Knights SR15 E3 Carbine MOD2 and .223 questions. ... [Archive]

TacPlinker

08-20-15, 08:50

Seriously considering the SR15 E3 Carbine MOD2 for SHTF duty. Has anyone had or heard of any cycling problems with QUALITY .223 ammo ? I always plan on using nothing but the best in 5.56 (Federal and Blackhills) but for considering the SR15 as a civilian SHTF gun one must plan for the possibility that 5.56 ammo may not always be available at the given moment in a bad situation. There's just more .223 out there.

In particular is the mid-length gas system good to go while running weaker .223 if need be. Looking at the 14.5 middy.

http://http://www.knightarmco.com/sr-15-e3-carbine-mod-2/?cate_cm=commercial&term=sr-15&features=sr-15-carbine-mod-2 (http://www.knightarmco.com/sr-15-e3-carbine-mod-2/?cate_cm=commercial&term=sr-15&features=sr-15-carbine-mod-2)

I appreciate all replies.

TP....

w3453l

08-20-15, 11:22

I really hope more people post in this thread; I'm really looking hard at the exact same gun you are talking about.

I know on "the other side" KAC reps are pretty active in posting in their industry sub forum, so I read a lot there. I remember a post about the ammo they use to test each rifle before leaving the factory from a KAC rep, I forgot who, but I'm sure he's active here as well.

I specifically remember him saying it was PMC. He didn't specify if it was the X-tac or not, but considering the nature of the thread it was posted in I'd assume it was just the .223 pressure PMC.

I'm sure someone will come in here with a more definite answer for you.

GH41

08-20-15, 12:42

There is no doubt that KAC makes a fine rifle but I wouldn't want one for my only SHTF weapon. Too many proprietary parts.

03scgt

08-20-15, 13:17

There is no doubt that KAC makes a fine rifle but I wouldn't want one for my only SHTF weapon. Too many proprietary parts.

Ever heard of anyone breaking any of those proprietary parts? I havent.Hell ballistic radio put 21k rounds through his mod 2 without any malfunctions or problems and it still shoots moa lol.You arent breaking the bolt or gas tube so the small parts you should already have on hand for any rifle are no big deal.

I have both the mod 1 and mod2.The sr15 line of rifles is handsdown the best purchase I have ever made when it comes to an AR15.My gun cycles everything from tula up to some 77gr loads.I generally feed them nothing but wolf gold/ppu/and freedom reman and I have never had an issue with either style sr15.
http://i236.photobucket.com/albums/ff141/PBALLDONKEY/Mobile%20Uploads/20150727_170558_zpsum7m2hdz.jpg (http://s236.photobucket.com/user/PBALLDONKEY/media/Mobile%20Uploads/20150727_170558_zpsum7m2hdz.jpg.html)

cop1211

08-20-15, 13:37

I have 10 KAC rifles with another one that will be delivered Monday. They will eat everything.
Get the KAC , you'll love it. I use them all on duty/SWAT.
Can you have a malfunction? Of course, no such thing as a rifle that will never have a malfunction. But if you shoot decent ammo you'll be fine.
I'll be getting a Mod2 in the next 6-8 months.

cop1211

08-20-15, 13:40

You can also order direct from KAC for LEO pricing.

GlockWRX

08-20-15, 14:27

I have an original SR15, a Mod 1, and an SBR. They are all stellar performers and I have not any malfunction that was attributable to the weapon. I shoot Federal XM193 almost exclusively. I have also put these guns on full auto lowers and run them suppressed. No problems what so ever. When I bought the original SR15 I ran it for over 3,500 rounds without cleaning, through several classes. I finally cleaned it when the black goo oozing from the upper ruined a nice Under Armor shirt I was wearing. I've also run them so dry that when I pulled the BCG out of the upper carbon powder falls out; no lube left at all. Mine have always run despite my attempts to test their limits. I also run mine with buffers one step up from stock with no ill effects.

They are great performers.

JG007

08-20-15, 16:29

Wasn't there tons of posts a couple years ago about, to the dismay of some, they started making bigger gas ports to accommodate cheap ammo? Similar to many companies

Koshinn

08-20-15, 16:42

There is no doubt that KAC makes a fine rifle but I wouldn't want one for my only SHTF weapon. Too many proprietary parts.

I don't understand this argument. If you break a bolt in a mil-spec AR, what will you do? Hope to scavenge a new bolt? Is that bolt going to be in an AR on the ground or do you expect to find a stockpile of spare bolts?

