Maxim roller delay AR9 buffer

[alucard0822]

A new entry into the delayed blowback market for PCCs

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

Immediately ordered one, this looks very promising. It uses ball bearings and a wedge to delay blowback. Appears that the initial blowback force is delayed by accelerating the rear part of the buffer mass as it separates from the front part with ball bearings, then looks like it resets with the thin part of the guide rod allowing the bearings to reset inside the rear/outer section of the buffer as it completes it's rearward travel. Hopefully it deals with the problems inherent with others like this of stressing the buffer tube and being really stiff for the first little bit of charging handle movement. Maxim makes really good stuff, and at $189 it is far less than most any other delay blowback conversion system, and even less than the JP SCSS for straight blowback. I have high hopes for this, and own or tried the Scheel, RDB, JP5, blitzkreig and a number of other delayed and straight blowback setups for AR9s. I compete in PCC and have suppressed SBRs, so hoping for less gas to the face and a softer recoil. They have one for carbine tubes and one for their shorter CQB tubes. It requires a 1 peice BCG with weight removed, and so far no short stroke version. Will post soon as it arrives and I can take it to the range to compare to my other AR9 setups.

 

[outrider58]

I'll be waiting to read your thoughts.

 

[teratos]

I have radial delayed blowback and Scheel. So far, I think radial delay wins there. I will also be looking forward to your report.

Alucard, how does the JP compare to the others you’ve tried?

 

[alucard0822]

I have radial delayed blowback and Scheel. So far, I think radial delay wins there. I will also be looking forward to your report.

Alucard, how does the JP compare to the others you’ve tried?

The JP is second only to the MPX in recoil feel. It's a true HK roller delay, and better/faster than most others. The RDB is soft, but feels sluggish to me, the scheel felt good, but has to be tuned just right or it doesn't feel better any than my Blitzkreig comp setup, and is stiff to rack.

 

[teratos]

The JP is second only to the MPX in recoil feel. It's a true HK roller delay, and better/faster than most others. The RDB is soft, but feels sluggish to me, the scheel felt good, but has to be tuned just right or it doesn't feel better any than my Blitzkreig comp setup, and is stiff to rack.

Thanks!

 

[jkeys]

My finger is hovering on the add to cart button. Let us know how this feels/shoots.

 

[calicojack]

My finger is hovering on the add to cart button. Let us know how this feels/shoots.

I know - same here.

 

[John from MD]

I'm not giving up my Banshee - yet.

 

[erwos]

I want to like this, it looks more refined than the Scheel's system, but I also want to read some reviews before throwing $200 at it.

 

[SkiPatrolDude]

If this actually works this may help change my opinion that AR9's are a complete and total waste of $

 

[GuitarmanNick]

I don't see what all the fuss is about.

Every 9mm pistol in my modest collection is direct blowback and I would use any one of them to defend my life.

If you select the correct buffer and spring combination, any AR-9 can be made just as reliable and safe too shoot.

I had some issues with my build initially, but after changing the buffer and spring, it runs perfectly even when fast firing.

 

[teratos]

I don't see what all the fuss is about.

Every 9mm pistol in my modest collection is direct blowback and I would use any one of them to defend my life.

If you select the correct buffer and spring combination, any AR-9 can be made just as reliable and safe too shoot.

I had some issues with my build initially, but after changing the buffer and spring, it runs perfectly even when fast firing.

The problem with the AR-9 is all the weight in the buffer and BCG. It creates far more recoil than an AR in 5.56.

 

[John from MD]

I don't see what all the fuss is about.

Every 9mm pistol in my modest collection is direct blowback and I would use any one of them to defend my life.

If you select the correct buffer and spring combination, any AR-9 can be made just as reliable and safe too shoot.

I had some issues with my build initially, but after changing the buffer and spring, it runs perfectly even when fast firing.

It is not about reliability as blow back is about the most reliable you can get. I can assure you that MP40's, Grease Guns and Stens are really reliable. However, they are also heavy. Blowback AR's are heavier than they need to be when made as a blowback. They also have a more pronounce recoil moment due to the heavy bolt.

