IMHO owning a trapdoor is hold it close like a shotgun not caring about hittin papper till you get a idea.Ohshit. Don't shoot it, brother. Or get sumbody to shoot it once and give you an idea of the kick to see if it is reasonable.
"A man has to know his limitations."
That ain't hyperbole. I did the six weeks of shoulder in a giant sling thing for rotator shoulder... so I know for double-certain since you've done it, too that caution is not cowardice.
The trap foor is a heavy rifle though.
"45-70" in Italian means cost a lot to shoot