Slightly OT
Having changed a few M1 Carbine barrels in the past and remembering they used index or alignment marks on the bottom of the barrel and front of the receiver, I looked up this old Government Technical Order: Army Tech Manual TM9-1276, Dept of the Air Force Tech. Order 39A-5AD-2, dated 17 Feb 1953, to quote page 121, para. 59a. ASSEMBLY. Replacing Barrel. Select proper barrel and receiver combination so that about 1/16" draw is obtained when assembled. Screw the receiver on the barrel with wrench 7113308 (fig 9): draw up receiver until alignment marks on barrel and receiver (*Fig 92)coincide. Then determine that the flat surfaces on bottom of barrel and receiver are parallel. Check this by indicator or placing two bars, about 10" long, in position as illustrated in fig 93; and sight over the edges. When the two bars lie parallel, the barrel and receiver are in exact alignment for proper functioning.
Note: After installing barrel on reciever, adjust and check the head space as described in paras. 57d abnd 58d.
*Fig 92 shows lines on front of receiver and bottom of barrel in alignment.
My .02, In mass production, If we used alignment marks for replacemnt and new manufacture, did we copy other countries' methods or start our own?
Further might the alignment of Luger barrels require an additional check as outlined for the M1 carbine above, which could result in a slight misalignment of marks.
In the US Military there are normally 3 Levels of
maintenance: Organizationl, Field and Depot. Replacement of weapon barrels is normally restricted to Depot level maintenance.
Would have sent pictures but have no scanner or camera capability.
Regards
Ken D
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