I have several tier 2 & 3 AR 15s, LMT is my #1 . I want to buy a KAC SR15, a Colt 6920 and a BCM 16" mid-length. I am looking to replace the #1 slot with one of these 3. I really like the KAC (I like all 3 really, but only can afford 1 now). What does the KAC SR15 offer that the others dont? The cost of the SR15 is about the same as the BCM 16" & 6920 combined. Any advice 
You are not really comparing apples to apples though. This is the way I figure it. SR-15- $2000 and less brand new
6920- $1200 add an equal trigger- + 200 add the sopmod stock+ 200
add a rail DD Omega + 250 you are $ 1850 and still do not have the gas system the SR-15 has or the bolt. If you do not need all the extra stuff the Knights has, then yes it is not worth it. If you plan on adding that stuff down the road just get the Knights. At least this is how I justify my purchases!
Yes. If you look past the sticker price and start to break out the features that are included, it surpasses most other comparable rifles similarly equipped. And, it is a KAC.
As stated if you break the gun down part by part the KAC is actually the most economical.
If all you want is a bare bones but quality gun AND dont want to spend money on extras then the BCM or Colt is a better buy for you.
With the KAC you are getting a 500 rail system, 200 dollar rear buis, 200 dollar trigger, 200 dollar stock, a unique lower with some cool features, arguably the best AR bolt design on the market, etc. But you need to be happy with what it comes with or sell something off like trigger and/or stock. I replaced mine with a CTR, and sold the stock so I saved $100 off the price right there.
My SR15 is my favorite gun, and Im very happy with it.
Somewhere around here there’s a post where I added up everything you get in the SR15 and compared it to an equal build from
BCM and the prices were almost identical, and they don’t factor in the E3 bolt which isn’t really something you can put a price on.
If the features of the SR15 are what you want/need then it is actually a bargain.
this brings up a good point, while the gun itself is a good deal I think you might be shooting yourself in the foot for future parts by having a proprietary system. But that isnt something for everybody, plenty of people are fine with LWRC and other rifles.
If I get one, I will certainly try and buy an extra BCG or atleast bolt with it.
Standard carrier will work. I would want three things:
- spare extractor & springs
- spare complete bolt
- spare gas tube (it is a proprietary link)
FWIW, people like the Magpul boys are getting 20k+ rounds on the OE equipment reportedly.
This is kinda funny to me as I have a 6920 and a SR15. I still need to put more money into my Colt to make it feel and shoot like the KAC. The Colt without a doubt is a great rifle, but believe me, just get the KAC. You won’t look back. 
Here is a good recent thread regarding the KAC SR15…
If I could only have one AR, it would be a SR15E3, by far the best out-of-the-box package currently on the market.
The SR15 is sexy kit. I’m not entirely sure about the price, but the buyer is getting one solid carbine at the end of it all.
What’s there not to be sure of?
BCM BFH 16" Upper Receiver Group w/ Knight Armament Company URX II $1150
BCM Bolt Carrier Group (MPI) - Auto $140
BCM4 Lower Receiver Group $360
LMT SOPMOD Stock $200
KAC Trigger P/N 98032 $320
KAC Flip-Up Rear Sight 200-600 Meter $200
that’s $2,370 without the E3 features.
It can, be made similar (again without E3 or ambo) for less, quoting myself from here
Finally, when pricing these things you need to make sure you’re comparing apples:apples. You need to start with a BCM BFH 16" w/ DD Lite 12.0 at $949 (note that BCM does sell their uppers with the KAC URX but it’s $300 more. From there you need to add a BCM BCG for $150, a charging handle for $20+/-, and a set of MBUS (since we’re going on the cheap) for $100. That gets you to $1220 for a complete upper.
Moving to the lower, you’re going to start with a BCM at $330 without stock, add an Emod for $120 (going for that "same function, reduced cost, the SOPMOD is another $80), and a Geissele AR15 Super Semi-Automatic Trigger for $170. That brings you to $620 for the complete lower and up to $1840 for the complete gun. Bearing in mind that you still aren’t getting the E3 features.
I found a KAC SR15 listed on Gunsamerica for $2200, which is a $350 premium over the package above. What you’re getting for that premium is the E3 bolt features, the ambi lower controls, and what is probably a lighter package overall. Put a set of Troy BUIS and the SOPMOD stock on the BCM and you narrow that gap even more.
The value is not the issue. It’s the sticker shock and if I am willing to drop $2300 on an AR15
I was just holding an SR15 the other day. I was instantly enamored with it. Since, I’m been evaluating firearms to ditch to help fund acquiring one.
Well, like I said, it’s only a good value if it combines features that you want. While I absolutely love the gun, I’ve gone back to a more minimalist approach on my personal guns and so the SR15 would only sit in the safe if I bought one.
Thanks everyone for the input. Guess Im unsure about filet mignon because everyday I eat hamburger, seems I dont know what I am missing. You make a great point with the proprietary parts that should be bought & stored for future replacement. Thanks for the links, I still have more articles to read but I think this might be the year of the SR15.
A few places are selling them at $1999 now. With shipping, and my dealer transfer fee it was less than 2100 OTD.
I asked the question a while ago but never got an answer. I know a standard AR15 bolt cycles just fine in the E3 barrel ext, and Im wondering if a standard bolt would then be able to fire just fine too. Curios of KAC ever has done any testing on this.
I dont even like shooting my other ARs since I got my SR15s.
They are worth it.
Are you sure about that? I was under the impression the CARRIER was a standard one with the bolt being proprietary…
Also, arent the cam pins enlarged on the SR15’s? Would this prevent the use of a standard AR carrier?
No the bolt carrier is the same as a standard AR15. The cam pin, and bolt are the proprietary parts. The cam pin is smaller diameter where it goes into the bolt so the bolt is actually thicker. One of the big weak points in the standard bolt is the cam pin cut out area so obviously having it thicker with the E3 bolt will reduce the chance of failure. The 2nd major weakness is in the lugs on the bolt itself. The E3’s lugs are rounded which adds additional strength.
What I was talking about using a standard bolt in the E3 barrel extension. I put a standard BCG in mine, and it certainly cycles just fine. I was wondering if KAC or anyone else ever tested this so a standard bolt can be used if absolutely needed. Im not about to guinea pig a 2k gun but I thought maybe KAC got a hair up the butt, and shot a standard bolt in any of their testing.
Not compatible , will not work. E3 bolt assy ,cam pin,firing pin and bbl extension are only compatible with each other .