There are a few reasons this can happen, and it maybe a compilation of them. First, and MOST IMPORTANT, IMO....that is NOT a break shaft, so the ferrule material is not designed for the hard impact of breaking. Their ferrule material is fairly soft as it is expected to be used as a shooter, so there will be flex/compression of the material under duress of breaking and that alone can cause a glue joint to fail, and maybe even the ferrule to become distorted. Next, both the ferrule and tip MUST be totally flat to each other, so when dry fitting it, the tip doesn't rock side to side even a little bit. The glue used is important too, but the most important issue I believe is using the wrong shaft to do breaking duties......
Dave
