I’ve been trying a 160gr. roundnose cast bullet but so far have not been able to get it to cycle the action using loads based on the155 gr. data i’ve found online. The bullet is scary accurate but i’d need to go beyond the posted data to get it to function. I’ve had great luck however with the RCBS 185 gr. cast/powder coated. I think the gap’s heavy slide makes the 155/160 gr. bullet a difficult proposition. I use Titegroup as well in my g37.