If you follow the old rule of thumb to reduce the maximum charge 10%, then:
41.0 grs × 0.9 grs = 36.9 grs. 37 grs is close enough.
If you follow Richard Lee's 2% per step rule for checking, rounding each value, you have:
37.0 grs
37.8 grs
38.6 grs
39.4 grs
40.2 grs
41.0 grs
Make up a couple of extra 37 grs loads to foul the bore with, then fire each one in the series from low to high, inspecting for
pressure signs after each shot.
As I say, I doubt you'll wind up differently from where you were before, so I don't think you'll need to shoot large groups at each stage. It's just a quick 8 round safety check for differences. If you do think you've got a pressure sign on one, then stop, obviously, and do more statistically significant sample size testing.