9mm AR build questions

[Bflo]

I’m planning a 9mm AR pistol build with the intention of SBRing it on a Form 1. I want to go with a 7 inch rail and have the muzzle threads start just past the end of the rail. My original plan was to go with a 7 inch ADCO barrel with ½-28 thread, but my understanding is that the barrel length is measured from the bolt face so this would result in the threads being under a 7 inch rail.

I’m not dead-set against having the barrel buried in the rail since I will be using a Guardian 9 once it gets out of NFA jail. However, I do want the option to shoot it unsuppressed, so I will need some sort of muzzle device to clear the rail. Most 9mm muzzle devices are threaded ½-36. Does anyone know of a good muzzle device that has a ½-28 thread? The Noveske KX3 is an option, but is a bit expensive and hard to find.

So bottom line, my questions are:
Does anyone know of a 9mm ½-28 thread barrel that will clear a 7 inch rail? What length will accomplish this?

Does anyone know of a 9mm muzzle device with a ½-28 thread that will help a 7 inch barrel clear a 7 inch rail and allow me to shoot it unsuppressed?

 

[DaKruiser]

I have a 8.5" barrel, sticks out about 1/2" past my 7" rail.

Have you looked for one of the fake suppressors?

 

[DaKruiser]

US Machinegun: Fake Suppressor for 9mm Pistol 1/2x28 Threads, FAKE SUPPRESSORS/FAKE SILENCERS, FS-0116

I've not bought anything from this place, I just found it with a quick google search.

 

[rvb]

I had my 9mm cut for 1/2x28 which is the std silencer pitch for 9mm pistol cans. I have a std AR A2 flash hider bored out for a 9mm. Std AR threads are 1/2x28. I imagine you could accomplish the same w. many std muzzle devices (but not all). 9mm ARs use the x36 pitch just so you don't accidently put a .223 muzzle device on and blow up the gun.

You will probably want about 1.5" longer barrel than HG, but that will vary by the length the threads are cut, attachment method of can, etc. should give you about 1/2" gap between HG and silencer (and some of that may get used up if the threads are cut slightly longer). Depends how close you want to cut it.

i have my can recessed in the HGs. I almost never use it w.o the can because 1) WHY? and 2) I don't consider it all that safe.

-rvb

 

[42769vette]

I built a 300 BLK once and "tucked the barrel" I had a 10ish inch barrel, and a 14 inch hand guard. Since I never shot the rifle un suppressed I had no concerns with he setup.

Its the one on top

 

[Bflo]

Thanks everyone for the quick and informative responses!

DaKruiser, where did you get your 8.5 inch barrel?

 

[jd4320t]

Yep fake suppressors are cheap and work well. I have on on mine. 7" rail with a 5" barrel.

 

[DaKruiser]

Thanks everyone for the quick and informative responses!

DaKruiser, where did you get your 8.5 inch barrel?

I had a 16" cut down and rethreaded, I wanted it flush too. I have a kx3 on it now, and a Guardian on the way.

 

[rvb]

I had a 16" cut down and rethreaded

Thats what I did also. Mines 5".

-rvb

 

[Bflo]

Quick follow up question, for those with a longer rail than barrel, are there issues with getting a threaded suppressor on and off?