Inspect it.
Starting at the muzzle...crown...muzzle device...torque spec on device...damage.
Bore condition. Inspect clearly, clean it properly, dry it.
Chamber condition...same.
Bolt...factory? Modified? Headspace? Lugs? Lug seats? Extractor/Ejector? Handle timed correctly? Extraction in line with specs?
Action- Trued, square, mount is correct, bolt is not binding, bolt raceways are straight and not twisted, no odd mods for magazines?
Stock...bedding, interface, free floated barrel?
Ammo- Gold Medal?