i use Grolsch style growlers and never had a problem never used the screw on top ones. before i tried to bottle with them i read online about what people thought about using them and everyone talked as if they were the most dangerous things to use for bottling. I dont see why since the bottles i have are good thick glass with a good seal as long as you dont over prime then i can't see them being a problem. A side note my sister one time got a grolsh growler at a brewery for her boyfriend poured a glass for him the one night then left it open. i was over her house the next day saw it open closed it and never thought of it till a month later when i saw it. i opened the growler up the top blew off with a lot of force and shot the one metal piece that holds it on the bottle across the room. that could have been dangerous if it hit somebody in the eye or possibly the neck but the bottle itself was still in good condition (i contemplated stealing the growler and using it for bottling but i dont trust it after the explosion).