Spoke failure question
I have a wheel set built up with Open Pro rims,DT Swiss swagged spokes, DA-7700 hubs.
The wheel went out of true. So I check the spoke tension, I find a spoke that's loose. So I try to tighten it up, no luck. I run out of thread before proper tension is built up, it's like the spoke is too long. I take out a good spoke and the problematic one, the problematic one is about 7-8mm longer. I know I used the same spokes for this wheel set and didn't have any odd length ones.
This is the second time I've had a spoke elongate itself like this... Last time this happened, I thought I just used a wrong spoke by mistake when building the wheel. I tensioned the wheel fine and ~250 miles later same thing happens... The first time this happened, I've had about 3k miles on the wheels.
I've never built up a wheel with swagged spokes before, only straight gauge. Is this how swagged spokes fail?