New rimfire rifle, right?
Obtain parts diagram.
Disassemble all the way down to the firing pin.
Inspect, clean, reassemble, torque all fasteners to correct specs.
Before testing for accuracy, send 2 bricks of cheap ammo downrange,
cleaning the barrel after every 250 shots.
This is to polish the bore/rifling of the minor manufacturing defects.
Those burrs, bumps, fissures, tooling marks that rip up a bullets surface.
After the break in with cheap ammo, another serious cleaning.
Then test using 2 boxes of quality ammuntion, across a chronograph.
The first 20 are for warm up and scope adjustment,
the remainder are sent to record the chrony numbers and target results.
Decisions are based on the measured MV's and target results