I hear you...  as mentioned in my post above, I was disappointed that we didn't get any pictures of what these rails look like that the carrier rides on....so I'm speculating that maybe the reason that they didn't do a BCG/Barrel combo is that maybe the receiver has some kind of grooves or something that the rails need to interface with.

It is expensive but for someone that really wants the creature comforts of the AR15/M16 platform and a 'mechanically' tuneable delayed blowback system.  It is the only game in town.
Yes, there is the CMMG RDB that I've written a ton about but the only real tuning the company offers is adding weights to the carrier which just makes it more bouncy.
I'm really hoping the MEAN Arms will be released and if it works as good as I hope then the only real competition to it other than a highly tuned CMMG RDB (like I'm running) will be the JP-5.
Now the JP-5 uses HK locking pieces and rollers and from all accounts looks outstanding....however it uses a proprietary receiver length (distance between the front and rear take down pins is shorter) so you MUST buy the complete gun which starts at $3200....
So a $1500 upper isn't crazy compared to that.

Also note that the JP-5 is Glock mag fed only and I personally don't care for Glock mag's in a SMG.  

The MEAN Arms is also full auto capable (not that many care about that but I do) and the JP-5 is not since the ejector design is right where a RDIAS/RLL would need to go and I did confirm with JP that it would not work.  I would have bought one if it was FA capable.

I remember MEAN saying that the reserving an upper would also help them gauge interest.... I really hope that they don't come back saying, "Not enough interest and not going into production!"  That would be a huge bummer.

Don't get me wrong Amphibian, I'm definitely interested in it and I'm really excited to see something come out that isn't insanely proprietary or is generic blowback. That being said, I'm just not sure I am ready to spend $1500 bucks on it to find out it will not work with my SBRed S9, Colt, or ARV lowers. In the end I hope these guys sell a ton of them, but I have my concerns about the cross-platform compatibility they spoke about in the initial posting. Once they finally deliver yours and you get down to the nitty gritty of it, I'll look into ordering one for myself. I think Droppoint said he had reserved one as well. Any word as to when you should expect delivery? Also, I don't see them pulling back now, they've already had publication articles written about it and so on, seems that would be a silly move business wise, but what would I know.

Anyway, Thanks for the reply! It is always great reading your written thoughts.

I’m only expecting this upper to work with a bone stock lower and endomags.

That’s my expectation.  

I’m hoping it’ll run on a RR, potentially a lower with a rLL (which means a modified BCG), maybe Glock mags and maybe Colt mags (with appropriate mag well).  

However, my expectation is a requirement, and that seems to obvious.

Same, my expectation is lightning link, so proprietary return springs (like the MCX, or the BRN-180 or whatever it is) are a no go, and the bolt as pictured, the tail looks perfectly fine to run on a RR or DIAS and looks like I can cut it down like normal for my RLL. I also want it run on Colt mags preferably. MP5 wouldn't be bad, then Glock, then last resort endomags. Nothing against them, but the wasted space offends me.

I was notified shortly after getting on the pre order that I was the first pre order.  5" I think

Can't wait!



It'll get tossed on a FA lower and beat on

This is great! I cannot wait to read your thoughts pertaining to it gentlemen. Keep us informed!

Oh, and let us pick the hand guard length on the upper! So I don't have to immediately replace the hand guard to go over my can!

They told me I was in the first 20.  Website still says, "Expected to begin shipping late Q1 - early Q2"....so hopefully anytime now...

I will test with Colt, Endomags and Glock.  I may also test with Scorpion mags which I prefer over MP5 mags for LRBHO.

