GunKraut
Senior Member
The fact its a fully machined receiver is enough The proof mark is sometimes on the rear tab of the receiver . Its a real late 44 rifle O block in Phosphate.
Some show up in 45 that are blued due to being earlier made and rejected then used in 45 with the rail milled off.
Finding a fully machined in Phosphate isn't easy.
This receiver may have been returned to Zella-Mehlis from Buchenwald as concentration camp production stopped after the 1944 allied bombing raid.