Hop out out a video  on these and it seems positive. I was skeptical it would accelerate fouling in the mags/trigger group but he put out a second video  testing this and it seems to not foul anymore than standard suppressed shooting (apparently the majority of gas and fouling enters the upper/lower receiver back through the barrel vs the smaller volume of gas needed to unlock bolt via the gas tube).

The purported benefit is it reduces port noise and can be a part of tuned system to make the gun even quieter to the shooters right ear.

 I'm skeptical but it's interesting. I figured yall could help ascertain if this had merit or is a bad idea.

https://kakindustry.com/k-spec-enhanced-ar15-bcg-5-56-300-blackout-dual-ejector-down-vent-sand-cuts-chrome-lined-phosphate/

No holes in the side

Attached File

FWIW my suppressed guns have adjustable gas blocks, and charging handle is sealed with RTV and moleskin. So I get no gas to face with Turbo K and Turbo K RB - and given it's not overgassed I assume it helps in the port noise department as well.

But if I can knock a few more DB off on my side of the rifle, why not?

Moleskin hack is patent pending by me  Older pic, I've since switch to black RTV even though the red was holding up fine

Attached File

It works but it depends on a lot of factors. I tried about 10 variations before I figured out that the thing that helps the most was an adjustable gas block and a gas buster type charging handle.

Their description says “Testing has shown that venting the gasses through the magazine well has no negative impact on the feeding or function of the magazine nor ammunition” but I’d be curious to see how much additional fouling winds up going down the mag, building up inside of it/on the spring, additional brass fouling etc

Honestly,  even if it does,  who uses the same magazine consistently for the (likely) thousands of rounds to find an issue?

I'd be more worried about the FCG but not sure it takes a direct hit like the mag. I was surprised though - the second video, while not exhaustive, didn't show a material difference. I don't think the round counts were super high though.

I just got done testing mine without cleaning for approx 500 rounds.
Function was 100% without lube the whole time.
I did notice the fire control group got a little dirty but not so much that it would deter me from purchasing another.
Couple of q-tips cleaned it right up.
I ended up getting the chrome bcg and a dual ejector bolt that passed head spacing on my barrel.
That dual ejector bolt flings brass about 8-10 ft, it's quite stout.
The mags were no dirtier than normal shooting suppressed.
Overall happy with it.
I couldn't comment on the port pop noise reduction because I had ears on throughout the testing.
Testing was done over about a month long period.
I would recommend getting one because it does reduce gas to the face.

They did post the following testing for comparison:

https://www.dropbox.com/scl/fi/bnnmal1s0d4jfshpd3rkr/K-SPEC-VS-MILSPEC-SOUND-TEST-K-SPEC-WILL-MAKE-YOUR-SUPPRESSED-AR15-QUEITER.png?rlkey=b36gf8brbwly3128g7x2rpf3e&e=1&dl=0

Obviously, I don't know what testing methodology was used, but it seems interesting.

All I know is I have a 20 round pmag cause two jams yesterday at a match. The mag was slow to feed the round, I just think too much friction in the mag. The mag has a few hundred rounds thru it on the ar that is suppressed. The mag has gotten gritty and I can feel it when loading it. The ammo even four or five rounds down is filthy after firing 10 or so rounds thru it. Is it due to being in a suppressed gun or just never been cleaned before I dont know, but I took the mag out of rotation at the match after the second jam. It is the only time the gun has jammed.

I had a 20-rnd Pmag go bad on me. It was used exclusively for zeroing and now will reliably cause a problem after the first round is fired. I'm betting that was it.

It was 1/2 way or so thru the mag both times.

I use the same 6-8 mags for range use, and if they’re all taking turns it would definitely add up

I wonder how the ejection port dBs would compare with these vs the LMT Enhanced or Surefire Optimized BCGs with a delayed cam path?

+1...
I don't know if you've seen my page here: https://c3junkie.com/?page_id=1403
but I got almost the same results using an LWRC integral carrier vs the Surefire OBC carrier.  There are some posts out there basically saying the Surefire delayed path wasn't done 'right'.  I use it since it does have the increased stroke (which I get with the LWRC integral) but also has the modified gas key so you don't have to mod the charging handle.
BTW, also have an LMT Enhanced carrier and did some very limited testing with it but didn't see as big of a reduction in full auto vs the LWRC integral and the Surefire OBC so I didn't continue testing it.

I don't get any gas to the face with my build discussed above.  This is all accomplished mainly by using a large volume gas tube to increase the dwell time vs dumping the gas somewhere else.
By increasing the dwell time, you give gas more time to go out the bore instead of back into the action or your face.

I haven't really followed Hop and just recently started watching some of his videos which seem to be well thought out but this last one, he says that AR buffer springs are snakeoil which I strongly disagree with.

Back when I had MicroMOA, I strictly sold Sprinco springs and thought most springs were basically the same but I have since changed my mind since around 2017 tinkering with the CMMG RDB and have since switched everything (including 556) to flat springs.  I have empirical data to back it up as well.  
Here is one of my pages discussing it: https://c3junkie.com/?page_id=977
Flat springs are heavily used in handguns for a long time as well (like Glocks had them I think day 1).  

Can someone point me to a video/link where he has tested flat springs like I did or measure spring rates to back up his statements or is he just parroting what most people say about springs?  (which again I used to think similarly)
It is proven that flat springs have a more constant force which results in a smoother impulse.  Maybe you don't feel it and think it is a waste of money but empirical data like Tubb's video with the load sensor proves the difference.  Some have posted some of his numbers were off and did their own testing and that may be the case but I don't think there is an argument saying it doesn't have a more linear rate.  

The main difference between SpringCo and generic flat springs is SprinCo offers different spring rates. I have springs from Tubbs as well as KAK and they are not the same rates. I would need a spring tester to tell you how the two brand springs compared in overate rate and percentage difference. If a flat spring manufacturer offered different spring rates the way SpringCo does I would consider changing. As it stands, the flat springs are either the correct rate or they aren't.

I haven't tested all the flat springs out there....I just know the same company that makes them for Tubb also makes them for Wilson Combat.  I have the most experience with the 3 Tubb offerings and use them on almost all the M16 calibers I run.  The only time I go to a round spring is when I need a 'jerky' force.   Like my AK mag setups using unmodified AK mags and drums that have rough feed lips or the belt fed Shrike that needs more force to strip rounds from the belt.

For the both of you: were these straight 20s or the new gen 3 curve 20?

It was a curved gen 3 made and purchased about 5 years ago.

Regarding pre-Gen3 PMAG 20's, they don't (at least mine didn't) have any kind of rear anti tilt arm on the follower, and therefore mine suffered from follower tilt leading to sometimes simply not feeding the next round.
I divested myself of those and now stick with the Gen 3 only with 20's.
They aren't supposed to feel gritty.
Mags need to be clean to work right.  If you let a bunch of dirt get in there, you will have problems in my experience.  Clean the mags.  They need it a lot more than the gun does.

As to the BCG in the OP, I think I'd try just about anything to reduce gas before that, at least until they are very well proven... it just seems a little too off the wall to me, but hopefully they work out for the early adopters.