]

Hearing Ian say "Now here's the special sauce" made my week.

[@zrspangle]

I want that clipped

[@matthewlenhart6607]

Mine was "behoove you" maybe its just the nco in me.

[@ismarwinkelman5648]

This comment deserves 1.82M likes 👌🏾😎

[@GenShark-gh8en]

5:02. For all yall

[@samue1991]

I read this as "made me weak" and immediately thought "you spelled weak wrong but same"

[@oso1165]

I really love when you do firearms that are definitely not forgotten because no one explains the history and the mechanics like you do. Even something as common and simple and plain as a 416 or SCAR or Glock I would love to see you do a video on just because you are so good at explaining the history and why they came to be so popular today.

[@Chris09978]

Oso 11 a military 416 will be very hard to acquire be easier but pricey for the civilian variant btw this is my favorite rifles that was ever made and I want one so bad

[@zacht9447]

The 416 is what happens when an AR15 and an AR18 love each other very much, The scar is what happens when an AR18 and an AK get a little frisky. and the glock is what happens when a plastics manufacturer trys to make a plastic Browning hi power

[@TheBulap]

There is a book on the development and history of the Glock, which is a fascinating read. It doesn't get much into the technical side, but it explains the entire process by which they were designed, adopted, and became so popular.

[@oso1165]

Were just examples. Could be anything. SKS, Remington 700, 1022, etc etc would love to hear the history and development of how they got to be so prevalent. I just hope in general he doesn't shy away from doing popular or common rifles. I find those to be some of his most interesting videos

[@Chris09978]

1423 171 but it’s not really considered an ar it’s considered a battle rifle

[@MBkufel]

I seriously think that Eugene Stoner would be amazed with how little can be done to his gun to totally flip the principle of operation.

[@zmanjace1364]

Hey! Just because it hasn't been forgotten yet doesnt mean it wont be forgotten in the future! Gotta stay ahead of the curve. You never know. Might not be able to find one once no one remembers it.

[@Horseshoecrabwarrior]

I preemptively forgot about this one; I'd never heard of it!

[@vaclav_fejt]

Hudson, sadly.

[@80krauser]

I see you too are a man of culture.

[@marzcapone9939]

It's hard to find one now, gun sales have skyrocketed.

[@CaptainKapitan]

Well in that case I'll see everyone in *25 Years*

[@hyperfocal2002]

ATF: "That guy in Arizona just registered another SBR. What is that 200?"

[@oktayyildirim2911]

I wouldn't doubt it one bit if the people over at the ATF are used to writing out his name at this point.

[@Zapp_Brannag1n]

@@oktayyildirim2911 they actually just have his name on a custom stamp to save time

[@asdfgh9985]

Given how much involvement Ian has with firearms, I wouldn't be surprised if he has his own FFL

[@maestrozero117]

Pre-filled Ian form pdf lmao.

[@pokemaster123ism]

harrylongbaugh1 four, actually. Their full name is Bureau of Alcohol, Tobacco, Forearms and Explosives. BATFE

[@AlexLee-dc2vb]

I think that the Banshee in 5.7mm is a pretty slick idea. It makes FN FiveseveN mags seem more worth their price.

[@johnniewasr5740]

A 5.7 that doesn’t use the 50 round horizontal mags is missing the boat.

[@4skintim962]

@@johnniewasr5740 not really. The point or the 5.7m was to make a low caliber high velocity round that could penetrate soft armor. The p90 only really used horizontal mags due to compactness being a necessity.

[@guyman7776]

If you haven't noticed, they just made one in 4.6x30mm, which is what the MP7 uses. CMMG is really pushing the boundaries at to what the AR platform can fire.

[@AlexLee-dc2vb]

@@guyman7776 I did, but if I was running the company that wouldn't have been my first choice. Relatively speaking, 4.6 doesn't bring anything new to the table (because it's so similar to 5.7) so whether the gun survives on the market depends on how many people want to pay for a pointless and expensive proprietary round, seeing as HK doesn't seem to care about making a civilian MP7 any time soon. I would rather see them make an AR pistol in 7.5 FK and hopefully encourage other companies to put that round into production to bring down its price.

[@guyman7776]

@@AlexLee-dc2vb 7.5 does seem interesting, but that runs into the same problem, another obscure hard to find round. I wonder if FK makes a PCC in 7.5 that ends up being popular, CMMG might make an upper for it and demand for the round goes up and makes more manufacturers interested in making it making it easier to get.

[@oktayyildirim2911]

This is a better commercial for the Banshee than CMMG could ever make. Great video!

[@OttoTheWeim]

CMMG is a stand up company as well. They started with the .22lr conversions and now they give us this. They were very good and communicative with the order process and progress and met their date as to when it would be produced and shipped. By far one of the best PCC out there and their coating leaves nothing to be desired. Everything they make just seems to be quality and to the highest spec. I’m a fan a customer. They didn’t release a half baked product just to let us beta test it.

[@wraithwyvern528]

CMMG has always seemed to me to be the "what if we made an AR do this" kind of guys

[@guytech7310]

In this design the A in AR stands for "anthology" :)

[@kyl3644]

CMMG: "You've seen an AR take AK rounds and mags, now check this .45 radial delayed blowback little boy"

[@jiveturkey2875]

Any company that makes tactical bacon is pretty much a guarantee they're in it because they like what they do.