Does this mean you don't recommend any pistol besides the 1911 for SHTF because they're all proprietary?

Does this mean absolutely no other long gun besides a mil-spec AR is suitable for SHTF?

TacPlinker

08-20-15, 16:55

So as I see it the only proprietary parts to worry about in an EXTREME situation are the cam pin, bolt and firing pin. That I can store in the grip. If I ever blow through those items then I would just swap in a spare upper. I'm sold.

So are you guys talking about experience with the 16 or 14.5 middy?

TP...

Horsehide

08-20-15, 17:04

Our 16" Mod 1s have been boringly reliable. Accuracy probably better than average: hitting 1" dots at 100 yards with a x6 scope is not an issue.
We run H2 buffers, suppressed or not. A couple of spare parts sets will ease your worries if the Barbarians ever come knocking at your door if the $h!t ever hits the fan...
SBRs are nice, but it all depends what you expect to do with your carbine. Do not expect the same suppressed performance out of an 11.5" or 14.5", but I do not know it it is a concern to you.

scooter22

08-20-15, 17:18

Do you not have a spare bolt for your standard AR?

The KAC bolt may be more expensive, but the juice is worth the squeeze to many.

Failure2Stop

08-20-15, 17:20

If you have any questions about KAC, feel free to hit me up.
I'm on the Govvie side, but stay in touch with the commercial side products as well (as they all evolved from the Gov side anyway).

tom12.7

08-20-15, 17:20

Knight's makes pinnacle products related to their rifle evolutions. When another competitor gets close, Knight's ups them one, and keeps that trend up. I would tend to say that they have enough info gathered that they have succeeded so far in that respect.
Early E3 SR15s ran like a dream with 5.56 ammo, those are still amazing rifles, but they suffer some issues with other ammo with other issues. Later models ran a larger gas port, with the sacrifice of some of the smoothness for a wider range of function with other than good 556 ammo. The MOD1 versions use the same port, with other advantages. Same with the MOD2 that offers even more advantages, plus the "throwback" to the older SR25 type gas block retention, among other things. Smaller gas tweaks have been made, but not by a large margin.
My early MOD2 16" came with a 3 ounce buffered system. I would expect that they would offer the better performing H2 carbine system as a standard later on 16" guns, instead of the SBR's only, with appropriate porting in the future. Or, they could simply use a SR25 RE, with an extended length buffer with the rifle spring, that would be excellent.

cop1211

08-20-15, 17:53

Both 16,14.5, and 11.5

GH41

08-20-15, 19:51

If you have any questions about KAC, feel free to hit me up.
I'm on the Govvie side, but stay in touch with the commercial side products as well (as they all evolved from the Gov side anyway).

Just for giggles..... I want a spare BCG..... How much will it cost and how long will it take to get?? Imagine the theme song from the Jeopardy Show playing in the background.

TacPlinker

08-20-15, 20:08

Just for giggles..... I want a spare BCG..... How much will it cost and how long will it take to get?? Imagine the theme song from the Jeopardy Show playing in the background.

Good question. I would be interested in this information as well. :)

Failure2Stop

08-20-15, 20:16

I can only do mil and LE direct. Otherwise, I'd have to direct you to boltcarrier.com or operation parts.
If you have creds, email me at jleuba@knightarmco.com.

From Tapatalk:
Jack Leuba
Knight's Armament Company: Military/Govt Product Liaison
F2S Consulting: Director of Shooting Stuff

TXBK

08-20-15, 20:21

SR-15 Enhanced Round Lug Bolt Assembly (https://www.boltcarrier.com/product/sr-15-enhanced-round-lug-bolt-assembly/) at Boltcarrier.com for $212.72.
.

hotrodder636

08-20-15, 20:35

http://www.kingopticusa.com/KAC_STRIPPED_Bolt_p/kac20433.htm

Stripped bolt. Many other "proprietary" parts in stock as well.

TacPlinker

08-20-15, 20:38

SR-15 Enhanced Round Lug Bolt Assembly (https://www.boltcarrier.com/product/sr-15-enhanced-round-lug-bolt-assembly/) at Boltcarrier.com for $212.72.
.

Well alrighty then. All thats needed to cover all bases are the firing pin and cam pin to complete the extra KAC specific parts stowed in the grip.
Good find .

TP....

TXBK

08-20-15, 20:49

However, for a SHTF weapon, I would skip the pinned muzzle device and go with a 16" barrel or 11.5 SBR. But, that's just me.