Please do a 1.85" inner diameter polymer molded MA handguard for the DA Wolfman! Other good sub gun cans cans are 1.5" but the Wolfman is the biggest and quietest at 1.62". I would like 0.100" clearance all around the can. The problem is the Wolfman is it's fat and doesn't fit inside anything except for Smoke Composites carbon fiber tube handguard. But the lack of a sturdy top rail and no Mlok/snap-in rail cover options for hand traction leaves a lot to be desired with the Smoke Composites tube. A fat MA polymer Handguard is exactly what is needed with tucked cans for heat mitigation/burn safety while still hanging a light off the front and attaching MLok traction panels. I have used Lancer's carbon fiber handguard but the Wolfman doesn't fit, skinny pistol cans only.
Why do I think MA NEED's to do this? Cuz straight blow back sucks and I have been waiting for a proper designed delayed blowback system with AR Ergonomics and training familiarity (Endomags are perfect for this) for years now. Got high hopes for the bearing delay. Delayed blowback is lighter recoiling, quieter with less port-pop and less gas-to-face. Using a 4.5" 9mm barrel and a tucked sub gun can I can have suppressed subsonic expanding projectile capability at a fraction of the cost of machined .300blk ammo all with the same total length of a MK18 10.5 556mm unsuppressed or about the same overall length as a 5.5" 300blk AR with a decent can but at a fraction of the cost.

CF would make more sense than polymer due to heat transfer.

How we looking on this? By my counts we are into late 2Q!

Meanwhile, Maxim took my idea

Attached File

What is this thing @RDTCU

https://maximdefense.com/product/244978/

Maybe I missed it, but does this thing have LRBHO?

Yes.  Look at the first page of this thread and see my post where I put a link to a Shot Show range day video that I uploaded to my site.  It is run in full auto and you can see it runs dry with LRBHO.

Thanks.

Was wondering the same thing. I see videos for this on youtube where the guy is demo'ing it at IV8888 range day from 2021 and it is now almost two years later.
Hopefully this isn't like other companies empty promises that turn out to be vaporware and it never makes it to the market.

I'm not a technical person but at a glance that seems like a pretty clean solution.

I created a thread for the Maxim RDBS here: https://www.ar15.com/forums/AR-15/Maxim-Defense-RDB-review/15-780933/

+1....I wish I was wrong about it not making their shipping date.

I sent them an email asking for an update since we are officially in Q3 now.

Get a response yet? Just curious.

Unfortunately, no response...

Wow... I never expected Mean Arms to take this long. I'm wondering if they've uncovered a problem or something, or are nitpicking to make sure its perfect.

I did speak to Tommy at MEAN briefly on the 8th and he mentioned something about adding a coating to the uppers and wanting them to be perfect.  I told him it would be nice if someone would provide some kind of updates and he said he would see what he could do and ask some guys...

Tommy just called me for the remainder of my deposit and he is saying about 10 days out!  So looking forward to this!

Tommy called me as well, for the same reason, and said my 11" upper would ship within 30 days. Might be a difference in timing due to configuration, (barrel length) or hopefully, "under-promise, over-deliver." Either way, very excited that MEAN is rolling our uppers out!

Any update Amphibian? I'm like a kid at Christmas here.

They told me last night it would ship today. ...but I haven't heard anything  today

So they came through....got an email with tracking and scheduled to be here on Monday!

So received the upper today and will be taking my time to do some more documentation before shooting it.
The manual is quite extensive and impressive with all the detail.

The preventative maintenance schedule is what I find the most disappointing.




According to the manual you need to get PM Kit 1 containing the ejector spring, extractor spring and ejector retaining pin every 2500 rounds for suppressed and/or full auto.  
I have reached out to MEAN and was told that these numbers are VERY conservative.
Even if you double those numbers and say you need to replace those parts every 5K or quadruple them at 10K, you never have to replace the ejector on a straight blowback 9mm AR and I don't think I've ever replaced the extractor in the bolt of my 9mm Colt SMG bolt.  Granted straight blowback won't be as smooth as this (hopefully).

Then you need to replace the bearing retainer ring and bearings at 10K or (5K).

I asked if they had any way of gauging the spring health instead of documenting round count and they said no...
So like the CMMG RDB in which I measured the spring strength I have done the same here:





Now regarding the bolt gap below is what the manual states.



I measured mine and it seems out of spec:
Manual states needs to be 3.84 and 3.855
@MEAN_Arms please comment on my bolt gap???


