We've looked at this several times in the past few years, and I've spent the morning looking at prints and taking measurements with pin gauges and a micrometer. In each case, every component is within the design tolerances. "Tolerance Stacking" occurs when the plus/minus tolerances on each part might well be within spec, but when several parts with tolerances are assembled with/into one another, the combination of tolerances can create fit problems.
A combination (just an example) of a hole at one end of the spec, a pin at the other end, combined with the hole dimensions in the hammer (including j-wire placement tolerances) and/or trigger and you can end up with a fit that is tighter or looser than "standard".
We are continuing to look at the situation, as it concerns us when a customer gets a RRA product that isn't to their expectation. For now, I would try it to see if it works the way you want it to. Make sure your j-pin is holding the hammer pin in place properly (so even if it walksa minimal amount it won't actually come out) and that the legs of the hammer spring are holding properly against the trigger pin. If that isn't satisfactoy or doesn't work, please contact me directly at (309)792-5780, ext 127 and we'll try to work something out.