Never been wrong in your life before? You need to go back and watch the videos and read the links again until it sinks in.
Meanwhile, you and I are severely de-railing a thread about DP-27 barrels. Which, I believe, only came with one barrel, so to be back on track barrels were not switchable in RL as there was nothing to replace the hot barrel with.
Jippo why is it I need to watch a video with a guy shooting a modified D-T 15 magazine without the locking latch and a new spring system ? (These are available for purchase today btw) What is it supposed to prove exactly ?
Truth is that all of this started when you claimed that there were a lot of D-T 15 magazines lying around back in the war, and that they could've easily been used with the MG34's, and as such was probably in wide spread use. I then informed you of why that wasn't the case, because:
a) The D-T 15 does not fit on the MG34 (unless you remove the locking latch)
b) The D-T 15 does not function properly even if you manage to make it fit because of a different spring system
c) There were hardly any MG34's around with the Trommelhalter top cover in the first place, and the only pictures available of it are from pre-war maneuvers.
Why you then continued to insist that the D-T 15 would work with the MG34 I have no clue as to.
I will leave this last comment from a good friend who actually owns several MG34's amongst other MG's, and gets to shoot them a couple of times a year (It was one of his guns that I tried twice before):
"No you're right, the original DT15 drums will not function reliably with the MG34, the spring tension is simply too tight and you can't adjust it like on the PT34. And yes, you would have to remove the locking latch from the DT15 first to even get it to fit on the MG34."