[@georgewhitworth9742]

Makes sense from a company that once made a muzzle loading AR, lol

[@Mrgunsngear]

I love this system; it really is fantastic

[@jfra9494]

Once again I love that your just another regular gun enthusiast like us and enjoy other guntube channel

[@devinmounce1838]

I wonder how much R&D this actually took.. the fact these changes are so small and subtle makes me think they shot till it failed, made minor tweaks, and tried again till it worked. That’s assuming they planned on keeping the original bolt design. It probably would have been easier to just go with a completely different design.

[@austinm.9832]

@@devinmounce1838 well we got computers now, so they would've used those as much as possible.

[@arctic3032]

Sounds amazing, being able to customize the bolt is ingenious.

[@marc-andreservant201]

It's a remarkably simple idea. The bolt face rotating moves it slowly backwards but attempts to move the much heavier bolt carrier very fast backwards, which means it has to fight much harder against inertia, so the result is that it takes a lot longer to open the breech. It's like trying to do 0-60 but you have to start in 4th gear. Sure you have the same amount of horsepower but you're at a massive mechanical disadvantage.

[@thisguy41487]

I have one of these I built in .45 and it can handle everything from 185gr high velocity, to heavy low velocity, to even the hottest .45 Super that I hand load with ZERO problems or issues. They really knocked it out of the park with this design.

[@timmccallum7336]

silenced? use any weights?

[@thisguy41487]

@@timmccallum7336 almost exclusively suppressed nowadays. I've got an Octane 45 HD that lives on the Banshee, and I still have the 2oz weight in the bolt carrier from shooting .45 Super. It is superb and I can't recommend it enough. It can run the standard pressure .45 ACP without the suppressor just fine as well with that same weight configuration, but the weights aren't needed for it to function if you plan on shooting vanilla .45 ACP.

[@kimisdaman]

@@thisguy41487 You're running a two-ounce bolt weight? What about buffer weight? I have a three-ounce bolt weight, and am waiting on a seven-ounce buffer for my 10mm Banshee. It functions fine, but the rear edge of the ejection port, rather than the case deflector, is taking a real beating, and CMMG says if the heavier buffer doesn't help, downloaded ammo is the next step!

[@thisguy41487]

@kimisdaman I'm running a standard weight buffer, but 10mm is higher pressure, so the maximum amount of added weight is likely needed. You might consider getting a shell deflector pad to prevent it from beating up around the ejection port.

[@kimisdaman]

@@thisguy41487 The stock, bolt-on deflector covers more of the upper than deflectors integral with the upper, but maybe some additional thickness, so the case never gets to the rear of the port, would help. The manual says a heavier buffer might be necessary for warmer loads, but I'm not running near full-power; hopefully the heavier buffer will do the trick.

[@j.fraley6862]

I saw a recent video of this system in action. The guy didn't go into detail about the bolt carrier or anything like what you do, but he did run almost 5000 rounds through the rifle as fast as he could. He did have some feed issues, but the fact that he tried to melt the barrel, he never did and the fact that he went though that much ammo with very little issues was extremely impressive. He also showed the video in infrared and he got the entire rifle glowing, but it never melted the barrel.

[@charleslowrey9309]

Built a 5.7 x 28 AR pistol with CMMG's 11 inch upper that uses a standard mil spec lower, and their 40 round magazines. Loving it thus far.

[@Ultona]

Have one of the first 20 9mm Guards ever made and it has been great for over 1000 rounds. One big advantage of this system is if you have an existing transferable machine Gun or SBR you can use one of these RDB uppers and it will be way easier on your lower than a straight blow back system. CMMG told me no more wear than a standard 5.56 upper would cause. Straight blowback 9mm tends to egg out hammer pin holes and crack hammer pins. Very interesting video.

[@Guru_1092]

I have no idea what any of what you just said means, but I'm glad you got a good product lol.

[@TheGearhead222]

The blowback system per se is hard on both the shooter AND the gun, as there's VERY little dampening and both the gun and the shooter must absorb the rest of the recoil. The French had significant problems with case head separations on their FAMAS, which Ian covered awhile back. Unlike most gas operated systems, there's no kind of adjustment with blowback designs-they either work or they don't. John in Texas

[@GruntJoe0341]

I may need to snag this, for a PCC.

[@redacted2713]

Wait wat a week ago?

[@Shadow-dy7oh]

@@redacted2713 time travel

[@SecretMarsupial]

maikson wever SCP #3548

[@GruntJoe0341]

Patreon.

[@john-paulsilke893]

You will not regret this gun. The recoil is pleasant unlike my Colt AR9. And I do like my Colt, it runs like a top. But it recoils like my AR in 7.62x39 and is harsh, (but not heavy).

[@Quality_Guru]

Wow - I am blown away about the engineering effort that the development team did on behalf of producing a soft recoiling 9mm AR pistol. I had completely ignored the CMMG Banshee because I had incorrectly though it was another blow back system. They are now worthy of consideration along with the PTR-5 (MP-5 Clone) and the B&T GHM as a best in class PCC. A big thanks for the excellent intel.

