Your SGL31 complies with section 922(r) of US code since it contains ten (10) or fewer foreign made parts, even
when a foreign made magazine is installed.
The foreign made parts used in your rifle are as follows:
3. Trunnion Block
5. Bolt Carrier
6. Gas Piston
7. Magazine Body
8. Magazine Follower
9. Magazine Floorplate
The above list of foreign parts applies only to
the serial number marked in this manual.
Other rifles of the same model type may
contain a different number of foreign parts.
The addition of foreign made items or the
replacement of U.S. made items with foreign
made items may constitute a violation of
So I guess that leaves the other parts
as substituted parts aka compliance parts
trigger group 3 parts
stock 1 part
pistol grip 1 part
handguard 1 part
muzzle brake 1 part