NFA newbie- dedicated suppressed 11.5" build questions

[Lawnchair 04]

Thanks ig thats what I was looking for.

[markm]

I've been monkeying with a NIGHTMARE Sabre Defence 11.5 for the last month. I just can't let go of this Piece of shit challenge.

Anyway I've tried 4 different gas port settings and found this...

.063 is pretty nice for unsuppressed shooting.

.055 is too small for unsuppressed shooting and won't even run reliably with XM193's ridiculous hotness.

.060 won't lock back unsuppressed even with 5.56 ammo... but Runs like a MOFO with a Suppresser with both .223 and 5.56 ammo, and spits out brass like a rifle.

[Magic_Salad0892]

A 16.1'' DD Car gas barrel has an .058'' port.

Get one. Have it cut down. That's a dedicated gun.

LMT Enhanced Carrier is almost a necessity on a suppressor host. Because they'll be undergassed by design.

I'd personally prefer a Colt 16.1'' SOCOM profile barrel with an .062'' port + A5 (5.1 oz.) buffer. That'll give you lock back with NATO ammo, but not with .223 in my experience. Unsuppressed.

11.5'' host + KAC QDSS-NT4 suppressor.

Mine is semi dedicated. I wanted it to run properly with a suppressor, but I still wanted it to cycle with NATO ammo.

My original guns were on cut down KAC uppers, and I had .056'' ports on 11.1'' guns. Originally used H2 buffers, and Sprinco blue springs. They'd cycle without the can, but wouldn't lock back. The A5 system changed that. They'd lock back, because there seemed to be enough time for the bolt lock to engage.

Note that I never ran the suppressor hosts without the LMT Enhanced carrier because they wouldn't cycle without it. (I had to make sure, because Grant said they wouldn't in one of his old threads, but I wanted to see if it was repeatable. It was.)

Ammo used for the vast majority of my testing was M855, Federal Gold Medal Match, Mk. 262 clone, M193, Hornady 75 gr. TAP.

[Magic_Salad0892]

The wrong port is the root of many AR problems.

Now Mark knows why I'm obsessed with port sizes.

[markm]

Now Mark knows why I'm obsessed with port sizes.

I sure do... my little Lifesuck challenge to fix this Sabre Defence has taught me a lot about the subject of gas port size.

[elnino31]

A 16.1'' DD Car gas barrel has an .058'' port.

Get one. Have it cut down. That's a dedicated gun.

LMT Enhanced Carrier is almost a necessity on a suppressor host. Because they'll be undergassed by design.

I'd personally prefer a Colt 16.1'' SOCOM profile barrel with an .062'' port + A5 (5.1 oz.) buffer. That'll give you lock back with NATO ammo, but not with .223 in my experience. Unsuppressed.

Mine is semi dedicated. I wanted it to run properly with a suppressor, but I still wanted it to cycle with NATO ammo.
.

I bought a 12.5" DD barrel and had an inch taken off. Steve at Adco measured it, but I can't remember what the port size is. Runs great suppressed, but will only cycle NATO rounds without the can. It will not cycle any 223 ammo that I've tried without.

Using a G5 with a H2 buffer.

[fixit69]

Magicsalad, do you know the gas port size of a BCM 11.5" SS barrel? I'm running an A5 and an AAC 7.62 on it's locking back with wolf steel case, XM193, etc...

Just want to know for the future, as I'm loving this barrel length.

[Clint]

.060 won't lock back unsuppressed even with 5.56 ammo... but Runs like a MOFO with a Suppresser with both .223 and 5.56 ammo, and spits out brass like a rifle.

Awesome!

I was wondering if you had done more testing over the holiday.

Is this the 14.5" or the 11.5"?

[markm]

11.5 as per the original thread title.

.060 suppressed runs silly good.

I'm going to stick with that for at least a few weeks worth of shootin.

[Clint]

11.5 as per the original thread title.

.060 suppressed runs silly good.

I'm going to stick with that for at least a few weeks worth of shootin.

Got it.

You should try and make a .060 suppressed companion video to the .070 un-suppressed one.