[@longiusaescius2537]

Huh

[@johncashwell1024]

I actually came up with the idea of a radially delayed blowback system for PCCs based on the AR platform at about same time that CMMG were developing the Banshee. As part of the U.S. Patent Application process, you must research the active patents to ensure that yours is the first and/or your patent doesn't infringe on another patent. That is when I discovered CMMG had beaten me to the Patent Office. It was a sad day for me, but I wasn't too surprised because, to me, the Radially Delayed Blowback system was an obvious next step.

[@zuhailishufller8046]

Ouch. Kinda felt that personally. When something you think on your own but somebody beat you first with the same idea.

[@jannegrey593]

Sometimes I wish that patents could be shared. At least between reasonable people it might have been possible. I am sorry to hear your story. I hope that you will also leave a mark in Engineering history.

[@soapman8970]

That happen to me too...I wasn't an engineer but sometimes when come out some gun Operation system...I get hammer because found out people already taken that step...

[@jacknickolstine3355]

Dont forget about licensing your shit out. I prefer licensing over venturing because it allows you to keep moving on different projects. Not that venturing is bad just another way to make money on shit you dev. It's also alot cheaper when you let a big dog run with your idea. Idk about you but I don't have the marketing connections like that or the money to run a marketing campaign hahahahah. Just make sure you read the contract with a German microscope and a legal team. You can also retain patent rights and all variation of the product. This is nice if they void the contract and try to fuck you.

[@jacknickolstine3355]

@@jannegrey593 you can license your product ideas. This is technically that hahahahaha

[@machinist7230]

The best part is CMMG has made the bolt and barrel assembly available for those who want to buld their own.👍☺

[@illegalclown]

Dang it Ian, I didn't need to spend more money. I already have enough PCCs, including SBRs, but here I am ordering an upper and mag conversions.

[@lepuuttelu]

CLARIFICATION, Ian! 13:58 "Today they offer this in something like eight different calibers as well as a bunch of rifle caliber guns." I don't think they actually offer the *radial delayed* system on rifle calibers. They do use the Banshee name also for some rifle caliber models, but as far as I know, those actually use gas systems rather than this delayed blowback mechanism.

[@ForgottenWeapons]

Correct, I should have been clearer.

[@lepuuttelu]

@@ForgottenWeapons Let me rephrase that as a CLARIFICATION, then :)

[@bisleyblackhawk1288]

I love mine... I ordered the CMMG 9MM upper to fit on my AR pistol lower...the modified magazines are slicker than a minnow...the system is way more dependable than the blow back bolts with less recoil 👍👍👍 CMMG knocked it out of the park with the banshee 😎😎😎...Mean Arms needs a shoutout for the development of the super slick magazines 👍🙏👍🙏

[@Whitefang8128]

10mm seems like such a great PCC caliber. Glad to see someone has woken up to that fact.

[@innercityprepper]

No love for Hi-Point? :D

[@usernamesrlamo]

10mm seems pointless in an 8-12 inch barrel when you can have the versatility of 300 BLK instead.

[@robbledot7290]

@@usernamesrlamo why not both?

[@PrototypeSpaceMonkey]

An AR-15 in .45 ACP... Gentlemen, we have achieved peak 'Muricaness.

[@IAMAGUNH4XP]

@Protherium Don't forget to add a red, white, and blue color scheme

[@vaportrail226]

@Protherium what if, and hear me out, instead of a lever malfunction button. The forward assist would turn the gas on or off. Then we could run semi or have the lever to run the action!

[@joshuaredhorse4030]

It'll need wood furniture, 50 round drum mags and a modern reproduction of the cutts compensator mounted on the muzzle.

[@1911dawg]

@Protherium It also needs an M1A1 Thompson style charging handle

[@austont1537]

Tim LaFrance designed the M16k in 45ACP in 1982.

[@AverageJoe4063]

CMMG has come a long way. I'm not a big PCC fan and I was sceptical at first. It seemed to be a gimmick, but seeing it explained close up it really is innovative. Along with the magazine, getting an upper makes sense as you can practice with the much quieter and less expensive 9mm or even quieter with .45 ACP suppressed for home defense.

[@joshreynolds72]

LOVE, LOVE my Banshee! The radial delay simply must be shot and felt, especially against a straight blowback, to really be appreciated and understood.

[@viniciobrancato4900]

It's cool to see CMMG putting history to work, the whole point of studying it is so we don't commit the same mistakes right? (And because it's cool)

[@Phoenix90384]

Did I miss where he mentioned that the design was based on Mannlicher's M93 semi-automatic rifles? I love Ian's work because he does such a good job researching, but I didn't hear that tidbit thrown out in the video.

[@0nfir34h1m]

I have the 9mm bolt and barrel with the mean arms mags. Feeds like a champ and super soft shooting, especially for a PCC. Its one of my favorite guns.

[@mrkeogh]

CMMG = Clever Men Making Guns.

[@arthurbenedetti9146]

UC = underrated comment

[@full-timepog6844]

@@ALovelyBunchOfDragonballz fbi logging your search history yet?

