[Timber Rattler]

In late 1944 enough theory had been worked out to allow the Luftwaffe’s Flak Command to issue a specifications for the gun.

That's true, but the Germans also found that energizing such a gun required a huge city-scale power station and was therefore technologically unfeasible. The captured project files were sent to the Dahlgren Naval Proving Ground after the war where Navy scientists looked at the concept again in the late 1940s but confirmed the German's findings. After HARP, the ballistics scientists at Dahlgren once again reviewed electric guns in the mid-1970s but again found that the technology was not there yet.

[U-238]

Thanks for the additional information. I did not know that

:)