Mykeal, you're absolutely right. Measuring from two different tins of Remington #10s I got an average reading of .182 from one tin and .145 from the other, and you're evidently getting yet another measurement from yours, so go figure. I didn't even bother looking at the #11s after I came up with these results. I only use Remington caps, so I don't know how this plays out with CCI and the rest, but I'll take your word for it. I didn't realize that there was this much variation within the same brand before. Thanks for prompting the experiment.
I guess the bottom line is that all of the caps I have used seem to work well with the in-line capper, no matter what size they are. The capper really works to make life easier, and I highly recommend getting one...