My own opinion so take it as you will... I own both a 95 Marlin & an 86 of the Jap variety and I would never "assume" the 86 is stronger than a 95, another assumption you make is that the Pedersoli 86 is equal in strength to both the Marlin & Jap.... this is where we part company on assumptions...Bearbuster rounds have a reputation for being very hot & I wouldnt handhold either of my LEVER guns with them until I had test fired a box thru them tied to a tree or tire.
Now for the bad news for you, I have owned Pedersoli rifles in the past, very fine rifles within their intended purpose but I have worked on dozen of Italian built guns & quite frankly I wouldnt trust any of them to equate a North American built outfit with bearbusters. Now, to be clear I havent seen an Italian rifle blow up ( several pistols tho from the same companies) but i have seen several with streched frames and broken parts from rounds with higher than ordinary "Cowboy" classed rounds
just my opinion so you "do you" and Ill stick to me myself & I.