[@boomwave2]

Cunnilingus muy muy good

[@floo1465]

darksean94 bruh

[@ronmatson5502]

Can't manage making groupcarriers In the first place I just had to wanted to add to hahahaha

[@CenlaSelfDefenseConcepts]

When this came out I thought it was an awesome idea they even sell the bolts and barrels in a kit now so you can build from the ground up with this system I'm thinking about building one on the new WWSD lower.

[@kmostachov]

I like how the carbines's unique operating system really exploits the abundance of AR-15 parts (bolts, mags, etc.) on the market, thus making the gun commercially viable.

[@IWatchedWhat]

Ian, thank you, that was a better description of how that works than most I have seen.

[@ja0298]

I honestly think the CMMG RDB and the endomag is the pinnacle of AR PCC. There is a huge thread on AR15 dot com on the different combinations of buffer & springs to qausi-tune the system to run at different speeds, and more importantly (for me at least) to tune it for suppression. I've shot one of these suppressed and it sounds amazing. I'd like to trade CZ scorpion for one.

[@glasstomouth9654]

I would thoroughly enjoy watching Ian review common modern firearms. No one else gives such an easy to understand demonstration of mechanical function.

[@brkbtjunkie]

Would be cool to see a video on the history of the CZ Scorpion and how it’s changed drastically over the years.

[@arthurrollins6633]

Received my 9mm banshee upper and 9 arc mags in December, absolutely love using it on my ar pistol that usually is chambered in 300 blk.

[@2Potates]

I actually really like how they did the magazine for this thing.

[@AllieStrange]

What a simple yet effective change to the bolt, kinda ingenious really.

[@Sturgeonmeister]

It is amazing how a platform, initially designed in the 1950's, can be so versatile. The AR platform can truly be considered Universal. You have to wonder what the future holds for this platform.

[@KnifingAllDay]

6.5

[@ronroberts110]

I took a deep dive on calibers and decided that the 277 wolverine fit my needs for my first AR

[@patrickriisher1574]

Ar-revoler next?

[@ChuckMorton]

Thanks for doing it. A technical explanation of how the forces are imparted below. The difference in the radial delayed vs direct is that the force from the casing goes through several suboptimal vectors, that reduce the amount of force untimely going backwards on the carrier until the cam is rotated. A simple analogy is pushing a door straight open(blowback) vs pushing at an angle (RDB) at at point the same distance at the hinge both times. The inertia of the door or carrier is dependent on the direction force. The door pushes out on the face, and the carrier only back into the buffer tube, no mater what direction the force is at. 1- The force from the casing goes against the bolt, this push causes the cam pin push back, but can only move at an angle, so the inertia applied to the cam pin from the bolt head is a fraction of the original force. 2- The moment from the cam pin moving then induces a force on the carrier, again not in the optimal position to transfer the force. 3- This dual reduction holds steady until the cam pin is out of pocket and then the force from the casing on the bolt is in a much more optimal direction now, but at this point the peak force has already passed and less momentum has been imparted. 4- At this point both RDB and DBB act the same in with movement, except the DBB has much more moment (1/2*Mass*Velocity^2), and that will transfer to the shooter. The real marvel is using the angled lugs to keep the bolt from staying locked and the spring between the bolt and carrier to induce the direction.

[@tammysilverwolf1085]

Those are some really clever changes, great job engineers. Thank you for the video, Ian!

[@ncgraniteman]

I have become addicted to watching your videos regardless of subject matter. The true hook of almost every video is that as I am asking myself :” how did they do that” you anticipate my question and ANSWER IT!!! From the wall display video to Q & A sessions to weapons history to magazine innovation you have captured my interest and often inspired me to learn more on my own initiative. I do hope to meet you in person some day but until then; Carry on Brother, Carry on!!

[@sixstringedthing]

Operating Systems, Chapter 3 (Blowback & Variations), Verse 09:38: 'And Gun Jesus said to the disciples "bringeth forth thy heavy loads and thine suppressor... But it would behoove thee to contemplate the weight of thy bolt carrier, and add more mass to the ass". And they were sore amazed, and indeed were full of mirth at this lesson'.

[@EarthAltar]

Amen.

[@BarnettEight]

Amen.

[@ColonelPig]

Amen.

[@littledragonstudent2409]

Amen.

[@watchtheworld7840]

Amen.

[@kennynottelling5137]

Thanks, Ian. I actually fully understood how that action works.

[@michaelpee9471]

I would love to see the evolution of the prototypes that ended in this.

[@lepuuttelu]

@Viscous Shear Where's the indication that CMMG ever did anything with an inertia-driven system in the lead-up to this?

[@natebramwell9520]

It is awesome that you always find guns that are uniquely designed some how. No matter there release. Thank you.

[@lathanchurch8352]

Are there any belt fed shotguns, ever? Like in concept, prototypes etc?

