I don't think all amp openers are made that well. The one I tried didn't score the amp that well and I had problems using it. Actually it didn't score the amp at all. I think that some are good and some are not.
What I do now is use a cut off wheel for a dremel. It's like a round stone. I score the amp with that then use the pen cap. Comes off clean now everytime.
i use a pair of jeans slip the amp in the pocket, find the neck and snap, always a nice clean break. the worst thing that happened to me when i opened my first amp was i cut my thumb urgh it hurt so much when you put pressure on it i.e. holding the syringe!
I don't think all amp openers are made that well. The one I tried didn't score the amp that well and I had problems using it. Actually it didn't score the amp at all. I think that some are good and some are not.
What I do now is use a cut off wheel for a dremel. It's like a round stone. I score the amp with that then use the pen cap. Comes off clean now everytime.