PlinkBench
Checking the working build.

Parts

Completion hardware

Small parts a receiver needs: retainer, screws, buffer, pins.

Read the hardware research guide
Ruger10/22 Receiver Cross Pin SetPackage 2 pins
$4.00seen
Volquartsen FirearmsHex-Head Take Down Action Screw for 10/22 and 10/22 MagnumProduct number VC10TDOverall length 0.985 in
$6.75seen