MegademiC

08-20-15, 22:13

Just for giggles..... I want a spare BCG..... How much will it cost and how long will it take to get?? Imagine the theme song from the Jeopardy Show playing in the background.

What is $212 + shipping and ship in 24 hours, Alex?

TacPlinker

08-21-15, 06:29

However, for a SHTF weapon, I would skip the pinned muzzle device and go with a 16" barrel or 11.5 SBR. But, that's just me.

Living in NJ requires all barrel lengths to be pinned. So 14.5 pinned makes sense here. :(

TXBK

08-21-15, 06:34

Living in NJ requires all barrel lengths to be pinned. So 14.5 pinned makes sense here. :(

I gotcha. I can't imagine living under such conditions. ****in commies.

Failure2Stop

08-21-15, 08:15

Well alrighty then. All thats needed to cover all bases are the firing pin and cam pin to complete the extra KAC specific parts stowed in the grip.
Good find .

TP....

http://www.operationparts.com/kac-knights-armament-sr15-field-repair-kit-new-style/

https://www.boltcarrier.com/product/knights-armament-sr-15-field-repair-kit/

http://shop.knightarmco.com/ProductDetails.aspx?ProductID=KM23339-1

hk_shootr

08-21-15, 13:33

My Mod 2 has right at 4200 round fired. Has not even given the slightest hint of a malfunction.
I have shot everything through this. To include some Tula and Classic Wolf. I prefer xm193.
Never hurts to have spare parts on hand, I have a Knights bcg available if needed.

http://i30.photobucket.com/albums/c341/faawrenchbndr/Knights/DSC03617.jpg

Wake27

08-22-15, 04:12

The more I read, the more I'm leaning toward a CQB whenever I get back to a free state. Has anyone ever put an A5 on a KAC?

Sent from my iPhone using Tapatalk

firefighter37

08-22-15, 09:10

The more I read, the more I'm leaning toward a CQB whenever I get back to a free state. Has anyone ever put an A5 on a KAC?

Sent from my iPhone using Tapatalk

I put a few of my Knights uppers on an A5 lower, with all the various buffer weights and noticed no marked improvement, so I have left the factory buffer setup on all my KAC lowers.

Koshinn

08-22-15, 12:56

The more I read, the more I'm leaning toward a CQB whenever I get back to a free state. Has anyone ever put an A5 on a KAC?

Sent from my iPhone using Tapatalk

I have an a5 with a5h2 (standard) buffer on a sr16 upper. No noticeable improvement to be honest.

tom12.7

08-22-15, 19:25

firefighter37

08-22-15, 19:30

The A5 or rifle like action system offers many positive attributes to function in basically all carbine action systems, there are a few exceptions, but the 5.56 KAC rifles are no exceptions, no matter the barrel length in SR15/SR16 systems. The A5 or rifle like action system still needs to have the correct balance between spring and mass, but there are no net negatives in function when properly balanced.

I don't think anyone meant it was worse with the A5, but in my experience with my Mod 1 LPR, 16", and SBR uppers, I noticed no appreciable difference in any of the available A5 buffer weights to justify the expense of the A5 on those guns.

tom12.7

08-22-15, 19:51

A more thorough explanation while breaking down points comparing the types of action systems into how they operate and what the results are is a side track to this thread. If interested, start a new thread instead of a tangent to this thread.
It would be difficult in most cases for a carbine action to work as well as the A5/rifle like action overall.

BufordTJustice

08-22-15, 21:12

tom12.7

08-23-15, 16:32

Yeah, pretty much so.

TacPlinker

08-23-15, 16:51

As OP I'm also interested in seeing a separate thread on the A5 in relation to the SR15 and other brands. I happen to run the A5 in standard form on a 5.56 and a 6.8 carbine actions . Although felt recoil is subjective I bought several based on data regarding slowing down carrier speed. If memory serves me correct there was a measurable difference between standard issue and the A5.

Thanks for the replies fellas.

TP....

tom12.7

08-23-15, 17:17

The A5 system can offer benefits to SR15s and others that use the conventional carbine type action systems. A properly balanced carbine action system is not on the the same level of function that the A5 action system is capable of. The increase in time for the events that occur work much better with more time from the A5 than from what is in the realm of capability in the carbine like action system.

Failure2Stop

08-23-15, 18:13

The A5 offers much more advantage to systems that are not designed as a whole.