[@Paronak]

as far as i know, the only beltfed shotgun i ever saw through a monitor screen, is the automatic heavy machine shotgun from Metro

[@lathanchurch8352]

@@Paronak same, I wish there was a real version but it was made from the dushka heavy machine gun

[@johnm3907]

I seen a rig that had 3 saiga shotguns spinning and firing, it was on that show that was cancelled because the main guy was a rapist

[@marcusborderlands6177]

@@lathanchurch8352 there is one full auto belt fed shotgun on KZbin, but there is literally no information on it

[@marcusborderlands6177]

@@zdub8438 I mean the mk19 is a belt fed grenade launcher, and they have factory buckshot 40mm grenades.

[@Dazrena]

Thank you. You can have a new nickname. The David Attenborough of firearms. You're preserving their history and stories with an enthusiasm and knowledge unmatched by your peers.

[@michaelkolano8686]

you know, i actually wonder how an action like this preforms in automatic fire, compared to straight blowback or even locked breech or roller delayed actions. it being able to use the various different unusual calibers would make it interesting too, i'd like to see how 5.7 and 10mm handle, aside from just 9mm and .45 while not allowed in my state, I've always highly sought after getting one. and this series has been pretty appreciably cited as having a very smooth and clean action with little gas blowback or other disruption. the magazine adapters would mean this could be easily dropped into a transferable lower to test it though.

[@stevailo]

Michael Kolano they actually make both a 10mm and a 5.7mm version of this exact gun, although I don’t think there are equivalent magazine conversation kits

[@its_clean]

Years ago before I learned how the AR's "not really DI" internal piston system worked, I actually thought this is what happened: first the bolt rotates, then it "pushes" the carrier to the rear. I have to assume I'm not the only one who got it backwards. I don't know if this is what motivated CMMG to design their mechanism, but I find it truly inspired and brilliant that they've taken what may be a layman's common misconception, and used exactly that understanding to transform an internal gas piston into a delayed blowback using highly similar parts in virtually the same configuration. Super cool stuff.

[@blue_ridge_shooting762]

This actually a compelling little carbine. The magazine conversion is Uber cool.

[@loupiscanis9449]

Thank you ,Ian .

[@thelastminuteman7513]

This is so cool I love the engineering that goes into these things. I want the 10mm.

[@charlesboots6508]

Ian: "I think it's really clever and cool." Me: "You had my curiosity, but now you have my attention."

[@andrewince8824]

Reminds me of a system used in a prototype SMG, the PPS-42. It used a spiral to twist the bolt as it reciprocated thereby delaying the opening. It never saw service. I'll give you three guesses as to where and when the PPS-42 hails.

[@snape1464]

Really cool PCC. It is one of the first that has the potential to be as good as an mp5, by virtue of not being simple blowback. Adding AR ergonomics and a magazine hold-open, I have high hopes for it

[@TOAOM123]

I got mine in 10mm Recently found out they got em in 5.7x28 and boi am I pickin one up for sure!

[@A-schmuck-on-da-web]

Reminds me of the 1923 Thompson autorifle with a radial like blish lock

[@vaclav_fejt]

@@spraynpray How so? The physics seems sound. And the problem they faced was overcome.

[@76horsepower]

I believe the difference is that, in the Thompson auto rifle, the bolt and bolt carrier move back at the same rate, whereas in this new rifle, the bolt carrier is accelerated at a faster rate at the beginning by the twisting action of the bolt acting on the bolt carrier via the bolt lug in the channel. The Thompson auto rifle is more like the Savage 1907 in that, while there may be a delay, it's simply the turning of the bolt (or barrel, in the case of the Savage) that slows it, not any sort of lever. If the bolt head in this AR was permanently fixed to the bolt carrier so that the two rotated together and at the same rate (if that were possible with an AR platform), then yes, it would work the same as the Thompson auto rifle.

[@jic1]

@Craig Koehler In that it was supposed to be a locked-breach system, and wasn't. But it worked as a delayed-blowback.

[@webtoedman]

@@76horsepower The first Thompsons operated (allegedly) on the "Blish principle". Dissimilar metals under pressure were claimed to stick together momentarily, delaying unlocking until the pressure in the breech had fallen. There was an angled bronze wedge like component that Thompson called the "H piece", which was supposed to do the sticking, but in reality did very little. US Army ordnance deleted it during WW II, making the gun into a simple blowback device, with no problems. My Grandad was very fond of his.

[@76horsepower]

webtoedman My comments are regarding the Thompson Autorifle, the full-power rifle which competed with the Garand, not the Thompson submachine gun.

[@andrewfossatti4937]

Very glad they stuck with it because their radial delayed blowback is as awesome as the H&K roll ser delayed blowback

[@RaDeus87]

11.5 + 3 = 14.5 ounces = 411 grams I can never get my head around ounces, I know it's ~30g, but I just can't do that conversion on the fly like pounds (just halve it to get kg).

[@mrb692]

Jesper O If you want to do even better (1% accuracy be 10%), halve the weight in pounds like you normally do, then subtract 1/10th of the result. So say something is 12 pounds, that halves to 6, and 6 minus 0.6 is 5.4. The real conversion is 5.443.

[@rianrushwood1426]

Jesper O ounces are 1/16 of a pound. Convert to pounds then multiply by 16

[@mitchellpatterson1829]

American here. The secret to the imperial system is hallucinogenic drugs. But seriously, the basis of it is "common" objects used as reference, then fractions for division over decimals. Metric confuses me because I am not used to it. I can convert inches to MM pretty fast, but I worked on cars, so lots of wrench swapping. "Not a 5/8, or a 9/16, must be 15mm" Isn't a kilo 2.2 Lbs? Halving it would lead to some drift.