Delayed blowback AR's are lighter and you can get back on target faster with them. Add a fast trigger such as a Rise Armament and you can put more bullets down range, in a tighter group that with a pure blowback AR.

 

[GuitarmanNick]

The problem with the AR-9 is all the weight in the buffer and BCG. It creates far more recoil than an AR in 5.56.

I will never complain about the recoil on my AR-9 after shooting Mosins and short barreled .30-06 rifles. Yes, it is more than a 5.56, but still quite manageable for an old man.

People these days are too soft!

Delayed blowback AR's are lighter and you can get back on target faster with them. Add a fast trigger such as a Rise Armament and you can put more bullets down range, in a tighter group that with a pure blowback AR.

My AR-9 is accurate out to 100 yards, easily. No need to send lots of rounds down range fast if the first one or two does the job. Gotta be aware of ammo use when in a gunfight. Nothing worse than running out of ammo while still facing a threat!

If you are competing or perhaps have shoulder problems like my dad, then I can see doing some upgrades to reduce recoil. Managing recoil is part of shooting and can be mitigated to some degree with proper technique.

If your mechanics are right, putting follow up rounds on target should not be a problem. Those experiencing difficulty staying on target while firing should work on their skills before blaming the gun.

 

[ken792]

I will never complain about the recoil on my AR-9 after shooting Mosins and short barreled .30-06 rifles. Yes, it is more than a 5.56, but still quite manageable for an old man.

People these days are too soft!


My AR-9 is accurate out to 100 yards, easily. No need to send lots of rounds down range fast if the first one or two does the job. Gotta be aware of ammo use when in a gunfight. Nothing worse than running out of ammo while still facing a threat!

If you are competing or perhaps have shoulder problems like my dad, then I can see doing some upgrades to reduce recoil. Managing recoil is part of shooting and can be mitigated to some degree with proper technique.

If your mechanics are right, putting follow up rounds on target should not be a problem. Those experiencing difficulty staying on target while firing should work on their skills before blaming the gun.

When trying to shave hundredths of a second off splits on target and doing target transitions, it doesn’t seem many competition shooters choose a straight blowback 9mm AR over other offerings if they can afford them.

 

[teratos]

I will never complain about the recoil on my AR-9 after shooting Mosins and short barreled .30-06 rifles. Yes, it is more than a 5.56, but still quite manageable for an old man.

People these days are too soft!


My AR-9 is accurate out to 100 yards, easily. No need to send lots of rounds down range fast if the first one or two does the job. Gotta be aware of ammo use when in a gunfight. Nothing worse than running out of ammo while still facing a threat!

If you are competing or perhaps have shoulder problems like my dad, then I can see doing some upgrades to reduce recoil. Managing recoil is part of shooting and can be mitigated to some degree with proper technique.

If your mechanics are right, putting follow up rounds on target should not be a problem. Those experiencing difficulty staying on target while firing should work on their skills before blaming the gun.

I get it.

Though if you can take a significant amount of weight out of your gun AND have significantly less recoil…why not?

 

[kenpo333]

Just one qustion: What does Chad say?

 

[Bountied]

So with the bolt weight removed and the 5.5oz buffer substituted for this one what will the weight savings be? Looks interesting for sure.

I have a CMMG and next to my direct blowback I did not notice a huge reduction in recoil. I think I need to dual wield to be able to truly tell.

 

[alucard0822]

I have been talking back and forth with their tech / R&D folk about some things, so hopefully something comes out of that. Still waiting on mine to arrive, but I'll slap it in and try it out soon as it gets here.

As far as "why delayed blowback?" Direct blowback basically uses the brass as both the locking mechanism and piston to cycle. Fire it, and the case expands, lock in the chamber through pressure/friction, and when pressure drops enough for it to slip, it "blows back" against the bolt face to power it. Once enough gas leaks between the brass and chamber, and out the barrel, the inertia of that short 1/4" or so powered movement completes the cycle. The bolt mass more than anything dictates bolt velocity, and tends to be 24oz or so with a heavy spring. The downside is that it takes a lot of weight, and that increases recoil and dot movement, the load pressure, chamber specs and differences in the friction of the brass in the chamber can change things. There tends to be a lot of gas blowback, especially in 9mm with the tapered case unsealing the chamber as it starts blowing back, this adds port pop and gas to the face, especially when suppressed.

