This is probably too late to help, but just some reference points:
135 gr RN. 3.5 gr Titegroup, 1.110″ OAL gave me 990 ft/sec from a Tanfoglio Stock Master (4.75″ bbl) – PF 134.
In the same gun, 124 RN and 124 TC-MW with 3.9 gr of Titegroup and both loaded to the same 1.110″ OAL, the RN bullet shot at 1096 ft/sec, and the TC-MW went 1057 ft/sec.
The 124 RN bullet length is 0.584″, and the TC-MW bullet length is 0.548″. Loaded to the same OAL, the MW leaves more open volume over the powder, hence the lower velocity.
135 RN bullet length is 0.623″, and I suspect the 135 MW will be shorter and will yield a lower velocity than the RN, for the same powder charge and OAL. The 1.100″ OAL I think is short enough to chamber in the majority of contemporary 9mm barrels, although M&Ps seem to run shallow chambers. My suggestion is to start at that OAL with 3.3 gr of Titegroup and see how that works for you.
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