Milled 80% receiver with Stern Defense adapter, BCA bufferless 7.5" upper, Huxwrx Flow 9k Ti

She shoots real nice and runs like a dream. Will polish the feed ramp in the coming days but she ate through Blazer brass with no issues. Only put about 50 rounds through it that day.

Is anybody running a 4.5 inch 9mm barrel from RTB Arms? Have you experienced any problems with the feed cone. I am waiting on an Angstadt Arms bcg so I haven't shot is yet but the cone seems to me not to be beveled too deeply. I will put a trigger kicker on it and I am wondering if I need to purchase a Stern barrel or if this one will handle it. I know I am putting the cart before the horse but curious if anybody has experience with this barrel.

I could have sworn it was Tubbs, but I remembered after that my dumbass sold an extra Tubbs I had on GAFS a while back and kept the “other one” and unbeknownst to me it’s not a fit for our needs with Kynshot.

Needless to say after I searched the sub and found out it’s on the no good list.

Leaving as a PSA. My Colt Build was almost complete last night 😭

Has anyone gotten a Super Safety to work in either of these? I have both and put a Sylvan folding stock on them, which required me to remove the BCG weight. Someone suggested this would also allow me to operate a Super Safety.

Has anyone successfully done this?

Planning my 1st short barrel AR pistol project and could use some advice. The goal is to build a reliable setup on a budget of 800 dollars maximum for the base gun.

My plan is to eventually run this gun suppressed and eventually install a FRT . Ammo cost is not a problem for me. I do not mind doing mods or swapping out internal parts like buffers and springs to get the timing right. The base gun just needs to fit the budget and be available to buy right now.

Here are the main features for the build:

• Short barrel: Looking for something small, around a 5 inch barrel.
• Caliber: Open to 9mm or 45 ACP options.
• Setup: The system needs to handle increased gas blowback from a suppressor. The bcg must be reliable and able to handle full auto if for a .45..
• Last round bolt hold open: This feature is a high priority for the build but not a total dealbreaker if the gun runs well.

I already looked at GForce and Bear Creek but backed away due to quality control issues, weird barrel threads, or missing features. Foxtrot Mike is great but always out of stock so please do not suggest them.

What complete setups or upper and lower combinations are available today under 800 dollars that offer a reliable foundation? What are the standard recommendations for extra heavy buffers or springs to manage gas blowback and cycle timing safely?

I am more than happy to replace parts or perform modifications to get the build running perfectly.

Thanks for any tips from anyone who has worked on a similar build!

I’ve got a bunch of spare AR parts and want to put together a 9mm PDW. The plan is to have a 4” barrel and shoot suppressed 90% of the time. Do you guys recommend just sticking with a heavy buffer? Radial delay is cool but for the cost of the bolt and barrel I might as well just put the money into an MP5 clone. Other options like the Maxim roller delay buffer seem promising but I’m not sure if it’s worth the extra cost and complexity. Any feedback would be great.

Ok from the top I’ll just list the important items,
Midwest industries 9mm mi-mb4 brake
11in ballistic advantage EPC barrel
RTB Bolt weight notched(Colt/Glock) compatible
Kak 10.5oz buffer ( tungsten weights)
KVP XP Pcc carbine spring
R&D precision Colt Mag Adapter
Arc Fire V2 ( no shim)

Just got into all this and found a stock brigade bm-9 at my local! Threw some cheap attachments on it and ran it without any malfunctions at the range, any recommendations on what I should get next👀

Stock brigade bm-9
Cheap amazon red dot
Cheap Amazon laser/light combo
Promag 30rd drum

Bought this jawbone cleaned and oiled it up and took it straight to the range and ran 150rnds of fmj through it with only a few feeding issues swapped to sig elite defense hollows and was constant double feeds and jams🫩

yall think its a magazine issue, ammo issue or just not broken in yet?

Im tryna find out a good buy to get a pcc that has drop in 3 position frts for I've been looking at the psa jakl with the as designs trip and 3 pos safety selector not tryna shill out 2k for a pcc but want it to be fun and practical aorund like 600-1000$ range for the gun itself obv

Compared to the other barrel lengths I’ve tried with my GRS setup, this one honestly gave me the most trouble, but likewise the most satisfaction when she finally ran.

