Alloy steel replacement screws for the SCAR 16/17 upper receiver.
1 – M5x10 for the top of the rear trunnion – 3mm Allen
9 – M4x6 for the sides of the rear trunnion, the guide rail, the case deflector – 2.5mm Allen.
4 – M4x8 for the ‘teardrops’ and front sling plate – 2.5mm Allen.
4 – M4x12 for the side rails – 2.5mm Allen.
2 – M5x12 T25 Torx for the bottom rail – T25 Torx.
2 – Allen wrenches, 2.5mm and 3mm.
1 – T25 Torx wrench.
Only screws thing missing are the 6 custom ratcheting screws to mount the barrel and the front trunnion (these are an OEM item).
I presume that due to US mil-spec requirements for corrosion resistance, the OEM screws are stainless, and have a habit of stripping out. These alloy steel screws are stronger and won’t strip as easily.
NOTE: screws on a SCAR are held in place by green Loctite, which is strong, and requires that you apply heat to soften it prior to removal. Personally, I like to use a propane torch, but you need to be careful as there are some plastic parts which can melt or burn if you get them too hot or aim the torch wrong. I don’t guarantee this method will work for you.