Algodoo

Run on 800 Sim Frequency.

Use a roller locking recoil mechanism.

Stripper Clip style feed mechanism instead of a chain to simplify.

Enter fires
R retracts the clip if it jams (just tap R)
When clip is empty, hold R to eject the stub.

Use J-dewd's MG42 as a starting inspiration, all parts made by Halacar.