The build started as an Alpha 3” barrel with a dead air wolfman, Tubb carbine spring, BKF bolt w/kak tungsten bolt weight, JRC 8.5” tube, RB5015HD, and 2 Kynshot spacer weights. It ran flawlessly in that configuration. 27.6 oz total mass

Once I changed it to the Novox X-SD barrel, it ran well for the first couple of mags outside of the ejection pattern being at my feet. That lazy ejection evolved into stovepipes with only a little carbon fouling on the bolt. Frustrating to say the least.

I tried a few troubleshooting steps. Starting with the Tubb lightweight, then I tried removing the spacer weights one at a time (moving them from the front of the buffer stack to the rear). With both spacer weights removed, at 22.5 oz total, the rifle was finally cycling reliably, but the recoil impulse was atrocious.

I finally decided to try the RB5007, starting at full system mass, in a last ditch effort to get her running. This video is the result.

So far only 75 rounds through her in this configuration, with only one stovepipe. I may have to remove 1 spacer weight, but I’ll keep testing at this weight before reducing further, I’ll also try different ammo as well, as this is some really soft shooting 124gr Luger (new republic).

All this said, if you guys have questions or tips, feel free to weigh in.

I went to the range today and shot my ar9. Which makes me confused as I already shot this gun and didn’t felt trigger slap when I shot it. When I went to the range the trigger slap was so aggressive and pain what I can do

Build List:

Foxtrot Mike ar9 lower and reciever (3Inch barrel)
EMT-9 PCC Trigger
Deadfoot arms 2.5 buffer tube, modified 9mm BCG and spring kit I’m using the black springs the heaviest set up and recommended for 9mm
Deadfoot arms brace gen 3
BG Defense 2.9 picatinny Handguard
BG Defense Handstop
KVP MACH 3 Modular Linear Comp Body

This BRT is my only AR9. And it’s a BLAST to shoot!

It’s a tricky frt host to tune - the buffer setup and ammo selection have to be just so. But there’s enough info out there to find what typically works.

A5 tube, variable pitch spring, and Kynshot 5000A5 here with HSL 115 turned subsonic by this true weapons system.

If you’ve considered a BRT complete upper… I can tell you they’re awesome!!

PSA lower, BCA 7.5" bbl upper. Kung Fu grip, Magpul ESK selector, Magpul MOE stock dremel-go-burr'd to include QD mount, Streamlight Protac RL MNT 1L-X PRO 850LM with Axon Unity button, modified Magpul handstop kit, and a KAC compensater. Not pictured: KynSHOT hydraulic buffer.

Honorable mention: friend 3D printed light cap, KCI 33 rd magazine with Wolff spring upgrade.

EDIT: the optic is a Holosun 510, Magpul MS1 sling. Stock corrected.

EDIT, EDIT: I ~DEFINITELY~ didn't put this stock on before 12:01 AM October 9th!

Currently I have a CMMG barrel threaded 1/2x36. Just getting into the suppressor world. I believe the YHM R9 states it is HUB compatible…which I’m not entirely sure I know what that means. I have found a KAW Valley Plan B taper mount brake in 1/2x36. Im not sure I understand plan B/HUB compatibility.

Would I thread the 1/2x36 KAW valley plan B onto the barrel, then the suppressor goes directly to that? I have to remove the direct thread cap? Or is there an adapter between the plan B muzzle device and the suppressor?

Saw this on their site about timing for the ISU9 and I don’t think it was there before, so figured I’d share in here

Im newish to the PCC world. I got a GFORCE JAWBONE for $450 at my local gun shot. Im just wondering what are some good upgrades im getting a vortex sparc and one mag im just wondering what are some good upgrades and its the 5 inch barrel. Build list there really isn't non There are no upgrades grades yet but the red dot and I got the only mag from when I got it.

Im newish to the PCC world. I got a GFORCE JAWBONE for $450 at my local gun shot. Im just wondering what are some good upgrades im getting a vortex sparc and one mag im just wondering what are some good upgrades and its the 5 inch barrel. Build list im going to gwt a buffer spring and and suppressor and more mags and a different brace and a different charging handle