From Tapatalk:
Jack Leuba
Knight's Armament Company: Military/Govt Product Liaison
F2S Consulting: Director of Shooting Stuff

straitR

08-23-15, 18:45

I bought a Mod 2 in January, from Ayan at Boltcarrier.com. I can't recommend the rifle or Ayan enough. I feed it whatever I happen to have, usually bulk (read: cheap) .223 or whatever my buddies have if I run out. I've owned a Sabre Defense (stolen), a Colt 6920, still have a Noveske Light Recce and a BCM LW Middie (factory upper/factory lower). The SR15 is everything I wanted it to be, and more. I live in Central FL, so KAC stuff is popular for being local, and I've never met anyone that's regretted owning one of their rifles. The biggest problem with KAC is the fact that you just want to keep buying more.

One thing to remember about the proprietary parts, is they're proprietary because they're all things that Knights has made drastic improvements to. IMO, the SR15 Mod 2 is the pinnacle of what's currently being done with the AR platform.

Also, John and the boys at Ballistic Radio seemed to enjoy theirs as well... http://ballisticradio.com/endurance-tests/kac-sr-15-mod-2/

https://farm8.staticflickr.com/7649/16360862723_17bc507265_c.jpg

tom12.7

08-24-15, 16:55

For the most part, I agree with F2S, but advantages are still there when a properly weighted and sprung A5 type of action system is used for that system.

The A5 offers much more advantage to systems that are not designed as a whole.

From Tapatalk:
Jack Leuba
Knight's Armament Company: Military/Govt Product Liaison
F2S Consulting: Director of Shooting Stuff

wilson1911

08-28-15, 10:16

I have owned and built a bunch of AR's over the last two years. I sold everything except my KAC's. I originally bought mine for the ambi controls since I shoot left handed. I do not know how to convey how good the weapon really is. If you have a friend who has one, ask him to go to the range with you one day. Seeing is believing how good they are. There is a reason so many people who purchase become converts.

I can say they are picky when it comes to ammo. They have an insatiable hunger for anything that goes bang. Kind of like the fat chick at the buffet. It will eat all yours and your friends and ask for more. This includes Tula, all Wolf ammo, Fed, IMI, Herters, and so on. The only time I have had problems with mine is when I shot about 500 rounds of herters without a cleaning. I missed 3 coyotes due to short stroking. I solved this by cleaning with a chamber brush. Metal cased ammo is fine, but keep the chamber clean.

While at the range one day with some friends I had them shoot a BCM, Noveske, and my KAC. Guess which one they all liked the best ? The gun just feels good when you shoot it.

I do not worry about the proprietary parts in the gun. Get a spare parts kit for the BCG and call it good.

I bought my first KAC 4 years ago. It was one of the best decisions on a gun purchase I have made. Out of the box gun that only needs a grip. The trigger alone makes the purchase more than worth it.

If I am at a class/range I normally let others shoot it as well. After they touch it for the first time, I always tell them to "drive it like you stole it" and have fun.

If I wanted an ultra reliable AR what would I choose - KAC
If I could only have one AR what would it be ? - KAC
If the sky is falling and the world takes a crap - KAC
If I am a left hand shooter wanting ambi controls - KAC

Feed me and clean me, then I will always take care of you.

It's not about being a fanboy of the brand. It's about being a believer in the product. I do think they charge a bit too much when everyone else's are much cheaper, but you get what you pay for.

phaseshift

03-30-16, 13:47

I fired my mod 2 14.5 yesterday with my noveske lower with A5 buffer system for the first the first time and OMG! Easily my fav AR of all time. I fired all XM193 yesterday and I had no issues except when I used Remington .223. Any tips on what to do to get it to eat cheaper ammo? I have wolf gold but haven't tried but I have xm193 and wolf gold for all my ammo.

Koshinn

03-30-16, 14:09

phaseshift

03-30-16, 14:37

use a lighter buffer.

Would I be able to just use the KAC buffer that came with my mod 2 upper? Or do I need to use a different spring and buffer tube with it?

jstalford

03-30-16, 14:46

Would I be able to just use the KAC buffer that came with my mod 2 upper? Or do I need to use a different spring and buffer tube with it?

You need a lighter A5 buffer. If you're running an A5H2 now, try an A5H1 and A5H0. You can't run standard buffers in the A5 tube.

JG007

03-30-16, 15:17

The intermediate gas + A5 buffer *seems* like a natural upgrade. I remember Joe C. (sharp guy, haven't seen him post in a while) talking about that

phaseshift

03-30-16, 16:18

You need a lighter A5 buffer. If you're running an A5H2 now, try an A5H1 and A5H0. You can't run standard buffers in the A5 tube.

