Book loads are pretty safe but keep an eye on vent liner erosion. Once the vent gets to around .035, its a very good idea to replace it. Also make sure the flash channel under the primer stays clean.
Clean it with a 1/8-5/32 drill bit by HAND. Not chucked up in a drill.
As carbon builds in that channel, the volume goes down. As volume lowers, pressure on the primer increases.
You could also try 60-65gr of Reloder7 IF you are shooting 300gr bullets. That data makes less pressure than the faster book powders and pretty close to the same fps. Re7 was one of the original book powders for the ML-I not ML-II.