Swiss SIG 553 pistols have hit the US market

[Mike Miller]

I have a 551 with a removable flash hider. Are there any quick attach suppressor mounts that are narrow enough to remove the gas regulator and gas tube with the suppressor mount still attached?

[JoshNC]

I have a 551 with a removable flash hider. Are there any quick attach suppressor mounts that are narrow enough to remove the gas regulator and gas tube with the suppressor mount still attached?

- Suppressor that mounts A2 FH...Gemtech, AAC, B&T Rotex V (not available in the US yet)
- KAC NT4
- maybe KAC CQD with the timing pin clocked at 6 o’clock.

Unless you make your own suppressed position in your gas valve, I think you will find the 551 is way over gassed with a can.

[SteyrAUG]

Unless you make your own suppressed position in your gas valve, I think you will find the 551 is way over gassed with a can.

My 551 Swat (14" barrel) runs a HALO just fine. I haven't noticed any problems, probably smoother than my Colt 6945.

[Bret]

My 551 Swat (14" barrel) runs a HALO just fine. I haven't noticed any problems, probably smoother than my Colt 6945.

Is it over gassed unsuppressed or does it only toss spent cases a few feet? My 551LB is over gassed unsuppressed (like most AK's). I can't imagine suppressing it without having a smaller hole in the gas valve.

[SteyrAUG]

Is it over gassed unsuppressed or does it only toss spent cases a few feet? My 551LB is over gassed unsuppressed (like most AK's). I can't imagine suppressing it without having a smaller hole in the gas valve.

I honestly don't even notice either way. I notice some 7.62 AKs are overgassed and boy I'd hate to run some of them suppressed. The only SIG I ever had that might have seemed overgassed was my 552 and even that wasn't terrible or anything.

[JoshNC]

I honestly don't even notice either way. I notice some 7.62 AKs are overgassed and boy I'd hate to run some of them suppressed. The only SIG I ever had that might have seemed overgassed was my 552 and even that wasn't terrible or anything.

My two 552s absolutely SUCK suppressed. I’ve used a SF 762 SOCOM RC, which was okay but obviously way overgassed. And a AAC M4-2000, which as expected (high back pressure can) was atrocious. My 551s won’t see any suppressor because I don’t own a can that mounts to the SIG flash hider. Nor would I want one messing up the finish on my previous collectibles. Ha. Now had I kept one of the LE trade-in 551s with lots of honest wear, I wouldn’t feel bad about attaching a can to the already worn FH.

For me, SIGs are already heavy and overgassed. I have almost no interest in suppressing any of mine. Same goes for my FNC. It won’t ever see a suppressor. ARs, SCAR with gas jet dialed in, and AUG are all better suppressor hosts than the 55x.

A 553 short barrel with suppressor gas valve still functions without a suppressor with the valve set to suppressed. #overgassed.

[SteyrAUG]

My two 552s absolutely SUCK suppressed. I’ve used a SF 762 SOCOM RC, which was okay but obviously way overgassed. And a AAC M4-2000, which as expected (high back pressure can) was atrocious. My 551s won’t see any suppressor because I don’t own a can that mounts to the SIG flash hider. Nor would I want one messing up the finish on my previous collectibles. Ha. Now had I kept one of the LE trade-in 551s with lots of honest wear, I wouldn’t feel bad about attaching a can to the already worn FH.

For me, SIGs are already heavy and overgassed. I have almost no interest in suppressing any of mine. Same goes for my FNC. It won’t ever see a suppressor. ARs, SCAR with gas jet dialed in, and AUG are all better suppressor hosts than the 55x.

A 553 short barrel with suppressor gas valve still functions without a suppressor with the valve set to suppressed. #overgassed.

Honestly my 551 (LE trade in pre sample) isn't any worse with a suppressor on it than any LE6920 with a suppressor in terms of weight to the front. My 6920 is the one I don't want to hang a full size can on, it's why I went to a 6945 (part of that consideration was also length).

[BoringGuy45]

I saw in Swiss Arms' catalog that they now have SG553s with aluminum upper and lower receivers (and not just the US lower). What are the thoughts on the strength and quality of the aluminum receivers vs the steel ones, particularly the upper receiver?

[JoshNC]

I saw in Swiss Arms' catalog that they now have SG553s with aluminum upper and lower receivers (and not just the US lower). What are the thoughts on the strength and quality of the aluminum receivers vs the steel ones, particularly the upper receiver?

I am not aware of any SIG 55x using an aluminum upper receiver, other than the US 522 (blowback 22lr) and the KAC SLiCK SCAR entry. Do you have a link to the SwissArms catalog you looked at?

[BoringGuy45]

http://www.swissarms.ch/en/sg-553-al-assault-rifle.php

Unless that's just the the lower they're referring to. Given the weight reduction, I was assuming it was both.