If the caps, CCI 11, are loose, you need CCI 10. Not Rem 10s. You will find that the Rem 10s have a larger ID than the CCI 11 does.
If all you can get are 11s, I think your idea should work fine. Personally, I'd just pinch em a bit.
Good luck and enjoy. Cap and Ball revolvers are great fun.
NRA Life Member