I haven't the foggiest idea if that is a safe load or not. Have you chronographed it to see what kind of velocities you are getting? With a bullet of given weight, that is a fairly good method (better than felt recoil, at least) of determining if a load is mild, just right, hot or too hot. Just compare it to what you measure with Winchester WB from the same gun.
Whether it will "blow up" your gun probably depends just as much on the condition of your cartridge cases. Star BMs and BKMs, for example, are not very tolerant of previously stretched cases with maximum loads. Model Bs and B Supers are better in this regard, but a case that should be thrown away is still, no matter what anyone says, garbage, and should not be reloaded.
M