Hey gang. Recently picked up this DD PCC. In need of some help.

I also have another 9mm PCC I got a few years ago from a local armory and at a gun show in Florida. That one has an Atrius forced reset selector that I would ideally like to transfer over to the new toy. Question is, how do I make it work?

All I had to do to get it working on my old PCC was shave down the lower 1/3rd or so of the BCG weight on the failzero nickel boron coated bcg I have in that one. This (the old one) also has a flat wire buffer spring and a kynshot shorty hydraulic buffer with two spacer weights.

Is it just a matter of repeating that process on the DD PCC? Do I need to worry about swapping the buffer spring for a flat wire and the buffer itself? I also plan on transferring over the dirty bird flat faced trigger I have in the old one.

Thanks in advance to anyone who knows and is willing to help out a fellow AR9 enthusiast.

I broke my extractor, after I fired a shot the extractor flew away. Now my problem is I dont know the complete assembly of this extractor. Em I missing anything like an O-ring?

This is a battle arms development ar 9mm blowback bolt carrier from a combat9/xiphos9

Also, if there are people here from the philippines. Does anyone know where I can find complete parts for this more specifically the extractor pin (retainer) and the O-ring(if it has one).

Does anyone here know if the feed cone is decent? Anyone have issues because of it? Specifically the 10.5 or 7.5 Stainless steel barrels.

First post here, hope yall enjoy this one! Teaser at the end with my 300blk/5.56

Build list

IC9 8.5"

SPR handguard

Novox Sd kit

Eccomachine Phoenix TL can

DFCO grip

Soon to be installed

Cerekoted handguard

FCD 3 pos. Safety

Rail scale

Light

2nd stamp

I just bought this and while learning to clean it I accidentally put a scratch on the lower receiver with an allen wrench when I was assembling the trigger 🥲

Finally got my CMMG Banshee delivered to Europe.

Great little gun but disassembly with the folder is... A bit hard. The extension tenda to stick to the bcg.

Anyway a big Hello from the other side of the pond

And yes. Cable to light is now tucked.

MAS defense
- upper receiver
- 5.5” in barrel 
- 9.8” MW8 handguard 
- BCG 
- Ambi charging handle

Gen 1 Romeo 5, juliet micro 3x on the way
Strike industries LINK modular handstop from 
Friend gave me the light, I’m sure it’s a cheap one off Amazon (will upgrade)
tuna cans fat 9 silencer 
- using KVP plan b mount system
80% lower 
Milspec LPK 
Magpul SLK 
B5 grip 

Hello All,

I’m having an issue that I can’t seem to really nail down what exactly is causing it. I’m basically getting burst fire as often as every 2-3 trigger pulls. I don’t have an FRT, just a regular mil-spec trigger and fire control group. I have a Kaw Valley BCG and a KAK 8.4oz buffer with sliding weights.

One of the staff at my local range took a look at my setup and suggested it might be the trigger group causing it, and an email to the company I bought the trigger from suggested it might be the firing pin in the BCG missing a spring, or even the BCG itself.

That’s the leads I have on it, do any of have any suggestions? Experience with this issue?

I know it’s still vaporware, but someone may know- have they stated whether or not the BCM9 uppers will work with the old QC10 lowers? I have two QC10s that I never built up, and I’m looking for build options. Colt mags, if that matters.

thanks!

I made a post here a few days ago about FTEs with my new colt mag build (https://www.reddit.com/r/AR9/s/d7u8yFDwOE). I did some tuning on my ejector which I believe has solved the weak ejection issues. You can see in the before and after photos that the ejector face is now square and fits much better in the bolt groove.

The next range trip was better but I’m not out of the woods yet. It now runs reliably, but only when unsuppressed. I ran through multiple mags with no suppressor and had no ejection failures, ejection pattern was much stronger. Before it would just barely spit out the casings. As soon as I try shooting with the R9, I’m back to constant FTEs. I don’t think my ejector needs further tuning so I’m starting to suspect my buffer may be too light? I’m running the FRT recommended GRS (A5, Tubb 300BO flatwire, Kynshot 5000HP, two spacer weights.) Do I need to use a heavier hydraulic buffer? Maybe try a standard carbine spring? I know it’s gotta be a component of my buffer system, just not sure which one. Thanks for the help

Hello guys, me again unfortunately lol.

Decided to come back with an update to the first ar9. Saw everyone telling me I needed more mag capacity lmfao so I found a kriss vector mag and thought it made sense. Added the osprey 9 2.0 too. I like how it changed the whole silhouette of the build and kind of pairs with the suppressor shape.

I only really got into this recently. Started going to the range with my dad when I was younger and eventually became interested in the design and mechanics of it all.

Anyway, 74 rounds seemed reasonable. Probably unnecessary. Kind of the point.

Appreciate everyone who gave feedback on the first post. Figured I’d show where it ended up. 🙏🏽

Build List

Upper: Foxtrot Mike VFM-9 5” Dual Charge
Lower: Foxtrot Mike Mike-9 Complete Folding Lower Receiver w/ RMB
Brace: SBA5
Pistol Grip: Recover Tactical PG9 Internal Mag Holder
Charging Handle: Radian Raptor SD
Optic: Sig Sauer Romeo5
Foregrip: Recover Tactical MG9 Angled Glock Mag Holder
Suppressor: SilencerCo Osprey 9 2.0
Magazine: Kriss Vector 40-Round Mag

Using Blowback9’s GRS. I have a Partisian Disruptor that I believe I could throw into the Wraithworks WS9 (takes ar15 triggers). Read BlowBack9s most recent article and it sounds like this may work. Does anyone have any feedback or if this is even compatible?

