Suppressing the SR-15E3

Dealers/ Manufacturers/ Regional/ Info Trash
1

I wanted to briefly revisit the SR suppression issue Robb/gotm4 touched upon in another thread, as I think this is something well worth discussing as these rifles continue to gain a well-deserved foothold in the mainstream market.

It obviously stands to reason that, because of the SR-15’s unique gas system geometry, associated operating pressures are going to be significantly different from standard carbine (or even mid-gas) systems. We would expect this to affect suppressor function to at least some degree, but the question is (a) how much is it effected, and (b) which cans seem to work the best/worst with this unique system?

For the sake of discussion, we’re talking specifically about the 16" version of the SR, vice the forthcoming 11.5" CQB SBR variant, since we know that the latter employs a more conventional gas system. On the full size SR, then, to what degree we have seen cans effectively tuned for use on this rifle? Does the typical Gemtech, AAC or SureFire perform well on an SR, or are certain modifications required to insure reliable operation? Is the standard KAC unit any different in this regard? Does this unique rifle require an equally unique suppressor solution, or is this much ado about nothing?

Since I’ve no current experience base from which to draw conclusions, I defer to others who may be a bit farther down this particular road. Granted, I suspect that our sample sizes will be relatively small, but if you’re running a suppressor on a standard SR-15E3 carbine, please share some of your impressions on (a) what you are using, (b) how it has performed to date, and (c) the conditions/loads involved in your testing.

Thanks!

AC

2

FWIW I’ve been told that Surefire, AAC and obviously KAC suppressors work well with the SR15s.
Which is why I believe it’s the mag catch slot in the lower being too low. It could be that the mag catch slot is milled at the lowest acceptable tolerance for height in the lower and that this particular upper is at the highest acceptable height from the lower for tolerance. Just my non-engineer mind thinking…but I think it’s the lower since the upper worked on a BCM lower 100% suppressed. Either way KAC did not test fire the complete rifle using a KAC can, they used another upper which changed the equation.

3

This is cross-posted from the other thread since it was my rifle that GotM4 is referring to when he discusses his experiences with a KAC gun running suppressed

I’m the VA Arms employee GotM4 is talking about that bought the KAC SR15E3

I initially loved the rifle…I put many rounds through it unsuppressed before my stamp came back, trouble free…it is light, well balanced, and ran like a top…extremely accurate…certainly a better rifle than I am a shooter

Then I tried to run it with my Gemtech G5 on it after I got my tax stamp back…

The rifle could not get through a single magazine without a failure to feed…

Initially I thought it may be the ammunition…so I tried out various things…GotM4 also suggested trying magazines that would vent better out of the bottom to relieve overpressurization…nothing…still failed, almost every time…

It was around this time that GotM4 suggested I contact someone he knew at KAC to see about helping me with the issue…we will call this person “X”…

X was initially very confused about my issues, and what was occurring. In order to help with this I went back to the range again and took many pictures of the failures, and the rounds as they occurred…

X still didn’t really have any answers as to the cause of the failures, and suggested I try different things…

I have to say that this was the first point of irritation I had with KAC…were I a VA Arms customer, and not an employee, I would have simply brought the rifle back to Bernie at VA Arms, and off to KAC it would have went…

But because of my status, and the working relationship between X, GotM4, KAC, and VA Arms, I went back out to the range…many more times…

During these trips I attempted multiple things…more ammo, more magazines, a PRI gasbuster charging handle, H1 and H2 buffers…pretty much everything I could think to do…no help…the failures still occurred…

During this whole process I kept up my contact with X…documenting everything I tried and it’s lack of success in fixing the problem…the response was still “try more things”…at one point I was asked if I had access to a select fire lower to test cyclic rates (I don’t)…but there was still no mention of returning the gun to KAC

Finally, GotM4 and I went to the range together one night…and tried some final things, including putting a BCM lower on the gun (something I should have and could have done earlier)…VIOLA! no issues…GotM4 tried swapping the mag release from the BCM to the SR15 lower, but the failures still occurred…it was at this time that GotM4 and I figured there was something out of spec with the lower…

Again I contacted X with my results…X was very earnest and eager to help but I got the impression that he was meeting resistance from above his head…

GotM4 at that point contacted someone we’ll call “Y”…who was higher up at KAC than X…GotM4 explained the problem to Y and suggested KAC take the gun back…X wrote me a few days later to say that as a result of GotM4’s contact with Y, the gun would be going back to KAC…and back it did go

on my dime…that’s right, after running easily 500+ rounds of ammunition through this gun trying to diagnose the problems…I PAID to ship the gun back to KAC…

Which is where it was for a few weeks with no contact at all or status update…

Finally I wrote X back inquiring for a status…

X told me the following:

  1. The gun had been spec’d out by the engineers and had definitely come back towards the “high end of acceptable” for the lower and mag catch…

