u/Connect-Stress4215

I’ve had this build finished for less than 24 hours, and it’s already one of my favorite pieces to shoot. I’ll gloss over receivers and handguards for the sake of keeping this post at least somewhat brief.

Noteworthy parts list:

-JRC 8.5” buffer tube.

-Kynshot RB5015HD buffer (6oz).

-Kynshot spacer weigh x2 (5oz).

-Tubbs standard carbine flatwire spring.

-BKF 9mm bolt.

-KAK tungsten heavy carrier weight.

-Novox X-SD barrel and adapter kit.

-ASD ARC fire v1.5

-Bore Buddy ARC fire timing shim

Build specs:

-OAL collapsed = 27 15/16”

-Weight w/o optic = 7lb 4.5oz

-Cyclic rate = 624rpm

-Suppressor length from rear of handguard = 11 11/16”

-Barrel length from rear of handguard = 4 3/4”

-muzzle velocity 115gr Luger/124gr NATO = TBD/TBD (will update in comments after range trip tomorrow)

Issues and Troubleshooting:

-ARC fire trigger regular semi auto in both fire and ARC position = requires Bore Buddy timing advance shim for ARC fire.

-ARC fire trigger binding with timing advance shim installed = remove shim and incrementally remove material from both sides with 600 grit sandpaper, using a circular motion, until trigger functions smoothly.

-KAK tungsten heavy carrier weight protruding from rear of bolt = use 180 grit sandpaper to remove roughly 1/16” from rear of weight, finish with 600 grit if desired.

If anyone has questions feel free to ask, I’ll do my best to answer.

I’ve had this build finished for less than 24 hours, and it’s already one of my favorite pieces to shoot. I’ll gloss over receivers and handguards for the sake of keeping this post at least somewhat brief.

Noteworthy parts list:

-JRC 8.5” buffer tube. -Kynshot RB5015HD buffer (6oz). -Kynshot spacer weigh x2 (5oz). -Tubbs standard carbine flatwire spring. -BKF 9mm bolt. -KAK tungsten heavy carrier weight. -Novox X-SD barrel and adapter kit. -ASD ARC fire v1.5 -Bore Buddy ARC fire timing shim

Build specs:

-OAL collapsed = 27 15/16” -Weight w/o optic = 7lb 4.5oz -Cyclic rate = 624rpm -Suppressor length from rear of handguard = 11 11/16” -Barrel length from rear of handguard = 4 3/4” -muzzle velocity 115gr Luger/124gr NATO = TBD/TBD (will update in comments after range trip tomorrow)

Issues and Troubleshooting:

-ARC fire trigger regular semi auto in both fire and ARC position = requires Bore Buddy timing advance shim for ARC fire.

-ARC fire trigger binding with timing advance shim installed = remove shim and incrementally remove material from both sides with 600 grit sandpaper, using a circular motion, until trigger functions smoothly.

-KAK tungsten heavy carrier weight protruding from rear of bolt = use 180 grit sandpaper to remove roughly 1/16” from rear of weight, finish with 600 grit if desired.

If anyone has questions feel free to ask, I’ll do my best to answer.

ROFgui says 628rpm, full build details, and troubleshooting steps to get ARC fire working with AR9 coming soon. Novox x-sd barrel and adapter on a rugged sub9.

I was having trouble getting my newest build to run with the ARC fire. It was going standard semi auto in both fire positions. Luckily I came across one of bb9’s recent posts where he used the borebuddy/mcmaster carr (P/N: 99040A408) ARC fire shim (.008” of advance on the cam) and that got him running. I cut a cardboard shim out of an ammo box (.015” thick) because I’m impatient and wanted to know what my fire rate looks like. As you can see, advancing the timing on the lever is definitely the fix, but I highly recommend just getting the proper .008” shim instead of relying on cardboard. The excess thickness of my cardboard shim makes the selector a little stiff going to the 3rd position.