This Ruger manufactured early variation recoil block bolt with the larger head (.465") is for the earlier model 44 semi-auto carbine and is in very good condition with light wear and possible some surface rust present. (file photo)
Note: Ruger model 44 semi-auto carbines with the following serial numbers have been observed with this part:
No Prefix: 61450, 64382, 66427, 95121, 107880 & 114926
100 Prefix: 100-13353
