MP40 Barrel Nut Retaining Washer Installation Instructions

[hatrick]

Can anyone explain the proper procedure for installing the thin barrel nut retaining washer and getting it properly aligned and getting the tabs peened to properly lock the barrel retaining nut. Is there any specific tightness the retaining nut should be tightened to or is basically as tight as possible (within reason)? Does it matter which way that thin washer faces?

Any help would be greatly appreciated as I don't want to damage anything since all the numbers are matching. Very odd that it is missing to begin with.

Thanks

[TSMGguy]

Photo of barrel nut and locking washer that have not been tampered with. Reproduction MP40 barrel nut locking rings have been available in the past. It looks to me that the factory used a small square tapered punch to stake the ring.

The MP40 is of mostly of pinned construction. Staking was used extensively, which prevented tampering at the user level. An MP40 that has not been disassembled past field strip is a rare bird today.

 

Edited December 12, 2023 by TSMGguy