KAC SR-16 Pressure Reduction System

[Boba Fett v2]

I was on the KAC web page looking at the features/specs of the SR-16E3. Among it's unique features is what KAC calls a Pressure Reduction System (PRS), which includes a RE that is 3/4 longer than a standard carbine length tube:

"Our Pressure Reduction system is a feature designed to increase controllability and soften the rifle’s perceived recoil. This is achieved by employing unique lengths in our gas tubes and buffer tubes. On the 16” SR25 EC and ECC models we utilize a rifle length gas system coupled with a buffer tube that is ¾” longer than the standard carbine length buffer. In some of the SR15 and SR16 models, KAC employs a similar system of lengthened components to achieve the same result.

By using this setup, the energy released when firing is spread out over more time within the weapon. This helps to relieve vertical kick in addition to a reduction in the rearward recoil force that is absorbed by a shooter’s shoulder. Various parts in the weapon system also see an increase in service life under this system. Our Pressure Reduction system serves to increase reliability and decrease fouling, especially in suppressed usage."

Now of course the VLTOR A5 system is what immediately comes to mind when I read this, albeit the KAC system makes no mention of any specific buffer weight and includes the "unique length" gas tube as part of the whole system. What I found most interesting was the fact that the gas tube portion of the PRS is incorporated into some of the SR-15E3 variants minus the extended buffer tube. And so if I'm understanding this correctly, you could maybe/possibly order the KAC RE separately (or maybe even just an A5 RE without the spring and buffer) and acheive the same desired reduced recoil effect without compromising reliability in your SR-15. Being that the SR-16 is restricted to Military/LE use, I wasn't sure if it is even possible to order the buffer tube exclusively for private use. Couldn't find much information relating to this.

[Todd.K]

7.62 rifles have a longer BCG stroke. The RE needs to be .75" longer or the buffer .75" shorter. Both are used by different manufacturers, I think the longer RE being the better way and the shorter buffer being the cheaper way.

[Boba Fett v2]

7.62 rifles have a longer BCG stroke. The RE needs to be .75" longer or the buffer .75" shorter. Both are used by different manufacturers, I think the longer RE being the better way and the shorter buffer being the cheaper way.

Right. But I'm tracking the SR-16 is chambered in 5.56 but incorporates this system, or am I missing something?

[BufordTJustice]

On the 16" SR25 ECC, it's so it can use standard carbine length buffers for the .308 as opposed to .308 shorty buffers. A longer A5 buffer would not work in that tube due to the longer stroke of the AR10-ish system, as Todd said.

As for the SR16 statements, I dunno. Jack or Kevin may want to opine on that.

EDIT: I'm going to assume that the SR16 comments are referring only to the gas system/gas port location.

[hjmpanzr]

they don't necessarily say that the extended RE is used on the SR15 or 16, although thats certainly one way to read it. See the highlighted piece. It only says that in some of those models they employ "similar" system of lengthened components which could just mean the gas tube. Some familiarity with the SR16 11.5 system and not aware of extended RE but certainly possible on the new ones.

"Our Pressure Reduction system is a feature designed to increase controllability and soften the rifle’s perceived recoil. This is achieved by employing unique lengths in our gas tubes and buffer tubes. On the 16” SR25 EC and ECC models we utilize a rifle length gas system coupled with a buffer tube that is ¾” longer than the standard carbine length buffer. In some of the SR15 and SR16 models, KAC employs a similar system of lengthened components to achieve the same result.

By using this setup, the energy released when firing is spread out over more time within the weapon. This helps to relieve vertical kick in addition to a reduction in the rearward recoil force that is absorbed by a shooter’s shoulder. Various parts in the weapon system also see an increase in service life under this system. Our Pressure Reduction system serves to increase reliability and decrease fouling, especially in suppressed usage."

[Boba Fett v2]

You may be right, and I may be reading too deep into it (or maybe not deep enough), but the PRS is specifically listed as a feature on the SR-16 while that feature is not listed for any of the SR-15 variants (IAW the KAC website) even though it's pretty much common knowledge for those who know the specs of the weapon that it has a longer-than-mid-length gas tube. This led me to assume that the SR-16 has a complete PRS system to include a lengthened RE. But if referring to only the extended gas tube you'd think that KAC would boast the PRS feature for the SR-15 line as well.

[hjmpanzr]

Could be new. I know the SR16s have other features that the 15s don't such as the medium contour dimpled barrel and different E3 bolt. Possible extended REs have worked their way in. You never know what Kevin is peddling these days. Well have to wait for him or jack to chime in.

[Boba Fett v2]

What I'm really after is information on whether or not the SR-16 does have an extended RE, and if so, is the part available as an individual component. It would imply that the KAC RE would be tuned and optimized for their 5.56 carbines, which in theory should run more reliably than the A5 I'm assuming. My understanding is that the SR-15 can be finicky with certain types of ammo with an A5 installed. Honestly, the rifle already shoots great as is, so it's not like I'm in dire need to make it shoot any smoother. Just a general RFI really. Looking forward to any input from a KAC rep. Thanks.

[MarkG]

The only feature of the pressure reduction system found on the SR15/16 is the mid-length gas tube. I think KAC's attempt was to write a single feature description that could be applied to all of the affected weapons whether all o f the features were incorporated or in this case just one.

[Boba Fett v2]

The only feature of the pressure reduction system found on the SR15/16 is the mid-length gas tube. I think KAC's attempt was to write a single feature description that could be applied to all of the affected weapons whether all o f the features were incorporated or in this case just one.

Okay. Got it. The PRS is a broad term KAC uses to define any part of the system - gas tube, RE or both - that reduces felt recoil. That answers my question then. I guess I was a little confused when I saw it listed as a spec for the SR-16 but not the SR-15, both of which have extended mid-length gas tubes. Made me think that the SR-16 also might have had an extended RE as well. Makes sense. And it also makes sense then that by adding an A5 system might make the carbine run less than optimal given specific types of ammo. Especially considering it's already perfectly tuned to be a soft shooter that can eat any type of commercially available ammo it's fed.