If I go with the h1 or h0 will there be reliability issues with 5.56?

tom12.7

03-30-16, 17:19

Unless something new has recently happened from KAC, all of the 14.5" and 11.5" 5.56 uppers and complete rifles ship with their H2 carbine buffer. The H2 carbine action is pretty much equivalent to the A5H2 action. Both of those actions do tolerate lower port pressure actions to a degree.
If you find yourself using ammo that will not support these actions, you may want to look into a different ammo selection. There's a lot of stuff out there, some good, some bad, and a lot of in between.
Is there an issue using the lower mass buffers that will run the problem ammo when using 5.56? That depends on the degree of the change, I personally do not do it. It may work okay for an end user that will not use a can.
I tend to side towards feeding the fuel that system would normally need and not make a compromise for cheaper fodder that tends to make the system less balanced from its intended use.

Pappabear

04-01-16, 03:19

I run A5 on everything. However, that gas system makes the gun run so smooth, its hard to improve.

On go KAC or no KAC, I think the gun is a fair price. By the time you consider the Trigger and ambi controls and the quality of the system. Its a very solid purchase for the dollar.

phaseshift

04-02-16, 21:34

Decided to go with this below

http://www.bravocompanyusa.com/Stock-Hardware-Mounting-Kit-Mil-Spec-p/bcm-stock-hardware-kit.htm

And popped my Kac buffer in, I should be good right?

phaseshift

04-03-16, 16:30

Brahmzy

04-03-16, 17:13

With Wolf Gold?? That's full power 556 ammo.

w3453l

04-03-16, 17:21

Did you have the KAC H2 buffer in? I don't mean this to sound condescending, but did you clean and lube the gun before shooting?

My 14.5 mod 2 with KAC H2 buffer ran fine. I did shoot a box (150 rounds) of Lake City M855 5.56 first. After that I shot a few boxes of Wold Gold, it couldn't be too much more than 100 rds if that. I did have one stove pipe with the Wolf Gold, but couldn't repeat it. It's hard to say whether it was ammo, mag, or gun related but I'm not worried about it.

tom12.7

04-03-16, 18:19

Okay have an issue, used my Kac buffer today 100 rounds of wolf gold then the bolt started to not lock back and also started to fail putting a round in the chamber, it would go bang and click so I'd have to rack it back.

Wait a minute, you replaced an A5H2 with a carbine action H2 and expected improved function? That would be a rare event.
Make sure you cover the basics first, then go from there.
Something to think about though is that the KAC doesn't necessarily need domestic LC like ammo to run, but it can run that better than others. If you want to run some other ammo, a 6920 could be a starting point.
Some ammunition has the potential to run better with the increase in time duration of the applied gas port pressure, some do not.
My personal preference is to feed the base system with ammo that works well, no matter what the base platform is. If your ammo selection runs better with brand "X" than "Y", but all you want to buy is "Y", then buy a base system that suits that better. If you buy brand "X", then buy a system that suits its potential.

phaseshift

04-03-16, 18:25

Wait a minute, you replaced an A5H2 with a carbine action H2 and expected improved function? That would be a rare event.
Make sure you cover the basics first, then go from there.
Something to think about though is that the KAC doesn't necessarily need domestic LC like ammo to run, but it can run that better than others. If you want to run some other ammo, a 6920 could be a starting point.
Some ammunition has the potential to run better with the increase in time duration of the applied gas port pressure, some do not.
My personal preference is to feed the base system with ammo that works well, no matter what the base platform is. If your ammo selection runs better with brand "X" than "Y", but all you want to buy is "Y", then buy a base system that suits that better. If you buy brand "X", then buy a system that suits its potential.

The a5h2 bufferweights about ~5.3oz and the Kac buffer weights ~4.6oz. I ran about 300 rounds of xm193 when I first fired it, then I had a good deal on 1k wolf gold which a lot of KAC owners said theirs ran fine.if I have to run xm193 all the time that's fine with me but with others having great success with wolf gold I figured i would I've it a shot.

phaseshift

04-03-16, 18:33

With Wolf Gold?? That's full power 556 ammo.

