Knights Armament SR-25 show us your setup / discussion thread

[RHINOWSO]

You win the Internet today.

Indeed.

[Benito]

Does anyone use an adjustable gas block on SR-25s/15s?
I've never seen one. Just curious, as I see suppressed KAC guns a lot on here.
Even with properly sized gas ports, adding a can is going to significantly speed up the carrier.
Are there even any aftermarket adjustable gas blocks that would work with the KAC Mod 2 guns? I know they have a proprietary gas block of some sort.

[MegademiC]

I completely forgot to actually say what this thing is and what it does.



This is my 14.5" SR-25 E2 "ACC" (the standard ACC has a 16" barrel).
It has a MAMS under that 7.62 QDC/CQB suppressor.
The M-LOK URX4 handguard is 13" long (standard is 15").
The optic is a Leupold Mk6 1-6x with TMR-D reticle in a raised (1.93") and extended KAC 34mm mount.
The laser is indeed a BE Meyers MAWL-DA.
It is zeroed at 100 meters with 130gr SOST.
The KAC offset BUIS are zeroed at 50 meters.
Hog Saddle SS Loophole sling, with a Wiebad Lightweight rear bag (was attached forward at the time this picture was taken for barricade padding).
A KAC bipod slides onto the bottom rail section when needed.
KAC 20-round magazines with Magpul Magpuls (oriented to protect base of magazine and prevent floorplate loss) and Magpul 25-rounders.
Magpul MIAD 1.1 and STR with 0.70 pad round out the furniture.

It fills a GP role with a max effective range expectation of 500 meters on a point target with terminally effective ammunition during both daylight and complete darkness (with the addition of a UNS-A3 clip-on inline night vision device). While capable of respectable precision with match ammo, the reality is that the ammunition types to be used are not precision oriented, and therefore priority went to reliability, comfort, and handling.
It does exactly what I want it to do.

That is awesome. Thanks for the details/brief explanation.

I'm also interested in the 14.5"vs 16" question. Sounds like it just depends on purpose and expectations? How's the blast( any noticable difference from 16"?).

[Tspeis]

Jack,
Interesting and very unique setup.
How do you find that the 14.5" compares to the 16" in terms of blast/flash (without the can), noise (with the can) and your overall thoughts on pros/cons of a 14.5" .308.
I was batting around the idea of a 14.5" .308 a few years ago, but was advised against it repeatedly by very knowledgable and experienced guys, who recommended 16".

Thanks

I'm not speaking for Jack, but I found it appropriate to reply in the interest of sharing info on the subject. The two big reasons 308 rifles under 16" are not recommended by credible folks (FBI BRF, Dr. Roberts, etc...) are:

1 - No adequately reliable platforms under 16" were tested
2 - No purpose built ammunition that meets FBI protocol from guns under 16" existed

I spoke to the SSA at the FBI BRF about this and was advised they actually recommend 14" barrel lengths with 1:8" twist for all CONUS LE bolt gun use. When I asked about gas guns, they recommended 16" with 1:8" twist because they hadn't tested any under 16" that exhibited acceptable reliability. Muzzle blast / flash was another reason. In all fairness, he was up front about the fact that there are a lot of short guns out there that they haven't tested.

When people talk about the piss poor terminal ballistics of 308 guns under 16", they're usually referring to loads that were developed around 24" SAAMI test barrels, not SBR's. Using such ammunition in short guns naturally comes with an associated increase in muzzle signature. However, both terminal performance and muzzle signature can be mitigated through using a load optimized for barrels under 16". Some are already out there and some are still in development. As better loads become available, shorter guns will become a more viable option. Kinda funny how only a decade or so ago everyone talked about how 16" guns were way too short and not recommended. Same thing with fast twist rates.

I too am interested to hear Jack's thoughts on any first hand comparisons between the 14.5" and 16" ACC.


Tspeis

[Failure2Stop]

Any chance you're going to be at the USASOC competition next week, and bringing this rifle so JoshNC and I can to try it at the vendor demo shoot?

I'll be there, and a version of this rifle will be with me.

Jack,
Interesting and very unique setup.
How do you find that the 14.5" compares to the 16" in terms of blast/flash (without the can), noise (with the can) and your overall thoughts on pros/cons of a 14.5" .308.
I was batting around the idea of a 14.5" .308 a few years ago, but was advised against it repeatedly by very knowledgable and experienced guys, who recommended 16".

Thanks

I shoot that gun with a brake (MAMS), so it's about the same between the 14.5 and 16.
With suppressor, overall level is about the same. I have no issue with light shooting with no hearing protection with the setup, though it is above "hearing safe".