[@zuzusuperfly8363]

@@mitchellpatterson1829 The only reason I know that a pound is ~450 grams is because we sell meat by weight and people insist on asking for pounds and half pounds. We also have people that ask for shit and leave it in a random isle because the prices are in grams and people have no concept of what a couple hundred grams actually looks like. Literally happens daily.

[@mitchellpatterson1829]

@@zuzusuperfly8363 I worked grocery too. I hate the decorating customers. At least our system is consistent, I have heard horror stories about shopping in Canada.

[@bas6601]

That's pretty cool. Might be a good use for that spare lower I have sitting around.

[@NACAM42]

I have one and it's easily my favorite PCC ever. I recommend getting the upper and the pmag conversion. Not cheap but worth it. Probably like $650 not including the lower.

[@01HondaS2kXD]

Such a cool system. I look forward to seeing your impressions of it at the range. It practically shoots like an MP5, but with the better controls of an AR. And I’m told it suppresses about the same, too.

[@josephfarrah579]

While the firearm is really cool I was quite impressed with that magazine conversion! I've started to have a larger appreciation for magazine design after listening to you talk about it. Often under appreciated and overlooked it seems! Great video!

[@splatmasterxxx]

Having worked on and owned AR platform PCC's that run suppressors, It's an easy 10 thumbs up for the RDB system. If you're tired of eating gas I'd highly recommend buying a bolt/barrel combo. totally worth it.

[@bami2]

I was hoping that was a quad-stack magazine with two rounds front to back and two side-to-side.

[@Celebmacil]

@ADH87 Same as in 5.56mm, assuming the insert isn't built for less for whatever reason. The range available is 10-30, and that's a 30 capacity insert he pulled out.

[@oktayyildirim2911]

That would certainly be a design nightmare

[@sanguinemoon9201]

Quad stack is generally only reliable as a quad stack double feed. This is primarily due to cartridge shift under recoil. Also, for quad feed to function at all it becomes very expensive to make. I'd like to see Schmeisser make one of their quad stacks for this; that'd be quite cool.

[@davidnunez3523]

My friend just built a 40 cal S&W with the cmmg bolt and barrel. People will say that you cant get it to function on a standard lower made for direct blowback bcgs but with some slight modifications to the ejector tab, it functions perfectly. He used an 80% lower with lrbho from AAO as well and it runs really well. The only issue we had with the lower is that it comes with a really weak mag release spring, a stiffer one holds the mag in perfectly. For the upper he used a slick side 458 socom upper. If you want any pointers on building a banshee using cheaper direct blowback lower then let me know.

[@free2chasehappy]

Being an engineer, I love when a company innovates. This is a great design.

[@geicolizard8147]

Shot one of these in 45 only a couple of days ago, first and best time I’ve ever had with a rifle.

[@joelmuller358]

So, any reason that similar magazine inserts couldn't be made inte other calibers mentioned? Would the dimensinons of the AR mag unduly limit the capacity of the bigger pistol rounds?

[@williambell7763]

Yeah, a doublestack 45 mag is pretty wide, its have to be either a proprietary mag, or a single stack, which is kinda silly in a pcc, there are a few companies making specific lowers for the bigger rounds, which I assume would work with the cmmg barrel and bcg, if you remove the extractor from the lower. Edit: I totally missed the actual point of the question, pretty much what I said, but yeah the mags would have to be close to single stack for it to work.

[@mrkeogh]

The mag is very f*cking clever. Why have a dedicated mag when you can switch out the insert so quickly on any P-Mag?

[@owllymannstein7113]

It works particularly well for 9mm because the case head diameter for 9mm and 5.56 is nearly identical. .40, 10mm, and .45 are all larger so the rounds wouldn't stack as well in the mag body and you might have issues with rounds feeding through the feed lips. It could probably be done, but it would take more engineering to make it reliable.

[@theimmortal4718]

357 Magnum???

[@owllymannstein7113]

@max Interesting that you mention 7.62x39, because they do make AR mags in that caliber, and they fit in a standard AR lower. So potentially if one really wanted to you could probably do some funky things with .40 and 10mm

[@RyanLackey]

I love how they were able to do a totally different operating method with such minor changes to parts. Great engineering. I think I'll pick up one of these, just have to decide glock vs. "AR" mag in 9, or a .45.

[@oldman2477]

Ian: "THE SPECIAL SAUCE." Me: ༼;´༎ຶ ᴗ ༎ຶ༽

[@PrototypeSpaceMonkey]

T H E S A U C E kzbin.info/www/bejne/pnLdnYKOfbqJqKc

[@ericb.4358]

Excellent breakdown of this innovative system. Likely the "Radial Delayed Blowback" system wears longer than H&K's roller delay system. There is an excellent reflex sight, the HOLOSUN AEMS, that competes very well with the EoTech sight on your CMMG PCC. The AEMS circle/dot sight has many features: solar panel for reticle when battery dies, choice of circle or dot reticle by pressing the minus button for 3 seconds, automatic OFF after 10 minutes of no movement and "shake awake" ON setting, clear replaceable lens covers, 4 night vision reticle brightness settings (tested to be as good as Eo Tech's settings). PLUSit is less expensive than the EoTech. I have an AEMS on my RUGER PC chassis carbine PCC and love it.

