Not wanting to up set the OP of this tread (very nice rifle by the way), but I have seen a lot of BP doubles reproved for Nitro & these are considered safe after they have been reproved, there is no magic in reproving only testing the strength of the action at that time, I have also read of many people in old Africa shooting there 450BP with the full nitro load the only down side was the heavier recoil, so they said, I can imagine it made them loss sooner ?

Even if this rifle was NP it would have been better left in 450 in either way I'm thinking ?