I also have probs with nose dives.
I always use Win brass and OAL 1.171
My personal experience, with my config it depends on the shape of the bullet.
With round nose no probs, with a flat point nothing but trouble
I got some 185gr FP really cheap so i want to use them.
After reading your post, i'm first going to try load longer; As i was told not to load longer as 1.180 because of possible feed probs and pressure?
My other concern are the mags dimensions causing nose dives?
Current load :
Win brass
Federal primer
MPF FP 185gr bullet
OAL 1.171
VV N340 5.7gr
PF 174