[@pinejungleboogie3563]

I think Forgotten Weapons's comment section is probably the most respectful and decent comment section on KZbin basically the opposite of papa Garandthumb's.

[@cannonroberts5129]

Thank you Ian, I appreciate you looking at different and possibly innovative mechanical systems. After learning you went to school for MET I can now see why are you have such an appreciation for these different mechanical systems.

[@miimatador]

If anyone was wondering what the attachments are. I Muzzle Brake I FSS 11.5” commando barrel I PBX HOLO Optic I Singaurd Stock I SOCOM 10-Round Mag I

[@illusion__5261]

I was just thinking that, however if there was a blueprint that allowed 9mm to look like the 5.56 mag then I'd use that

[@DonziGT230]

I wasn't, but if you're gonna play know-it-all you should state what brand/model brake it is, not just state the obvious that it has one. Also, he gave all the details of the mag; SOCOM was never mentioned and it looks like it would hold much more than 10 rounds.

[@donogruffian2286]

@@DonziGT230 R/whoosh

[@mitchellpatterson1829]

@@DonziGT230 He is referencing a video game (Modern Warfare 2019), and probably had limited knowledge of actual firearms accessories. The actual barrel is 10", not 11.5" (CMMG makes this system in only 10 or 16). The muzzle brake is, well a muzzle brake. The holographic sight is I think an EOTech (Since PBX is a made up brand), the magazine is a 30 round Magpul, and will NOT accept 458 SOCOM. Don't know the stock (it may legally be called an "arm brace") but I'm pretty sure singaurd is made up too.

[@stefanmolnapor910]

Ian, Your the BEST! Thanks for tearing this down, I've been interested in learning about this, but have not had the urge to purchase the gun.

[@austin_bennett]

Gun Jesus has once again ascended into another level: *reviewing guns before they become forgotten!*

[@_ArsNova]

This is fascinating. I'm definitely interested in a .45 SBR upper for my AR-15. Really nice carbine platform for common, cheap, and relatively hard hitting pistol caliber.

[@tobiasGR3Y]

I've been running with one of these in The Division 2... I had no idea this was an actual weapon!

[@harmlesscreationsofthegree1248]

Me too! Just like the LVOA from the first one

[@cheesenoodles8316]

Just under 15 minutes of cool gun engineering explained. I like the refrence to high speed slow motion to diagnose problems....then a video of how the system works.

[@LionofCaliban]

This I need to rewatch a few times. How that action works is still a bit confusing to me. I'll get my head around it eventually. Considering the range of ammunition out there, yeah, I don't blame for taking some time to get it working and loosening up the requirements for operating the gun. They've really done a damned good job, especially if it's available in close to 10 different calibres.

[@regisque]

I'm with you I'm having a hard time understanding this one, but I think I just got it. The force from the angled surfaces is being passed back through the bolt head to act on the cam-pin to force the bolt carrier backwards.

[@bomric1788]

It's like a clicky pen!

[@TheAlex1121]

I watched the AN-94 video about 5 times till I got that one.

[@LionofCaliban]

@@TheAlex1121 Not the only one. That whole thing of the mag being off set by a few degrees and all the stuff going on..... I think I'll need to make it another two three rewatches this weekend.

[@LionofCaliban]

@@regisque I''m starting to get it, the angle surfaces are the key here. Just another rewatch or two and I should have it.

[@timberrecycling]

My favorite videos are like these, where you explain the mechanisms and mechanics of the firearm operating. I've learned so much and before I started watching you I barely understood how guns cycled at all! Thank you!!

[@joshglover2370]

That's awesome how they designed that magazine to work with a standard lower so that you don't have to buy a whole new gun to shoot pistol caliber! 😀👍

[@Oldhogleg]

Reminds me of the blish system. Not in the original operational theory, but in the use of geometric impedance. Not in the original linier form, but radial. That is the initial energy is divided with a portion of the energy being redirected in an orthogonal direction of the initial force, that is redirect geometrically with a beveled bearing surface; causing the needed momentary delay until the impedance had been overcome.

[@Tizzandor]

is it strange, tthat my first reaction to that gun was "aw, that's cute"?

[@GunsNGames1]

Cute lil' AR

[@jannegrey593]

I like Kantai Collection - so to each their own ;) Also this gun looks great - and I am generally not a big fan of AR-15 Aesthetics - it's not ugly, but it's not special. But this one has something.

[@alexanderm3504]

Snorlax

[@Peter-bg5gy]

Hmmm, I venture a guess you have never been in combat...

[@robbeelsas]

**FBI and ATF want to know your location**

[@bigred2989]

I have the Mean Arms conversion for standard blowback AR9s (has an ejector on the magazine itself, the Banshee has one in the lower) and I love it. Works well even after hundreds of rounds.

