Owners of BOTH: SF FA556K and AAC M4 2000

General Firearms NFA
1

Hello All,

I think I have narrowed my choices down to two suppressors. For me, I am looking for minimal and repeatable POA/POI shift, good sound suppression, and quality and durability. I realize I will not go wrong with either of these cans…

Just so you know…I will be shooting this on a LMT 10.5" and a Noveske 10.5".

I was just curious to see if there were any of you out there that have OWNED both the Surefire FA 556 K and the AAC M4 2000. My goal is not to start a discussion between supporters of both cans regarding which one is better, but to see if there are any of you out there that have OWNED or T&E’d both of these side by side.

For those people, shooting side by side, is there a difference in sound? What about POA/POI shift (again, shooting same guns side by side, same time, same environment, ammo, etc.)…

Are there any other issues which would sway you to use one or the other?

I appreciate your input and help in advance.

Maybe this has already been answered, if so, please send the link as I did not find it in my search.

2

I have second hand knowledge of a US Special Operations Unit that did extensive testing and chose the Surefire unit - from what I understand It was not even close in terms of durability

I own both Surefire 5.56mm cans (long and short) and IMO they are the best of their type available ; #1 reason why is minimal to no zero shift on most weapons

Hope this helps

LAV

3

Minimizing POI shift was one of the SF goals when they set out to do silencers.

POI shift will be unique to each individual’s set up. I have a weird POI shift on my AAC M4-1000. It’s actually 1 MOA up on a 14.5" M4 profiled barrel.

If you can afford and find a SF can, go for it. For me, I can’t justify that much money on a light duty, recreational item.

4

Yeah, the choice between an M4-1k and a SF can is quite a bit of money, that’s for sure.

Thanks for your input Larry. Was it the 1K that was tested or the 2K? Maybe it doesn’t matter? Just curious.

5

My 556K has no noticeable POI shift at 100 yards. I have no experience with the AAC model. Wally

6

Mine has zero. Let me ask you, what adapter are you using?

C4

7

The amount of shift from unsuppressed to suppressed fire from my AAC M4-2000 Mod 07 is within the 3.2MOA dot of the the Aimpoint T1 that’s mounted on my 10" SBR…YMMV. I’m not a good enough shot to see a shift using an Aimpoint.

8

Thank you very much Mr. Vickers! That was exactly what I was looking for and that made my decison really easy! I really appreciate your quick response.

Thanks to everyone else as well for your responses.

chris

9

Got M4,

Interesting…well, if you are not seeing a shift, than I for sure will not!

For those groups, do the suppressed groupings stay in a general area, or a tighter pattern than the unsuppressed? I guess what I am wondering is if the index of their suppressors changes the poi in a consistent manner. A better questions would be, at 0-50 yards do you see a consistent grouping with the suppressor when taking it on or off?

I know that you sent yours and AAC replaced yours with a Mod 7, and I think I have read your reviews on the new one but how is it holding up?

Thanks for your help!

10

C4, I am using the original mount that came with it. Flash Hider not the compensator. Not sure of the part # though. Why do you ask?

Wally

11

For what it is worth, decibel numbers are way over rated. My hearing is fine and I can’t tell the difference between the older m4-2000, SF M4FA and KAC NT4. They have different tones but I didn’t notice one to be louder than the other.

FWIW, I have the Surefire but would consider the AAC. I bought what was in stock. I will recommend Surefire based on my experience with mine.

12

I do find that the groups tighten up while suppressed, meaning more accurate vs. unsuppressed. I’ve also changed from a 50/200yd zero to a 100yd zero with my 10" SBR. With 77gr MK262 Mod 1 I find that it’s a more practical zero for this gun. For my other ARs I still use a 50/200yd zero.

The can is holding up very well, it fits the 2 Blackout mounts I have much better than the original mount (Phantom type) that came with it.

13

Same here. We did a 50 yard POI shift check just a few weeks ago. The results were the same as I’ve seen in the past. Much tighter groups.

14

Roger. You are running the 212A. I am not a fan of these as much as the 556K MB as I believe that they do not allow the can to lock up properly. The majority of the issues I have seen with the SF can are directly related to this adaptor.

C4

15

Let me preface this by saying that this is totally based on MY impression of reading multiple reviews by various owners of both cans.

The advantage appears to go to the Surefire cans with regards to POI shift, but there have been more than a few reports of difficulty in removing the can due to fouling after heavy use.

The advantage appears to go to AAC with regards to the mount and ability to remove when the can is fouled, even more so with the new 51-tooth mount on the 2008 spec cans, but there may be more POI shift.

My personal preference, on a 10.5" barrel, is for the AAC, largely because I just like their mount so damn much. Samples I have seen mirror Robb’s experience with regards to shift.

16

My 556K is currently stuck on my 10.5!!! I am not sure as to how to remove it without damaging it…Any ideas? My plan was to shoot 2-3 rounds and try to remove it when it got some heat into it. Repeat as required…I even bought a thicker oven mit to help!!!

C4, if I ever get this thing off, do you have any on the MB’s?

By the way, the Flash Hider was the only mount available when I originally purchased the suppressor. I have not given the mount much thought until recently.

Thanks,

Wally

17

Your K can is stock on your weapon? That is a new one!

I have the MB’s in stock.

C4

18

Yes, oven mitt (or something of that nature), shoot until hot, remove. We’ve had one or two guys get Halos stuck and that’s how they got them off.

19

I have not read any reports of POI in the new 08 M4-2000 can, which I assume is what you would be getting. They only started shipping a few weeks ago.

20

FWIW, I have a M42K that was upgraded to 07 specs and ran it through last Decembers Pat Rogers class in SC and at the end of each day I had a fun time trying to get the can off. I cannot imagine how much trouble it would have been to leave it on through the whole class, and try to remove it at the end of 3 days. I would clean the flash hider and inside of the can every night so hopefully it would come off the next day. Almost all cans will have this happen with that much carbon, so it is not like there is any particular brand that is immune to it. I remember at the same class, there was a mil guy there with a gov.'t issue NT4, and although he didn’t run the can through the class, he said he had the same issues with his set up as well.