Originally Posted by
CES
I went through a phase early on where I used the rounded end of a guitar pick on mandolin, and IIRC I started doing it because I thought it would help my tremolo out as well. Played that way for a few months, then moved on to heavier large triangle shaped picks. I've tried Golden Gate, Dawg, and the roundest of the Primetones within the past couple of years, and I can't get any volume/tone with those now. Not sure what happened, but I need at least a little bit of a point these days. But, if round works for you, go for it!!
Also, I used a quarter in a pinch once on guitar, and agree it didn't sound very good. Brian May sure made it work for him, though!!