One of the reasons for the charge weight changes in loading manuals over the years is the methods of measuring pressures have changed. They used to use CUP, which was crushing a copper pellet, it worked, but was not overly reliable.
There have since been tests where they found the old CUP data was running pressures a lot higher than they thought they were, and there was also data that was published by measuring case head expansion only. Now they use PSI to measure pressures along with strain gauges and other accessories, they found some of the older data to be up over 70,000 psi., but, with CUP, listed at under 60,000. They found some data was out as much as 15% apparently. Change a powder lot with that kind of an error in the data and you could concievably be in trouble by going back to the same load, or data from an old manual, as you used on the old lot.
And you can't judge what your rifle will tolerate until you have worked it up from the starting load, some guns max out a lot quicker than others, some lots of powders do ,too.
The OP's 45gr load may be OK, it also may not be. His gun is different than the test gun, different than his buddy's gun, and it doesn't sound to me like he was working an OCW ladder from the way he presented what he did.