Below in red is where I measured to which should be the bolt extension from the rear face of the carrier.


I plan shooting suppressed so I removed the muzzle break which requires two 21mm wrenches and the break is reverse threaded.  I felt this was all overly complex which everyone shooting suppressed will just end up not using.  One of the appeals of this upper is as a suppressed platform and the break isn't suppressor compatible so it seems to be a waste for someone like me.
The chamber is fluted and having an integral 3 lug would be awesome.
Picture I took of the fluted chamber


A reaction rod won't work for this upper due to the proprietary extension and didn't want to risk any damage to the upper so instead I decided to remove the rail to get better access to the muzzle.
I stripped the head of one the allen head bolts trying to get it out and had to use a screw extractor to remove it.

Also for those wanting to run in FA, dry cycling it seems to work fine with a RR and a RDIAS although the lug is a little on the wide side.
I didn't take the rail locator out yet but it looks like it will interfere with a RLL.  NVM...I was thinking about the RLL wrong...should be fine with a RLL assuming you mod the carrier

I just got off the phone with some of the guys at MEAN and apparently I received a manual that was misprinted.
The bolt gap range should be 3.855 to 3.87 so my unit is within tolerance.

They also told me that they are trying to be very conservative with their round count maintenance estimates and I will be very pleased with how many rounds it can go....so we shall see.  
I don't plan on replacing any springs until I have a failure.

There happens to be a SMG match this weekend.  Not sure if I have to work this weekend or not yet.  If I don't have to work, then I hope to run it in the match and I usually run around 500 rounds per match.   Suppressed and full auto.  I hope to obviously test it a little before the match as well to figure out what buffer / spring combo I will use and get some cyclic rate data.

Uh oh. Bad news for me.

And as an aside, how much in scrap $ do you think that chonking brake is worth? I think just downloading the picture made my laptop heavier.

I fixed my post above...I forgot the RLL goes behind the lug so should be fine.
Don't know how to comment on your post regarding the brake...lol

This is great information Amphibian. I cannot wait to read about the match and how the weapon functioned under some stress. Thanks for this!

I see you are in FL.  The SMG match is on Sunday in Port Malabar.  PM me if interested.

Some more pics / thoughts:

Thank you.

Oh regarding Colt mags...I saw this in the manual:


I took out the magwell that I setup to run Colt mags with my CMMG RDB setup as discussed on my site here: https://c3junkie.com/?page_id=374
I believe that in order to run Colt mags with this setup you need to do similar mods.  I think the 'ears' of the feed ramp block of most Colt mag well adapters would interfere with the rails.

You can see in my picture below that the mag cannot go any higher or it will hit the rails.  Even at this height you can see if the round isn't presented 'square' to the feed lips and at an angle like this, the bolt will go over the rim.
I am curious what Colt mag setups MEAN has tested to work.

Manual shows that there should be two 'secondary firing pin springs' that are really spring washers but mine came with only 1 flat washer.

The length of that firing pin...

Is the chamber further forward on the Mean than on a standard blowback AR-9?

Yes, but I would think that is obvious since a standard blowback AR-9 doesn't really have an extension.  With those barrels, the extension area is part of the barrel...in addition a standard AR-9 also uses a different FP than a standard AR...
I'm thinking that you were maybe thinking of the difference between a CMMG RDB and this?  In which a CMMG RDB does use standard AR firing pins.
So yeah, comparing a CMMG RDB or standard AR, the chamber is further forward as you can see in my picture below that the bolt goes further forward.

To be clear, are you saying the MEAN bbl has an extension?  A separate part that is attached to the bbl aft of the chamber?

Yes, it's what the bolt head locks into.
Same function as the trunnion of an MP5.

Right this older article has a good pic of the extension: https://www.thetruthaboutguns.com/shot-show-roller-delayed-blowback-ar-9-from-mean-llc/
https://cdn0.thetruthaboutguns.com/wp-content/uploads/2022/01/20220119_110503-scaled.jpg

Ah, figgered it was running the rollers against the receiver, I suppose steel on aluminum would be bad.