I like the 14.5 so long as general approaches to application are followed:
1. Even with 175gr SMKs, stay inside 600 meters
2. Ammo that drops live targets the best tend to not be terribly precise. I'm partial to those in the 130-155gr in general, but I do want to see what's up with that 168gr TSX (NOT TTSX).
3. The optics that best complement the setup are in the 1-6x/1-8x range, which biases the user more toward mid-range anyway.

One issue with 14.5 .308 in the past was function. Either the gun would run ok unsuppressed, run ok suppressed, or not really run. Lots has changed since then, with regard to both design and ammunition, the two most critical aspects of less than optimal performance.

Dudes in this thread probably don't need the observation, but don't expect .308 to be 5.56. There is a price to be paid for that power, from bare system weight and bulk to blast and reticle lift off target. I do think that there is a things as "too light" when it comes to a semi-auto .308 from a performance standpoint, but being careful about ammo can manage that.

Does anyone use an adjustable gas block on SR-25s/15s?
I've never seen one. Just curious, as I see suppressed KAC guns a lot on here.
Even with properly sized gas ports, adding a can is going to significantly speed up the carrier.
Are there even any aftermarket adjustable gas blocks that would work with the KAC Mod 2 guns? I know they have a proprietary gas block of some sort.

KAC designs and builds the guns to run suppressed and unsuppressed with no need for parts alteration or selection.
The E2 gas system, port position, and port size were all specifically balanced to preclude the need for adjustable gas blocks, just as the legacy and "Mod 1" type systems were.

[Benito]

I'm not speaking for Jack, but I found it appropriate to reply in the interest of sharing info on the subject. The two big reasons 308 rifles under 16" are not recommended by credible folks (FBI BRF, Dr. Roberts, etc...) are:

1 - No adequately reliable platforms under 16" were tested
2 - No purpose built ammunition that meets FBI protocol from guns under 16" existed

I spoke to the SSA at the FBI BRF about this and was advised they actually recommend 14" barrel lengths with 1:8" twist for all CONUS LE bolt gun use. When I asked about gas guns, they recommended 16" with 1:8" twist because they hadn't tested any under 16" that exhibited acceptable reliability. Muzzle blast / flash was another reason. In all fairness, he was up front about the fact that there are a lot of short guns out there that they haven't tested.

When people talk about the piss poor terminal ballistics of 308 guns under 16", they're usually referring to loads that were developed around 24" SAAMI test barrels, not SBR's. Using such ammunition in short guns naturally comes with an associated increase in muzzle signature. However, both terminal performance and muzzle signature can be mitigated through using a load optimized for barrels under 16". Some are already out there and some are still in development. As better loads become available, shorter guns will become a more viable option. Kinda funny how only a decade or so ago everyone talked about how 16" guns were way too short and not recommended. Same thing with fast twist rates.

I too am interested to hear Jack's thoughts on any first hand comparisons between the 14.5" and 16" ACC.


Tspeis

I'll be there, and a version of this rifle will be with me.



I shoot that gun with a brake (MAMS), so it's about the same between the 14.5 and 16.
With suppressor, overall level is about the same. I have no issue with light shooting with no hearing protection with the setup, though it is above "hearing safe".

I like the 14.5 so long as general approaches to application are followed:
1. Even with 175gr SMKs, stay inside 600 meters
2. Ammo that drops live targets the best tend to not be terribly precise. I'm partial to those in the 130-155gr in general, but I do want to see what's up with that 168gr TSX (NOT TTSX).
3. The optics that best complement the setup are in the 1-6x/1-8x range, which biases the user more toward mid-range anyway.

One issue with 14.5 .308 in the past was function. Either the gun would run ok unsuppressed, run ok suppressed, or not really run. Lots has changed since then, with regard to both design and ammunition, the two most critical aspects of less than optimal performance.

Dudes in this thread probably don't need the observation, but don't expect .308 to be 5.56. There is a price to be paid for that power, from bare system weight and bulk to blast and reticle lift off target. I do think that there is a things as "too light" when it comes to a semi-auto .308 from a performance standpoint, but being careful about ammo can manage that.



KAC designs and builds the guns to run suppressed and unsuppressed with no need for parts alteration or selection.
The E2 gas system, port position, and port size were all specifically balanced to preclude the need for adjustable gas blocks, just as the legacy and "Mod 1" type systems were.

Great info, thanks gentlemen.

