I recently purchased the 5lb bag of colored caps from AHS and the last 2 batches I capped have not carbed properly. Some have been fine, while others had no carbonation at all. I've bottled 20 batches or so with no trouble <knock on wood>. I just bottled another batch this morning and I am trying to figure out whats going on. I noticed after I capped a bottle, the cap can twist still. I am using a bench capper. I've never checked before, so I'm not sure if any other batches have been like that. I always turn upside down for a leak check, but never check this. I used my wing capper to hit any of the loose ones again, and they seemed to tighten a bit more with no more twisting of the cap. I don't know if the bench capper is wearing out, the caps are bad, the bottles are bad or what else could be causing this, but I need to get to the bottom of it before I get too far along. I reuse my bottles, and the majority are Sam Adams bottles.