As we ramp up our production capabilities, it's important to get the word out about the Bearing Delay Upper Receiver.  The system is now live for purchase on our website.

If you want to skip what we have to say and read about consumers shooting it, go see @fullauto01 and his review thread.  Also, @amphibian has shown the adaptability of our system to different buffers and custom ammo in our thread in the Industry Section.



This product has been a long time coming and we know that there has been some hype in the past and that people have been disappointed that it has taken so long.  This system is our take on modernizing and improving roller delay systems.  After years of fielding service calls and helping customers get 9mm ARs running with Endomags we did not feel that blowback 9mm systems were safe enough.  So we wanted a safer system, and we wanted to maintain all of the advantages of a roller delay (durability, reliability, low recoil) and eliminate or at least mitigate the disadvantages while also maximizing compatibility with the AR platform. In our view, traditional roller delay was too heavy, too expensive, and too German (complicated).  We also believe that past attempts to incorporate roller delay into the AR world were too literal.  Trying to put MP5 rollers (square peg) into the AR platform (round hole).  We actually started out with cylindrical rollers, which is what we showed at SHOT in 2020.  In some ways this system was incredible and our prototypes ran really well. However, we ultimately decided that this system raised some manufacturing issues.

So we did a Crazy Ivan and began anew.  We replaced the 2 cylindrical rollers of the old roller delay systems with 3 ball bearings.  Each of our ball bearings has the same contact surface area as the original MP5 roller.  So with our 3 bearings, we have 50% more contact surface area than a traditional roller delay.  Our barrel extension includes 3 machined pockets that correspond to the 3 ball bearings.  Because our barrel extension is simply threaded onto the barrel, it can be removed/replaced, unlike the old MP5 part that is pressed into the sheet metal receiver.  The system is designed to work with a standard AR-15 5.56 buffer (carbine, H, H2, etc.) - no 9mm-specific buffer needed.



The system works in a standard AR-15 milspec upper receiver. Our test mules used standard off-the-shelf uppers (with forward assist) but the production models are billet slick-side uppers (more info below). The system is compatible with standard AR charging handles and handguards.

For the lower receiver, because of the Endomag, we started out with milspec AR-15 lowers (and this is how most of our testing was conducted, including full auto).  The system is also compatible with dedicated pistol magazine lower receivers.  The only caveat is that most of these receivers include a stationary ejector in the lower - this ejector will need to be removed for the Bearing Delay Upper.  Most of our testing for pistol mag lowers has focused on Glock magazine lowers.  See the far right setup below, which is using a CMMG Glock lower.



We're selling the Bearing Delay Upper Receiver as a complete upper receiver system ready to be paired with the AR lower receiver of your choice.  5 different barrel lengths: 4.5", 7.5", 11", 14.5", 16" - all threaded for a 1/2-28 muzzle device.  There is an option to have the muzzle device for the 14.5" barrel permanently attached.

The heart of the Bearing Delay Upper Receiver is the unique ball bearing bolt carrier group.  The ball bearings interface with corresponding features in the barrel extension and provide the lockup in battery and the delay after firing.  The system can be tuned by replacing the Lifter to change the angle of the surfaces that push the bearings from the inside of the BCG.  The bolt face includes our unique center ejector to provide the most consistent ejection of any 9mm AR on the market.  The firing pin passes through the ejector.



The ability to tune the system by swapping the Lifter means that the Bearing Delay system can be tuned based on ammunition type, barrel length, suppressor, or any other factor.  Each Bearing Delay Upper Receiver includes 2 Lifters - one in the BCG and a second in the box for tuning. Other Lifters will be available for purchase from MEAN.

The Lifter that comes installed in the BCG will be a swiss army knife designed to work with 90% of the off-the-shelf ammo on the market (i.e., most 115 gr to 147 gr). There will be a second Lifter included.  MEAN will be careful about recommending the second Lifter because a Lifter designed for lighter/slower ammo, if used with hotter ammo (+P, +P+, etc), may cause the system to cycle faster than preferred.  Additional Lifters are available separately that will bridge the gap between the swiss army knife OEM Lifter and the second Lifter.



We expect to have some customers that never swap the Lifter and shoot the OEM option forever. We also expect some folks will want to tinker and swap Lifters after almost every round.

Different Lifters will allow the user to slow down or speed up the cycle time for the firearm - almost like changing a cam in an engine. Slowing down the cycle time will also reduce the perceived recoil, but eventually slowing the system down too much will cause cycling problems (i.e., not enough energy to push the BCG back and pick up the next round).  Adding buffer weight can also slow down cycle time.  From a customer service perspective, MEAN will be careful about making sure that users who are already cycling fast do not start reducing buffer weight.

In some cases, our support department would want to discuss your setup with you before providing specific recommendations.  Swapping a Lifter is the best way to affect dwell time of the system because it allows the user to directly mechanically affect the operation/delay after firing.  But, we also recognize that many users will already have the ability to tweak buffer weight, and this can be an effective variable for tuning the system as well.

