I stopped in today (Saturday) looking for some Butler Creek Blizzard flip-up scope covers for my Aimpoint CompC3. I measured the scope ends and picked the sizes from Butler Creek's website table, which proved to not be the same as the actual packaging.
Luckily I had my M4 in the car, so I asked Bill if I could just go get it to make sure it fit. He was happy to help and said "let's make sure you get what you need. . ."
Although the place was packed and it took Bill several minutes to be able to get to me, once he did he was very helpful. He spent several minutes trying different sized covers until we found the ones that actually fit.
The covers were priced about $3 higher than online dealers, but still half what the factory Aimpoint covers cost. All-in-all a good trip.
+1 for "Bill W." and Gander Greenwood.