I have a bore tech bore guide that i have been using for a while now. I have some nice equipment now and i am wondering if this bore guide i have is good enough? The thing that concerns me is the tips. The tips of my guide are just rubber cones. They are designed as a one size fits most. I was looking at sinclairs and they have fitted cones with o-rings on there guides. Will i hurt anything if i continue to use my rubber coned bore tech bore guide?? When i push the cleaning rod into the guide i can feel a little jump when the rod enters the chamber. this concerns me a bit. any thoughts?? thanks Lee