Comparison Photos of Ak variant bolt carriers and Bolts. LEFT-RIGHT
The ak74 bolt carrier has the lightening cuts similar to an AKM bolt, the SLR107 uses an AK47 bolt and bolt carrier (this is the main difference between Russian and Bulgarian Arsenals.) the Yugo BCG is made from stainless.
The galil is basically an AK47 BCG but it has an upturned handle, also because Galil’s use a smooth gas tube they have a “flower” design around the piston to keep the piston centered, in contrast to an AK which uses a crimped gas tube.