When I use paracord for slings, I go with the cheap route of cutting it and then melting the end with a BIC lighter. For 550 I have the timing down pretty good. You hit the end with the flame, give it a brief moment, then grab it with your fingers to remold as desired.
I'm working on a couple slings now with 425. Wow! This stuff seems to be way hotter. I learned really quickly that the timing for 425 isn't the same as 550. I've got a couple annoying burns on my index finger.
But after melting more than 20 ends, I still don't seem to have the timing figured out as well as with 550 cord.
The 'Subject' of this topic was just a joke. I think the real problem is the 425 cord has less material. So there is a shorter amount of time between burning your fingers and still being able to manipulate the melted end. Too short of a time for me so far.
I think that's my first rant on paracord.