Haha, I don't often post anymore, bit I'm gonna through a spanner in the works here,
One of my daily drivers is a sunskin small v 2010, I only use sunskin springs, a very well known artist mate retuned it to run like his/how he wanted me to tattoo (long through, medium hit).
As I said I only use sunskin springs on this machine, I went through 4 or 5 rear springs (all medium gage) in the first month... The current rear spring has been on it for over a year now, no drama (touch wood!) all from the same spring stock... Every time one would snap, I'd re spring/tune it, get it checked over by said mate and same thing would happen!...
Maybe really small 'micro tuning' differences were to blame... Or maybes just shit sometimes happens!!