  2. As a result of that, KAC was going to replace my lower

  3. X needed to get the gun once replaced, run it through it’s tests, and then I would have the gun within a week

Great…not the best process to get here, but that’s all I wanted…

So about 10 days goes by and my gun shows back up to VA Arms…

WITH THE SAME LOWER

The note in it said that a new upper had been put on the gun to test with a KAC suppressor, that no irregularities were noted, so the gun was returned AS IS…this after being told they were replacing my lower…

I wrote X back trying to figure out what had happened…

X wrote me back that he had been out of the office and that he was unaware that the gun had been returned to me like that…and that he was sorry things ended up that way…

and that was that…

it was at that point that I decided to cut away from the process and sell the gun…I am now out the initial outlay of capital for an extremely expensive rifle, several hundreds of dollars in ammunition to test a problem that, in my opinion, it should have been up to the manufacturer to test, the cost of shipping and, most importantly, a lot of time and frustration

I think the rifle is a fantastic gun, but I couldn’t recommend it to anyone simply because of the customer service issues were you to need them…X seems as frustrated as I (and GotM4) were at the way this turned out…and he seems like an extremely knowledgable and nice guy…but he also was unable to affect a positive outcome, and in the end, the way this went down was COMPLETELY unacceptable

i understand I am not a .gov or .mil consumer…but I am an employee for a distributor of the end product to the civilian market, and one who has access to considerable resources and contacts because of my position and my co-workers/friends (thanks GotM4)…

I can’t even begin to think of how incredibly fruitless this process would have been had I just been a consumer…

I understand my posting of this will likely piss a lot of people off, not the least of which are X and Y and the folks at KAC…

but I have been completely silent publicly about this process and have given KAC more than ample opportunity to fix the problem and keep me as a consumer…and they just didn’t do it…

needless to say, for those of you in the NoVA area…when and if you are ever in VA Arms…my recommendation will be for a BCM rifle…

4

Thanks, Trio. So, to keep things on point here, it doesn’t appear that the gas system of the SR really presents any significant supression challenges, but it is possible that there may be other some issues to confront. It is tough to tell with a sample size of one, but I am sorry to hear of your difficulties.

Given my confidence level in Robb’s knowledge base, I would be inclined to trust his wildest speculation above my own “hard facts,” but I’m still a bit less than clear on how a borderline/out-of-spec condition may have contributed in a material sense to the failures … especially if the gun had no issues when operated without suppression. Granted, this is an invalid comparison to at least some degree, given the many variables involved with supression, but in purely mechanical terms, I’m having difficulty envisioning what might have been happening here. Were you able to repeat these same results with any other type/model of suppressor by chance?

AC

5

Suppressed with the Gemtech G5 his KAC SR15E3 upper runs 100% on my BCM lower with a H buffer and standard CAR buffer spring.

Suppressed with the Gemtech G5 his KAC SR15E3 upper runs about 30-60% on his KAC lower with a CAR, H, or H2 buffer and standard CAR buffer spring. With all three buffers and firing 1 round per mag it will lock back on the the empty mag.

6

FWIW,
we’ve suppressed many KAC guns- SR15, SR25, etc and they have been very gtg.

I’m sorry for Trio’s odyssey above. That sucks.

7

I know that this may be an exception because of it being a KAC can, but running a QDSS-NT4 my SR-15 has been 100%.

8

Recently purchased an SR-15. I love it. I have surefires 212. Took the rifle to the range a couple of times. The last time I ran about 80 rounds through it with the 212 on. I was shooting XM193 55 gr federal. It functioned flawlessly. I could feel the difference in cycling between suppressed and nonsuppressed but no problems (and I fired 40 rounds very quickly to see if I could cause a problem). I haven’t changed out the buffer yet and I’m not sure because it’s pretty smooth. Next time out I will be trying it out with Hornady TAP 75 gr.

9

I’ve closed this thread.

This information I posted about this one particular KAC SR15E3 was never meant to be a dig at KAC nor any of it’s employees nor products they make. They make some fantastic gear.
This is about 1 particular KAC rifle which is having problems running suppressed with 1 particular Gemtech G5 suppressor and has been returned to KAC once. The original owner (Kevin aka/trio) put it on consignment and I bought it today. I’ll be testing it with my AAC M4-2000 Mod 07 which I’m told by employees of both KAC and AAC run well on SR15s. I’ll post up the results after shooting it later this week. I really want to see this rifle run suppressed. I’m praying that it runs just fine with my AAC suppressor, it’s an amazing rifle. With that said this thread is finished.

I’ve moved this thread to trash. I bought the rifle last night and will be shooting it with my AAC suppressor (M4-2000 Mod 07) on an AAC Brakeout. If it doesn’t work I’ll be in contact with KAC again to see if they can remedy the rifle. AAC and KAC claim that these rifles work with AAC suppressors.