One of the most common questions is: "Can I buy a separate BCG/barrel parts kit and make my own upper?" - The answer is not yet, but possibly yes, in the future.  We pride ourselves on our level of customer service and attention to detail so, for the short term, we want to have complete known systems in the wild.  The number of lowers and buffer systems on the market are already enormous for us to consider from the customer service perspective.  There is always the option of buying the complete upper and swapping parts.  Our system includes two rails that extend rearward within the upper from our barrel extension.  They fit in standard milspec AR-15 upper receivers.  The system is compatible with standard AR charging handles and handguards.

The Bearing Delay Upper is covered by our Lifetime Warranty (original owner or not) so we will always fix (or if necessary replace) the product.

Each Bearing Delay Upper Receiver includes 2 Endomags.  We make 2 different Endomags: (1) the original Endomag includes an ejector and is compatible with most blowback 9mm systems and (2) ejectorless Endomag, which works with this system and with CMMG's radial delay 9mm system.

MA Upper Receiver
The Bearing Delay Upper Receiver includes a slick side billet machined aluminum upper receiver that adheres to milspec standards. No forward assist.


MA Handguard
The new MA Handguard is a free float hybrid design including a very rigid high temperature and high strength polymer body with a metallic insert that is overmolded (permanently attached) within the handguard and threads onto the specially designed barrel nut.

Internal width (flat to flat): ~1.375"
Available in 5 lengths based on the barrel configurations of our Bearing Delay Upper Receiver.


We ran a setup with a suppressor inside the Handguard at SHOT Range Day 2023 with a Surefire RYDER 9TI (about 1.25" OD).  It was our 4.5" barrel and we used the handguard we usually put on our 11" barrel upper (see below).  No issues with heat.  No one even needed a glove because polymer doesn't absorb heat like aluminum does (see below).



The polymer material we chose for the handguard is not common and is specifically designed for high temperature and high strength.  It is not common because it is expensive and difficult to manufacture.  However, keep in mind that the people that started MEAN have been in the injection molding industry for 50+ years.  We don't have any reservations about using the handuard with any PCC system (full auto, suppressed, anything).  Someone took a thermal video of Eric (IV8888) in October 2022 shooting the Bearing Delay full auto at his range day with a prototype of the handguard.  That gun had been running virtually all day with lots of full auto.  As you can see below, he is holding the handguard with his bare hands.  The barrel is very hot in the video but the handguard is cooler than the magazine.  Polymer is an insulator and doesn't absorb heat like aluminum does.



MA Charging Handle
The MA Charging Handle is a new ambidextrous design incorporating both steel and aluminum machined components.


MA Muzzle Device
The new MA Muzzle Device reduces recoil and muzzle flash.  Comes with a left-hand threaded jam nut which eliminates the need for a crush washer.  Note: those selecting a 14.5" barrel upper will have the option to select whether the muzzle device should be permanently attached or not.



The initial release for the Bearing Delay system is obviously 9mm, which makes sense given our history with the Endomag.  What calibers does the community want for bearing delay?  More PCC calibers?  Rifle calibers?  ...

They're pretty simple.  The main consideration is to make sure that the ejector is removable - it needs to be removed to avoid interfering with our BCG (there is an ejector built-in to our BCG).  The Stern Defense is a good choice.  The Bearing Delay upper also works with dedicated pistol mag lowers, if you don't want to mess with a conversion block.  And, of course, there is the Endomag if you want to use a milspec lower (choose Ejectorless for the Bearing Delay system).  Each upper comes with 2 Endomags.

Yes, definitely FA compatible.  Much of our testing is done in full auto.  The ejection pattern animation above is full auto.

So is this:

Thanks man!

Thanks - we think so too (possibly biased)

Definitely less gas compared to a blowback.  The dwell time or delay can be adjusted using our Lifter (changing the angle for the mechanism) and with the buffer.

Thanks for buying the Upper!

For the EndoMag, make sure it is the ejectorless version (there will be 2 new ones included when you receive your upper).

For the buffer and spring, there are tons of variables that can affect it.  For example, the answer definitely depends on the ammo you're using.  We designed the upper to work with a standard carbine buffer and spring.  The next most common buffer we use in testing is the H2.  We believe that one of the benefits of the Bearing Delay system is that you don't need to buy expensive buffers or other accessories that might be needed for other PCC systems on the market.  Of course, some people already have that stuff sitting around.  You have posted in our thread on the Industry Section so you have seen that @amphibian has used hydraulic buffers and Tubb flat springs with our system.  We have tested similar setups.

We'd be happy to discuss your particular needs/wants - just reach out to us (email/phone/DM) and we can set up a meeting with our engineering team to discuss with you.

Thanks!

The charging handle pulls on the U-shaped cutout in the top of the carrier (see animation below).  The Bearing Delay system is compatible with normal AR-15 charging handles so our CH can be swapped out if you have another one that you prefer.

Here is an animation for disassembling the BCG for Depot Stripping Level 1 for detail cleaning or to swap the Lifter (to tune the BCG).

That is in the works.

Black Friday 10% off everything - including the Bearing Delay upper

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