SCAR 17S quality issue

2wheelwander · May 22, 2025, 11:37 AM

Bought a 17S a few years ago. Decided to suppress it, yes I know FN's stance on this, as ludicrous as it is. Installed the online recommended flash suppressor to host the can, which I installed myself.

Put a Sandman can on it an immediately had a baffle/endcap strike. Sent the can back to Dead Air and they did warranty it and sent it back rebuilt. Dead Air sent along another identical flash suppressor (not sure why but I apprecaited it). Took everything to my LGS to have it professionally installed and checked before I screwed something up again and had another strike. This is where it got interesting.

We went through both flash suppressors and using their rods checking for concentricity the can was always leaning typically to the 6 o'clock position. Using shims we could change that but it never set perfect. They put my can on 2 different new Daniel Defense AR's - perfect concentricity. LGS then ordered a flash suppressor I was unaware of that was made specifically for the 17S hosting a Sandman can. Looks like an AR-A1 duck bill flash hider. $80 later, the problem still existed. No matter what we did, shims, 3 different can mounts, it was impossible to obtain anything close to decent concentricity and eliminate the possibility of another strike. The rod was always favoring one side or another. We both agreed the rifle was the problem.

I took my SCAR to my local gunsmith/machine shop. They immediately verified FN's threads were not square to the barrel

. Paid $3200 and FN couldn't thread the barrel square!

Left the A1 style flash hider with them with instructions to cut the barrel down and pin/weld the new flash suppressor in place to get me to 16". I'll loose an inch of barrel or so, but that isn't going to make a hill of beans difference. I'd rather have that than extend things unnecessarily. Plus, keeps me out of SBR territory.

Anyway, just wanted to pass this along. Shame on you FN! I get everything mechanical and human intervention has the chance to have errors, but for a reputable manufacturer at this price point not to thread the barrel square is inexcusable to me.

Before everyone gets up in arms about sending it back to FN, both local gun stores shared the same opinion of FN's customer service - it sucks. They both had choice words about FN's treatment of their customers regarding warranty claims like this that are unfit for a gentleman's forum. Because of their shared advice, I decided it was in my best interest to just pay to have it done locally and quickly.

I do not see myself purchasing another FN product.

2wheelwander · June 5, 2025, 03:42 PM

Need to chime in here and correct the above information. The barrel was NOT suspect. At the above mentioned machine shop/FFL, their gunsmith really went over it. The barrel had no more than .002" runout from end to end. BRAVO FN!!! He coudl not check the inside/bore of the barrel from end to end. This was the exterior measurement. Also checked the 3 different flash suppressor mounts I brought him. They were machined perfectly.

This brings us back to Dead Air. He ended up using the original mount (not the 3 pronged/duckbill style). Using shims he was able to get things lined up. Haven't had a chance to talk to the gunsmith yet to get all the details, but he made it happen and test fired it.

Wanted to clear the air and correct a wrongful accusation on FN. Will post more after I'm able to talk to him.

Daren Thompson · June 6, 2025, 08:27 PM

I have all the SCAR rifles except the 15p. I have suppressed them all and installed an EC Tuner brake on one of my 17s. The issue is the thin profile barrel doesn’t give a shoulder for the hider or tuner brake to rest on. Parker Mountain Machine makes a shoulder to install. This will most likely fix your issue. The military issued rifles have specific suppressor/flash hider combos that will work with the thin profile.

May 22, 2025, 11:37 AM	#1
2wheelwander Senior Member Join Date: January 9, 2018 Posts: 622	SCAR 17S quality issue Bought a 17S a few years ago. Decided to suppress it, yes I know FN's stance on this, as ludicrous as it is. Installed the online recommended flash suppressor to host the can, which I installed myself. Put a Sandman can on it an immediately had a baffle/endcap strike. Sent the can back to Dead Air and they did warranty it and sent it back rebuilt. Dead Air sent along another identical flash suppressor (not sure why but I apprecaited it). Took everything to my LGS to have it professionally installed and checked before I screwed something up again and had another strike. This is where it got interesting. We went through both flash suppressors and using their rods checking for concentricity the can was always leaning typically to the 6 o'clock position. Using shims we could change that but it never set perfect. They put my can on 2 different new Daniel Defense AR's - perfect concentricity. LGS then ordered a flash suppressor I was unaware of that was made specifically for the 17S hosting a Sandman can. Looks like an AR-A1 duck bill flash hider. $80 later, the problem still existed. No matter what we did, shims, 3 different can mounts, it was impossible to obtain anything close to decent concentricity and eliminate the possibility of another strike. The rod was always favoring one side or another. We both agreed the rifle was the problem. I took my SCAR to my local gunsmith/machine shop. They immediately verified FN's threads were not square to the barrel. Paid $3200 and FN couldn't thread the barrel square! Left the A1 style flash hider with them with instructions to cut the barrel down and pin/weld the new flash suppressor in place to get me to 16". I'll loose an inch of barrel or so, but that isn't going to make a hill of beans difference. I'd rather have that than extend things unnecessarily. Plus, keeps me out of SBR territory. Anyway, just wanted to pass this along. *Shame on you FN!* I get everything mechanical and human intervention has the chance to have errors, but for a reputable manufacturer at this price point not to thread the barrel square is inexcusable to me. Before everyone gets up in arms about sending it back to FN, both local gun stores shared the same opinion of FN's customer service - it sucks. They both had choice words about FN's treatment of their customers regarding warranty claims like this that are unfit for a gentleman's forum. Because of their shared advice, I decided it was in my best interest to just pay to have it done locally and quickly. I do not see myself purchasing another FN product.

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June 5, 2025, 03:42 PM	#2
2wheelwander Senior Member Join Date: January 9, 2018 Posts: 622	Need to chime in here and correct the above information. The barrel was NOT suspect. At the above mentioned machine shop/FFL, their gunsmith really went over it. The barrel had no more than .002" runout from end to end. BRAVO FN!!! He coudl not check the inside/bore of the barrel from end to end. This was the exterior measurement. Also checked the 3 different flash suppressor mounts I brought him. They were machined perfectly. This brings us back to Dead Air. He ended up using the original mount (not the 3 pronged/duckbill style). Using shims he was able to get things lined up. Haven't had a chance to talk to the gunsmith yet to get all the details, but he made it happen and test fired it. Wanted to clear the air and correct a wrongful accusation on FN. Will post more after I'm able to talk to him.

June 6, 2025, 08:27 PM	#3
Daren Thompson Senior Member Join Date: December 6, 1998 Location: Elizabethtown,KY,USA Posts: 460	I have all the SCAR rifles except the 15p. I have suppressed them all and installed an EC Tuner brake on one of my 17s. The issue is the thin profile barrel doesn’t give a shoulder for the hider or tuner brake to rest on. Parker Mountain Machine makes a shoulder to install. This will most likely fix your issue. The military issued rifles have specific suppressor/flash hider combos that will work with the thin profile.