Delayed blowback simply adds a mechanism to offer mechanical advantage to the buffer or carrier mass. During the 1/4" of movement during blowback, a system like this or HK's uses a wedge and rollers or bearings to accelerate the carrier more than the 1:1 a blowback system has. Being force is basically acceleration X mass, if you have a greater ratio of linear movement, then you need much less mass to give the same resistance, and achieve the same reliable bolt velocity. Basically the greater acceleration of the mass during the powered part of blowback operation increases the resistance to more closely match the forces of the brass pushing against the bolt face. Less reciprocating mass = less recoil, less dot movement, and less gas in the face. Of course the added complexity may not be as "reliable" as a simple direct blowback, but they can be extremely reliable compared to gas or recoil operated systems.

As far as "$200 for less recoil, and less gas in the face, are you a Biatch? " LOL OK boomer. My AR9s are for fun, competition, shooting suppressed, usually shooting steel plates fast and close, faster cycle with less recoil = better splits and better stage times. Shooting suppressed, gas in the face and port pop ringing my ear sucks.

 

[alucard0822]

So with the bolt weight removed and the 5.5oz buffer substituted for this one what will the weight savings be? Looks interesting for sure.

I have a CMMG and next to my direct blowback I did not notice a huge reduction in recoil. I think I need to dual wield to be able to truly tell.

My blowback BLitzkreig short stroke competition setup was $165, and weighs 8.5 oz with the BCG weight in. It has really light and smooth recoil, cycles fast, the short stroke cuts down on gas to the face, very little dot movement once I got the right spring setup.

My range/prior competition setup was a 10oz buffer with floating mass and short stroke springs/cushions, probably $80 or so in parts, actually softer/smoother than the Blitzkreig, but a little slower, and more dot movement due to the greater mass.

The maxim delayed recoil system is 8.3 oz , but without the 2oz BCG weight, and appears it includes the spring in the weight spec(usually about 1.5oz), the others don't. So basically like a 4.8oz buffer, saving 4 or 5 oz, which isn't huge, but it's reciprocating mass, which is extremely noticeable when shooting. Still have to see how it feels, and if it's reliable enough for PCC competition.

I have shot a few CMMG RDB setups. The delayed blowback does make recoil feel as soft or softer than a really good blowback setup, but the long stroke and light springs make it feel sluggish. They seem to have reliability problems, and the feed angle/height is a little different than most blowback AR9s, so some lowers have to be modified on top of removing things like blowback ejectors and LRBHO mechanisms.

I finally got to try a Scheel a couple months ago, fellow competitor at my home range was testing it, and got to trade some rounds through my Blitzkreig setup for his. It did reduce recoil for the given buffer mass, but IMO isn't true delayed blowback. Roller delay adds leverage to accelerate the BCG or buffer mass at more than a 1:1 rate compared to the bolt face, that greater acceleration of mass is what increases resistance. The Scheel wedges the rollers in cutouts in the buffer tube with spring pressure, but is still moving the mass 1:1 compared to the Bolt face, although the lighter mass does give less dot movement than my heavier blowback system did. It made the charging handle hard to rack being you have to fight the same spring resistance to charge it. The cutouts in the buffer tube seemed OK, but looks like clothing or dirt getting stuck in there could cause problems, and there was some fouling coming out of it. While it felt as soft as my Blitzkreig setup when I shot it, he said it wasn't as good as my hydraulic blowback setup till he spent time tuning the springs and ammo load.

The Sig MPX is a gas piston design, I shot one, and it was instant love, the recoil is stupid light, no need for a buffer tube, short fast stroke, and it feels awesome. Only downside besides the $2K price and $65 mags is reliability, they got popular fast in competition, then kinda went away due to poor reliability, they get dirty fast and choke, they are also ammo sensitive.

So far the best flat out is the JP5. got to demo one, it's basically as light as the MPX in recoil, 0 dot movement, GLOCK mags, quick short stroke cycle, and so far most find it reliable. The different wedge angles and springs make it tuneable. It is the best PCC for competition currently made, and for $3300 it should be.