A couple of years ago there was this forum online talking about FN SCAR 17 destroy optics, but there isn't any apparent evidence to support the claim.
Here is what we have found:
The overall discussion was about the forward bolt travel momentum slams very hard, and that causes sharp recoil harmonics to flex the top rail up and down. And that over time destroys an optic.
According to common sense engineering knowledge - The best place to mount the optic on the FN SCAR 17 is behind the charging handle slot where the receiver is solid & has more structural material.
This is the same concept for moving the red dot mount away from the AK top handguard cover because it vibrates a lot and it gets hot.
Features Geissele Super Precision ACOG mount - Dual Recoil Lugs To Prevent Shift
A rock-solid optic mount is the key to secure the optic on the rifle & retain zero. Another benefit of an optic mount is to absorb some of the recoil forces away from the main optic body.
While most people on this topic never published any convincing evidence, our SCAR 17 hasn't seen any problems while using high quality optics with good mounts.
What Could Be The Issue That One One Talked About
Poor airsoft grade optics can break on the SCAR for sure. These optics generally can't even retain zero & recoil impulse can easily knock out the optic internal circuits.
Always be sure to use high quality mounts and optics on a rifle like the SCAR. Some optics may be as expensive as a rifle or more, but legit products are made to perform.
Features Scalarworks LEAP Aimpoint Mount NV
We hope this give you some confidence in the FN SCAR 17s, and be sure to check out our SCAR 17 Optics guide.
Also check out the Scalarworks LEAP mount if you're using red dot sights on the SCAR 17S