If you're talking any kind of rolls, I found multiple rolls of solid silver half dollars once in a batch of CWRs I picked up from my main bank. I ended up with 306 silver halves out of 34 rolls. If you're talking MWRs, I once opened a roll with 6 silvers in it. That box had 7 enders and I totaled 75 silvers from it, my best ever.
This is my best ever silver find: Multiple solid rolls of 90% and 40%ers. These were from a batch of CWR. Best MWR rolls I've had have had 5-6 silver in each roll of halves.
Here’s a true story that I posted on CoinTalk a couple years back. My very first CRH experience was multiple entire rolls of 40%ers. I retired from roll hunting after that, no where to go but downhill!
Ah, the best I've come in a half dollar roll is one 40% silver half in one roll. But, it appears I have quite a bit of competition.