[@blaisechalmers1464]

I've honestly been waiting for Ian to do a Vid on this beauty 😂🤟🏻

[@brunoratto253]

Not so much a "forgotten" weapon, but a cool, interesting and clever one. I like that Ian isn't all that attached to the concept of the name of the channel. That way we get to see him take a look at these interesting and innovative ideas in firearms developement that we might otherwise miss on account of being so new and *not* forgotten. I for instance had no idea what was the Banshee's gimmick. I thought it was just another PCC. I'm glad to be proven wrong by Ian and learning about this interesting new concept. Radial delayed blowback, huh? Nice!

[@ealtar]

because it's "quasi" locked, i suspect the accuracy to be excellent

[@joshuaredhorse4030]

This radial delayed blowback system with the angled cuts on the rear surface of the bolt locking lugs seems like it would translate over to an AR-18 style of bolt carrier and receiver setup very well. It'd be able to make use of a folding stock due to not having the action spring in a buffer tube and the square bolt carrier would be easy to modify for swappable weights to tune the action. Add the fact that a simple stamped receiver would be cheaper to mass produce and you have an attractive little PDW concept.

[@joelerk6298]

Did you fire this rifle in the #passthemag yesterday

[@redacted2713]

That's right!

[@jackburton7959]

Yep

[@dandel351]

At first I was ready to write this off looking at the thumbnail not realizing it was one of Ian's videos at first . But once I read the title I was thinking I need to see this as I'd never heard of radial delayed blowback before. I can't wait to see the gun fire now. We need a "walking fire" demo like on Project Lightning.

[@TheSchmed]

This, and anything that “looks” like it sooo illegal in NY State (in semi configuration), no detachable mags allowed, except for those who MAKE the laws for us to follow. Their personal protection can have anything they like.

[@devincook2736]

This is a reason why I might join one of the military branches, because in some of the bills proposed ex military would be exempt from the stupidity in DC.

[@chadington6029]

@@devincook2736 Moving to a different location (even just 30 minutes to Virginia) would be a smarter move imo than joining the military for atleast 4 years just to maybe have better access to firearms in DC if you even move back there after serving who knows where.

[@Painterrap]

I'm always waiting on your videos for new products because you really explain all the workings of a given firearm and how it came to be.

[@ravensnflies8167]

04:06 i thought he was going to say "let me show you its features ahh hahh hahh hahh."

[@roguereaver634]

Let me show you what they came up with!

[@sockmon1]

Haa haaa haa haaa, wow! That's a lot of damage ha ha ha

[@michaelmarshall8041]

You're referencing the crazy German with the crossbows and slingshots.

[@sockmon1]

@@michaelmarshall8041 wait, what?

[@foxtail1179]

@@sockmon1 its JoergSprave lol you should check him out

[@troy9477]

Outstanding. Very innovative. Nice to see a company doing the engineering homework to make it reliable, and not rushing it to market just to make money. That magazine system looks very practical too. Now if only i could have any of it in Kalifornia. But i will move to a free state someday in the future.

[@ian-op5fv]

I shocked that there are so many issues with chambering it in 9mm when you have homemade guns like the Sten that work just fine.

[@Hansengineering]

The Sten has that honkin' huge weight Ian mentioned can't fit in an AR-15 pattern receiver.

[@davidburwell4218]

agree seems like they could have gone with a multi-stage recoil spring or something...seems weird

[@steveh1792]

@@davidburwell4218 It's an elegant solution that works very well. And you're not stuck with a heavy bolt slamming back and forth.

[@ronroberts110]

The reason for the delayed blowback is that simple blowback (like the STEN), did not work reliably with the 45 cal. Once CMMG had a patented system, customers asked for a 9mm version, even though simple blowback would work fine for 9mm. Simple blowback would also not work for 10mm or 40 cal, but as to the 9mm, sometimes customers are willing to spend money on something that is un-neccesary, and I cant blame CMMG for profiting off of that. Also, even for 9mm, the SB is not hugely accurate because an open bolt is basically a "slam fire" weapon, and the bolt slamming forward throws off the aim. STEN is very easy and cheap to make, but customers with money seem to like this.

[@dmk0210]

@@ronroberts110 There is a benefit to the delayed blowback 9mm when shooting suppressed. Suppressors increase back pressure. This system delays the bolt longer to keep the gas coming out the ejection port to a minimum and more of it going out through the suppressor. That means it's quieter and less gas in the face. Same with the 9mm MP5's roller delayed system. H&K obviously thought delayed blowback 9mm was worth while.

[@__shifty]

i had a cmmg 9mm convert which had bad feed issues. like you said, i used a high speed camera to find out it was the ugly flat plastic brass deflector they'd put on next to the ejection port. some times the lip of the spent brass would corner dig into the flat face of that plastic deflector and bounce directly backwards, back into the chamber. it was driving me crazy because it would be half ejected stove pipes some times, other times it'd be standard "failure to eject" stile brass in the way. some times the brass would end up back in the chamber completely backwards, primer towards the barrel. took the deflector off, no more issues.

[@jaicanfield5328]

Me watching at 3 AM about to go to sleep Ian: " And here's the special sauce " Me: *go on*