This customer had an older model that required shorter nipples than the standard size. We sent him a set of our pocket revolver nipples, which fit correctly.
This should be a straightforward repair. The issue appears to be with the revolver rather than the nipples. We recommend having it inspected by a qualified gunsmith who is experienced with black-powder revolvers. The timing may require adjustment, some tolerances may be out of specification, or a burr in the hammer notch may be causing the problem.
The recommended caps for our nipples are clearly identified on the product page, FAQ page, and product packaging. CCI No. 10 caps are not included among the recommended options because their smaller internal diameter prevents them from fitting correctly.
These products are recommended with items in your cart.