[RHINOWSO]

While not specifically a KAC observation, I have a SCAR 17 that has a 13" barrel and it has operated fine with that barrel length. Ammunition used and intent of the rifle mirrors Mr Leuba's - I use 130gr SOST primarily but for training often use M80 and clones thereof in the 145-149gr weight. But I don't find recoil or blast an issue at all and I terminal ballistics are more than adequate out to my intended use (0-400m). Suppressed I get 2710FPS (10 shot average). with the MK319 / 130gr. I'm more of a mag-whore, so I have a 2.5-10x24 NF with offset RDS - but I have been considering going to a 1-6/1-8 solution.

I'd love an SR-25 but funds are lacking, as I don't do things halfassed to it'd be $4K for the rifle and anther $3-4K to get it outfitted and up to speed.

[CRAMBONE]

I completely forgot to actually say what this thing is and what it does.



This is my 14.5" SR-25 E2 "ACC" (the standard ACC has a 16" barrel).
It has a MAMS under that 7.62 QDC/CQB suppressor.
The M-LOK URX4 handguard is 13" long (standard is 15").
The optic is a Leupold Mk6 1-6x with TMR-D reticle in a raised (1.93") and extended KAC 34mm mount.
The laser is indeed a BE Meyers MAWL-DA.
It is zeroed at 100 meters with 130gr SOST.
The KAC offset BUIS are zeroed at 50 meters.
Hog Saddle SS Loophole sling, with a Wiebad Lightweight rear bag (was attached forward at the time this picture was taken for barricade padding).
A KAC bipod slides onto the bottom rail section when needed.
KAC 20-round magazines with Magpul Magpuls (oriented to protect base of magazine and prevent floorplate loss) and Magpul 25-rounders.
Magpul MIAD 1.1 and STR with 0.70 pad round out the furniture.

It fills a GP role with a max effective range expectation of 500 meters on a point target with terminally effective ammunition during both daylight and complete darkness (with the addition of a UNS-A3 clip-on inline night vision device). While capable of respectable precision with match ammo, the reality is that the ammunition types to be used are not precision oriented, and therefore priority went to reliability, comfort, and handling.
It does exactly what I want it to do.

Can I have that? You know if I ask nicely.

[RobertTheTexan]

Thanks for the kind words on the picture, I'm working to limit my potato pics to a minimum.

The sling is the SS Loophole by Hog Saddle.
http://stores.hogsaddle.com/ss-loophole-sling-1/ -
Thinking about picking up one of the "Enhanced" versions shortly.
http://stores.hogsaddle.com/enhanced-ss-loophole-sling/

I like it as it allows a user to clip the sling into a belt for significantly increased stability off barricades and tripods.

Jack - thanks for the links and the info. I just picked up the Enhanced SS a few minutes ago. Did I beat you to the punch? That sling looks to be a really good fit for my latest SBR build with my URX 4 and my KAC lower. I like the functionality described and I believe it will work well with how I like to shoot and also the direction I'm going training-wise, with building up some barricades at my little range I shoot/train at.

I'm still debating the SS LoopHole sling. I want to pick it up for my LR-308 build and I can definitely see the weapon stabilization it brings to the table. I clicked through all the photos. Impressive and definitely outside the box. I like it, but I am going to give the Enhanced SS a go first and take it from there. Funny I was at HOG Saddle a few weeks ago looking at their pig saddle, and totally missed the slings - so thank you Jack for the links and info. Sling is on its way. OD green w/Coyote hardware.

[Boba Fett v2]

While not specifically a KAC observation, I have a SCAR 17 that has a 13" barrel and it has operated fine with that barrel length. Ammunition used and intent of the rifle mirrors Mr Leuba's - I use 130gr SOST primarily but for training often use M80 and clones thereof in the 145-149gr weight. But I don't find recoil or blast an issue at all and I terminal ballistics are more than adequate out to my intended use (0-400m). Suppressed I get 2710FPS (10 shot average). with the MK319 / 130gr. I'm more of a mag-whore, so I have a 2.5-10x24 NF with offset RDS - but I have been considering going to a 1-6/1-8 solution.

I'd love an SR-25 but funds are lacking, as I don't do things halfassed to it'd be $4K for the rifle and anther $3-4K to get it outfitted and up to speed.

Pretty much in the same boat, but not giving up hope. The new home purchase last year has shifted my priorities significantly. I predict I'll be in a much better position to pick up an SR25 next year once we've got everything we want done to the home squared away. I'd like to run it as a dedicated battle rifle, but I feel I already have enough in my private arsenal as-is to handle pretty much any contingency.