Wolf gold I have is 223

http://www.sgammo.com/product/223-556mm-ammo/1000-round-case-223-rem-55-grain-fmj-brass-case-non-magnetic-wolf-gold-ar-15-

tom12.7

04-03-16, 18:35

What would make you think that an import ammo repackager is as consistent as domestic LC 5.56 offerings? Have you looked at the suppliers for Wolf? How could they possibly bring a consistent product to market? With so many variables, it does not seem that that it could be feasible overall, just too many variables.

tom12.7

04-03-16, 18:49

Wolf gold I have is 223

http://www.sgammo.com/product/223-556mm-ammo/1000-round-case-223-rem-55-grain-fmj-brass-case-non-magnetic-wolf-gold-ar-15-

With most import ammunition, I've found that I do not trust the peak pressure ratings for .223 or 5.56. They could be okay, or maybe not, it's a roll of the dice. Port pressures can be all over the place. Some can work well, others not, just depends on the mix of parts.
What's a few cents extra per round in the grand scheme of things? I tend to caution folks who find ammunition for "a deal", if it worked so great, it would not be that cheap. Normally it is cheap because nobody else will buy it, for good reasons. Simply part of supply and demand.

jstalford

04-03-16, 19:05

It may be 223 but it's not weak like pmc bronze. Closer to xm193

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phaseshift

04-03-16, 19:29

It may be 223 but it's not weak like pmc bronze. Closer to xm193

Sent from my iPhone using Tapatalk

Thus, the reason I bought it cause a lot of the SR15 owners had good experience with it, so I was expecting similar results

tom12.7

04-03-16, 19:37

Weak in what way? There are many examples that may have higher or lower port pressures for a given peak pressure. Peak pressure does not mean a given port pressure is the same for different port locations, it does not work that way..
Granted PMC ammo did make guns that run stop running. That is not a fault of the base gun, just a wrong application for the provided parts.
It may be better to look into what happens for the pressure events for the selected ammunition.

Serlo II

04-07-16, 18:16

I really enjoy my rifle, it's the best AR15 platform rifle I've fired. I only have a couple of thousand rounds through it but it shoots very well and is perfectly reliable.
I recommend the SR15. It's a fair price for what you get.

http://i1174.photobucket.com/albums/r616/Undefineduser45/Gunk/IMG_1140_zps84djr4dh.jpg (http://s1174.photobucket.com/user/Undefineduser45/media/Gunk/IMG_1140_zps84djr4dh.jpg.html)

MadAngler1

04-24-16, 16:09

Thinking about getting the 16" M-lok version of the mod 2 with their latest QDC suppressor vs a scar 16 with a surefire 556 socom. Which one runs better for carbine classes like Gunsite, etc? Anyone have experience with both platforms?

Edited to add: Mainly interested in how well each runs suppressed

tom12.7

04-24-16, 16:47

MadAngler1

04-24-16, 23:28

Are you able to manipulate a SCAR base platform as well as an AR base platform?

I haven't had the chance to really run my scar-17 like I have with my AR in a course or a 3 gun match yet due to work contraints the past couple of years. I would venture to guess that I could run the AR faster than a SCAR 16.

lennyo3034

06-02-16, 08:33

The a5h2 bufferweights about ~5.3oz and the Kac buffer weights ~4.6oz. I ran about 300 rounds of xm193 when I first fired it, then I had a good deal on 1k wolf gold which a lot of KAC owners said theirs ran fine.if I have to run xm193 all the time that's fine with me but with others having great success with wolf gold I figured i would I've it a shot.

Whoa Whoa Whoa...Stop shooting immediately!

The A5 buffers and standard/KAC buffers are NOT interchangeable. The A5 buffers are longer to accommodate the longer buffer tube length. If you are running a standard carbine or KAC buffer in an A5 tube, you are damaging your lower receiver. The shorter carbine buffer is not coming into contact with the rear of the tube as its supposed to. Instead your carrier key is likely hitting the top of your lower receiver. I would be willing to bet your function issues are a result of a damaged key.

If you are running the Kac buffer in a standard carbine tube, then ignore this.

skp

06-02-16, 10:52

Whoa Whoa Whoa...Stop shooting immediately!

The A5 buffers and standard/KAC buffers are NOT interchangeable. The A5 buffers are longer to accommodate the longer buffer tube length. If you are running a standard carbine or KAC buffer in an A5 tube, you are damaging your lower receiver. The shorter carbine buffer is not coming into contact with the rear of the tube as its supposed to. Instead your carrier key is likely hitting the top of your lower receiver. I would be willing to bet your function issues are a result of a damaged key.

If you are running the Kac buffer in a standard carbine tube, then ignore this.
Relax. He has a KAC upper on a Noveske lower with an A5 tube.

https://www.m4carbine.net/showthread.php?172799-Knights-SR15-E3-Carbine-MOD2-and-223-questions&p=2294728#post2294728