A rifle scope can only show you where the barrel was pointing when the shot broke. It cannot hold that relationship on its own. If the rings move, crush the scope tube or sit out of line then the point of impact will walk and it looks as if the optic has failed.
That is the problem Sportsmatch was founded to fix. Cheap rings on a recoiling air rifle or a centrefire tend to creep rearwards along the dovetail. A few millimetres of movement at the mount becomes a miss at 30 yards on a springer and a much larger miss at 200 yards on a hunting rifle. The scope turrets still click. But the zero does not stay put.
Accuracy in the field is a chain. Barrel and ammunition set the potential. The shooter has to do their part. Between them sit the rings. They have to clamp the tube evenly, stay put under recoil and keep the optical axis parallel to the bore. Aircraft-grade material and tight CNC tolerances matter here because a bad quality ring will damage the tube. A poorly machined scope mount body will cause the reticle to tilt if it moves. A loose clamp will let the whole assembly walk along the receiver.
That is why “no loss of zero” is a more useful claim than another half-mil of adjustment on the scope. You can buy a first-class optic and still print vertical strings if the mount is the weak point. Police and military units that specify Sportsmatch Picatinny rings are not doing it for the badge. They need the same point of impact after the rifle has been carried, knocked and fired hundred of times.
Practical checks before you blame the glass: confirm the rings, match the tube (1 inch, 30 mm or 34 mm), the rail (11 mm dovetail, 13 mm, 15 mm Tikka / Sako, Picatinny) and the objective lens diameter to determine which height of scope mount you require. Use the supplied hex key or a torque driver — over-tightening is as common as under-tightening. Fit an arrestor pin where the rifle has a hole for one. Then shoot a proper 5 shot group, not a single confirmatory shot.
If the group holds after a session and after the rifle has been taken in and out of a slip, the mount is doing its job. If it does not, change the rings before you change the scope. Sportsmatch mounts are made in Leighton Buzzard, guaranteed for life, and available from gunshops across the world.