Tips to make the perfect sample loop in Renoise

Hello Renoise community :)

I have been taking this sound part from an old movie trailer and I wanted to loop it – but I cannot find the point where the loop sounds coherent.
Link: or > 3804 Surf Nazis Must Die - trailer.wav

I tried setting my pattern length long as possible (512) and placing a random note in track 1 and then let it running. After that I opened “sample editor” and sat my loop-mode to “forward” so I can move a start and ending point. The problem is to find the perfect, start and ending point without getting strange sounds when the loop starts over.

Any tips about making loops from a sample?

Posted little over 10 days ago: