Just wondering if it’s ok to do this;
I’ve seen the KX3 flash hiders on the 11.5" bbl, but never on the longer barrel lengths.
Is there a reason? Just curious!
Thanks!
Abdon
The KX3s help shorter barrels get enough gas and cut down on the concussion of the muzzle blast. This isn’t usually a problem with ARs/M16s with barrels longer than 11.5" It’s a heavy muzzle device, it wouldn’t be real practical on a 14.5" or 16" or longer AR.
A lot of people don’t think they make since on a 11.5" since it makes it a little longer.
Here’s mine on my 11.5" Zombie Killer AR w/KX3.
This is my 11.5" w/A2 flash suppressor upper next to my 11.5" w/KX3 Zombie Killer AR.
gotm4 is right on. It would be a waste on a 16" gun.
I did one permanently attached on a 13.6" barrel that started out as a 1/7" Colt HBAR barrel. It works very good with the mid-length gas system, and is very comfortable to shoot.
No SBR issues either as it’s just over 16".
so would it be o.k. to use it on a 16" barrel if it runs on a mid length gas system?
Okay to use, just not necessary.
gotm4; thanks for the reply. what would be a better choice for that appilcation?
An A2, Vortex or Phantom. The KX3 on a 16" barrel will just add more gas which is doesn’t need and add unnecessary weight. A midlength is designed to make the gas system longer which makes the the rifle cycle slower, run better with lower port pressures and fixes the extraction problems like many carbine length gas systems have.
The KX3 will add more gas which will sort of negate the reason for using a midlength.
good information, makes sense. thanks much.
Yep, Rob can make sense every once in awhile.
The KX3s do take alot of that noise and throw it down range. It makes my 10.5 inch barrel sound like I am shooting my 16 inch.
Cya, and goodluck
G
The KX3 can also induce malfunctions into a weapon that is 16" in length. I have had a couple customers have problems with this config and is why the KX3 should only be used in guns that are 14.5 and shorter.
C4
What sort of malfunctions?
Abdon
It can “over gas” the system.
So you’d then need to add a heavier buffer and over strength buffer spring to counter the gas pressure – even then you may not be able to balance the increase off.
AR’s are a unique balance in the gas system with the length of the tube and its volume and the size of the gas port.
Its a similar issue of when you add a Can to a M4A1 – ROF goes up - fouling goes up - reliability and MTBF go down.
KevinB basically covered it. The malfunctions can generally look like FTF problems.
C4
I think it would suck to have 3 extra, useless ounces out there on the end of your barrel when shooting multiple targets. We already hang too much crap off most of our rifles. For a shorter rifle, it makes sense; not so on the longer rifles.
I can’t say I agree. (although on a 16" mid-length, I’d have to agree with you)
Your 11.5" barrel has the gas port at 7.75", and has a remaining 3.75" of barrel before the KX3.
My mid-length gas system has the port at 9.625" with a remaining 4.125" of barrel before the KX3.
With the lower port pressure of the mid-length, and just slightly more dwell time (.375"), the case could be made that the KX3 is more useful on my setup than yours.
IIRC the M4 has a barrel length of 14.5" because 4" of barrel past the gas port was the magic number that worked well (according to the USMC & Colt). Coincidentally a mid-length 16" barrel has this similar length of barrel past the gas port along with a longer gas system.
This causes a sufficient amount of ‘dwell’ time and lower pressures and lower heat than a carbine length gas system. It will have better reliability and less wear & tear vs. carbine gas system or carbine gas system combined with shorter amount of barrel past gas port.
Again, adding more gas to a midlength will negate the reason for using a midlength. Yes you might have less port erosion because the port further ahead but you will be back to square one, too much gas.
The Bulgarians originally designed these things for their 7.5" AKSU-74’s in 5.56x45mm and 7.62x39mm to add more “umph” for the bolt carrier.
I use one on a 14.5 precision rifle, but it is mainly to provide reliable function with a full stock and rifle buffer, and for keeping everything directed forward for shooting in the urban environment. For most folks, it makes more sense on the shorties.
In the big scheme of things, as long as it works for YOU as the individual owner/ operator, thats all that matters. It sounds like an interesting setup, and if you get a chance, I would love to see a picture.
gotm4- You need to check your measurements.
An M4 barrel has the port at 7.75", and has 6.75" of barrel past the port.
(The 16.25" barrel has 8.5" of barrel past the port)
A mid-length 16" has the port at 9.625"with 6.625" of barrel past the port.
Based on your posts, you feel the mid-length works better (“It will have better reliability and less wear & tear vs. carbine gas system or carbine gas system combined with shorter amount of barrel past gas port.”).
You also seem to feel that by my adding the KX3 I have “over gassed” the system.
How is this?
My 16.1" (total length) upper isn’t any longer than the 16" mid-length barrel that you say is optimum. Is the KX3 going to add more gas pressure than the equivalent length of barrel? I doubt it. More dwell time, perhaps, but not more pressure.
So let’s look at this.
My 16.1" KX3 upper has less gas pressure than: The 14.5" M4 barrel, the 16.26" Carbine barrel, and the 16.25" Mid-length barrel, but somehow I have “over gassed it”(?).
Really…
BTW- I chose the mid-length gas system for this rifle as I wanted to have a minimum legal length barrel (non-SBR) with the KX3, and I did not want to over gas it with the carbine length gas system. The upper has been extremely reliable, and shows no indication of being over-gassed. In fact, I had to open the gas port more than I originally expected to.