Legal: where does ATF or LE measure rifle

[DannyBMW]

barrel length from? Is it the receiver face or the bolt face. I have an STG and I want to cut to 16.25" including DSA brake and I want to make sure I'm legal on length.

TIA
Danny

[Kent]

Legally, barrel leangth is measured from the breech or bolt face to the end of the barrel. Easiest way to do it is close the action. Stick a cleaning rod down the barrel from the muzzle until it stops at the bolt face. Mark the rod at the end of the barrel. I always add 1/4 inch for insurance.