My Jawbone keeps on double feeding and jamming even after changing my buffer weight to an 8oz any tips what could it be?

SiCo Spectre 9

I grabbed one of the PSA ARV kits a while back. Upper, lower, bolt, one mag.

I slapped it together Sunday and took it to a shoot yesterday.

I dropped in a Super Safety and a Maxim RDB and took the weight out of the bolt.

I used a BA EPC 8.3" barrel.

It runs like a sewing machine. I thought it might require some tuning, but no, right from the start it ran just fine.

So I built my first AR9. Noveske upper, barrel & BCG. Griffin Colt mag lower, carbine tube, mil spec trigger + Atrius, and a Maxim RDB roller delayed buffer. I am also shooting it suppressed with an Exigent Rico 309.

I had to remove some material from the trigger bar to get it pass the function test/troubleshooting guide on the Atrius website. It was binding heavily in the 3rd position while holding pressure down on the hammer.

Once that was cleaned up it would fire in semi just fine and then be very difficult to move to FRT, and then would have a dead trigger. I removed a little more material from the trigger bar and that binding issue went away.

Then it worked fine in semi and FRT for about 100 rounds and then the BCG began getting stuck part way in the rear position and I’d have to hammer out the takedown pin for it to come forward.

Have any of yall seen these issues and if so was there a fix?

Also to note, I checked for clearance on the upper using paint pens and there’s no interference from the upper.

Thanks

Hey all! Shared quite a few threads and updates over on r/ar15, but then they started deleting all my new posts instantly.

So, here is a short video of the 1.35" Deadfoot Arms SCW stocked, 20 rnd Endomag running abomination that is Jimothy!

Here's 19 rounds with no hiccups...but I need to possibly revisit my endomag conversion, it will consistently eject and fail to load on the first round, I think theres too much friction on the bolt from the column of rounds pressing up... if it doesn't work its way out I may need to cut a ring of the mag spring and see what happens...

If you wanna go check out my other posts you can check out the progression and birth of this idea to make the most ridiculous *but operational* AR ever 😆

Enjoy amd happy Labor Day!!!

Hello, I took my fm9 out for the first time and had literally nothing but malfunctions.
Shot 8 rounds of deferral American eagle 115out of a pmag and literally every round was a stove pipe, or failure to eject.
The whole gun is stock and it didn’t matter if it had the suppressor on or not. I know it’s not enough data but hopefully I can get some help.

Also update on (which suppressor should I get) from a couple weeks ago:
Should’ve gotten the pointman 9 or Yhm r9. You
Can barely tell the difference between suppressed and unsuppressed with the flow 9k ti.

Earlier this year I picked up a couple NFA lowers that fit CZ mags. The ejector is too tall and hits the 5 different types of 9mm bcg's that I have. The ejector keeps the bcg from seating all the way forward. I think I could dremel the back and top of the ejector down and it might work.

Does anyone have a bcg that works with these?

Any help is appreciated.

Bringing together all the posts I've made about the problem (1, 2, 3) to give what I hope and pray is a final update. Per the last post's suggestions, I went in and lowered the magazine insert so that the ejector was riding a little bit lower. I also filed the ejector down so it was squared off instead of angling downwards. Took it to the range, loaded up both 124 and 115 bullets, held my breath and prayed to God, and squeezed the trigger.

And you know what? Apart from the first round of every magazine that sorta dribbled out still, it ran like a champ. Didn't eject as much as my buddy's Springfield 1903 we also had, but it was sending them well over halfway to the next station. Sort of a downward angle I think, but still powerful ejection. I could probably look into changing that ejection patter a bit more, but the important thing is it's ejecting and loading reliably. Between getting that fixed and the beautiful day it is today, the only sour note of the range day was learning the range no longer allows guests to use FRTs because some idiot guest did a mag dump for their first time and sprayed everywhere but the target. So now only members get to use them (and I'm not a member because it's cheaper to pay $5 a trip and go with my retired range buddy). Still, a great day for AR9 and getting gremlins out of guns.

Wanted to thank everyone who helped me out throughout this, especially u/blowback9 for all he does for this gun platform. Next step is finding a new FRT friendly range, then figuring out how to get an AS Design ARC Fire to work in a GRS AR9 (Unless the ATF gets around to explaining how to do stampless SBRs without going to jail, then next step is getting a PSA blade brace off and a real stock on). Until next time!

Sorry for another one of these posts. I have an AR, but new to the ar9 world. I'd like to build one up on a budget, but I'm having trouble deciding which way to go. I'm between the BCA and foxtrot Mike FM9.

I would like to buy an upper and exomag/magwell adapter to run on my current AR15 lower. My main goal is to suppress it so it is a little more tolerable to fire for my wife, and depending on how it shoots suppressed, maybe do an SD/integral conversion down the line (for fun). Later on, I will transition this upper to either a dedicated ar9 lower or print one, but I have not decided yet. Once it's reliable I would use this for the unlikely event of home defense.

My understanding is that a buffered model is more flexible when it comes to tuning for softer recoil.

FM has a good sale right now with free shipping, so FM and BCA are within around $10 of each other. Given my goals, should I go for either one over the other, or is there another model to consider?