CaptCurl
No it does not make me suspect of RL 15.\
This is the first blow up with reloads I am aware of with RL 15. I know of a blow up with Federal factory 470, and I have read there were two in Europe with Federal Factory.

There have been blow ups with IMR 3031 and IMR 4831.
My current belief is that it does not make ANY difference which powder you use in your double rifle. I do not think the problem is related to the burn rate of a particular powder. I think the problem is with older barrel steel. The 3 sets of blown barrels I have seen have all been from doubles prior to WW1.
It does seem strange that the bbls I have seen have all burst just in front of the forend, [and away from the ribs which I can understand as it is the path of least resistance].
I have used IMR 4198, IMR 4831, and RL 15 in my 450 No2 and my 450/400 3 1/4", as well as a lot of IMR 3031 in the 450 No2. I have a lot of rounds through these rifles with no problems.

When brass and bullets again became avialable for vintage doubles IMR 3031 was the powder of choice, some guns blew up. Several people then recommended IMR 4831, and some guns blew up, now RL15 is the powder of choice, and some guns have blown up, even with the Federal Factory load.
What I would like to know if someone who had been shooting his double with one powder, then switched to another, and THEN blew up a bbl. OR these bbl blow ups the result of a double that has not been used since the early rebirth, and are just now being pressed back into service.
Also are the blow ups related to a specific time period or a specific barrel maker?

That is the type of info I am researching.