I did a search here after breaking the tops off one or two bottles each batch lately using my wing capper. The HBT opinion was either the wing capper itself or a heat related problem from using the extra hot sanitizing setting on the dishwasher. I keg and bottle about 50/50, so figured I’d just live with it.
SWMBO just came back from the flea market with this. Looks old, but tried it out and it works fine. Problem solved!
I forget which brand it was but there was a domestic brand bottle that I was reusing that also tended to break a lot at the neck. Looking at the bottles, I could see stress fractures developing after the first reuse. I just tossed all the ones from that brand and haven't had the problem since.
Were they just one brand bottle or several different?
I kind of like the design of your's bc you just crank up and down, mine you have to get the capper/lever in the right place for each different size bottle. It's not a big issue or anything...just takes getting used to.